1014-00003 · Optiwave Semiconductor Corp · Fact Discovery

meet-confer-letter-bhs-discovery.docx DOCUMENT Litigation

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CALDERWOOD & HARKNESS LLP Counselors at Law

One Embarcadero Center, 34th Floor San Francisco, California 94111 Telephone: (415) 792-8400 Facsimile: (415) 792-8401 www.calderwoodharkness.com

January 18, 2023

Via Email and U.S. Mail

Daniel Kowalski, Esq. Associate Team Lead, intellectual Property Litigation Group Brannick Howell & Stein LLP 555 California Street, Suite 2800 San Francisco, CA 94104

Re: Optiwave Semiconductor Corp. v. Lumos Photonics, Inc., Case No. 5:22-cv-03417-EJD (N.D. Cal.) — Deficiencies in Defendant's Document Production and Interrogatory Responses; Meet-and-Confer Pursuant to Federal Rule of Civil Procedure 37(a)(1) and N.D. Cal. Local Rule 37-1

Dear Mr. Kowalski:

I. Introduction and Purpose of Letter

This firm represents plaintiff Optiwave Semiconductor Corp. ("OWS" or "Optiwave") in the above-captioned patent infringement action against Lumos Photonics, Inc. ("Lumos"), currently pending before the Honorable Edward J. Torvelis in the United States District Court for the Northern District of California. We write to you in your capacity as Associate Team Lead of Brannick Howell & Stein LLP's ("BHS") intellectual Property Litigation Group and as counsel of record for Lumos in this matter.

This letter constitutes a formal meet-and-confer communication pursuant to Federal Rule of Civil Procedure 37(a)(1) and Northern District of California Local Rule 37-1 regarding material deficiencies that OWS has identified in Lumos's responses to OWS's First Set of Requests for Production of Documents (Nos. 1–112) and OWS's First Set of Interrogatories (Nos. 1–25), both of which were served on Lumos on November 21, 2022. Lumos served its responses and objections to the First Set of Requests for Production on December 21, 2022, and its responses and objections to the First Set of Interrogatories on December 22, 2022. Following a thorough review of those responses, including the documents produced to date on Lumos's document review platform, we have identified a number of material deficiencies that require supplementation and cure.

We write in the spirit of cooperation and with the sincere hope that these issues can be resolved without the need for judicial intervention. To that end, we respectfully request that BHS make counsel available for a meet-and-confer conference within seven (7) days of the date of this letter to discuss the deficiencies outlined herein and to negotiate a reasonable supplementation schedule. In addition, we request that Lumos provide supplemental production and supplemental interrogatory responses within fourteen (14) days of the date of this letter — that is, by no later than February 1, 2023.

At the outset, we note that the Stipulated Protective Order entered by the Court on September 16, 2022 (Dkt. No. 48) provides robust protections for commercially sensitive and proprietary information, including a "Highly Confidential — Attorneys' Eyes Only" designation tier that restricts access to outside litigation counsel and designated experts. The protections afforded by the Stipulated Protective Order should substantially address any confidentiality or trade secret concerns that Lumos may have with respect to the categories of documents and information discussed in this letter. Blanket assertions of confidentiality or trade secret protection, without more, cannot justify the wholesale withholding of documents that are plainly relevant to the claims and defenses in this action.

II. Background on discovery Requests

By way of brief background, OWS served its First Set of Requests for Production of Documents (comprising 112 individual requests) and its First Set of Interrogatories (comprising 25 interrogatories) on November 21, 2022, in accordance with the Case Management Order entered by Judge Torvelis on August 22, 2022 (Dkt. No. 39). Lumos, for its part, served its own First Set of Document Requests (comprising 98 requests) on November 7, 2022. OWS timely served its responses and objections to Lumos's First Set on December 7, 2022, and has produced a substantial volume of responsive documents in accordance with those responses, including detailed claim charts, prosecution histories, and technical documentation relating to OWS's patented technologies.

As the Court and the parties are aware, this action involves the infringement of four United States patents owned by OWS:

• U.S. Patent No. 10,234,567 (the "'567 Patent") — entitled "Integrated Waveguide Coupler for Silicon Photonic Platforms," directed to an adiabatically coupled tapered silicon waveguide structure for efficient optical coupling in silicon photonic integrated circuits;

• U.S. Patent No. 10,891,234 (the "'234 Patent") — entitled "Germanium-on-Silicon Photodetector with Graded Buffer Layer," directed to a high-responsivity germanium photodetector integrated on a silicon substrate using a graded buffer layer having a continuously varying germanium concentration;

• U.S. Patent No. 11,045,678 (the "'678 Patent") — entitled "Multi-Channel Optical Transceiver with Integrated Wavelength Division Multiplexing," directed to a multi-channel optical transceiver monolithically formed on a single silicon die with integrated wavelength division multiplexing (WDM) functionality; and

• U.S. Patent No. 11,312,890 (the "'890 Patent") — entitled "Driver Circuit Architecture for Mach-Zehnder Modulator Systems," directed to a pre-emphasis equalization driver circuit architecture electrically co-integrated with a high-speed silicon photonic Mach-Zehnder modulator on a common substrate.

OWS has accused two primary Lumos products of infringing one or more claims of each of the patents-in-suit: (1) the LumosBridge™ 800G Optical Engine, a silicon photonic optical engine designed for hyperscale data center interconnects, which first shipped commercially in Q1 2022 and carries a unit price in the range of $1,200 to $1,800 depending on configuration; and (2) the LumosEdge™ 400ZR+ Pluggable Transceiver, a coherent pluggable optical transceiver in QSFP-DD form factor designed for metro and edge network applications, which has been in production since Q3 2021 and carries a unit price in the range of $600 to $900 depending on configuration.

The parties are currently engaged in claim construction proceedings. OWS filed its Opening Claim Construction Brief on December 5, 2022 (Dkt. No. 72), proposing constructions for fourteen disputed claim terms across the four patents-in-suit. Lumos filed its Responsive Claim Construction Brief on December 19, 2022 (Dkt. No. 78). The Markman hearing is currently scheduled for January 30, 2023 before Judge Torvelis. OWS acknowledges that certain aspects of the infringement analysis may be refined following the Court's claim construction ruling. However, the outstanding discovery identified in this letter is critical not only for the infringement analysis but also for the broader fact discovery that will proceed in parallel with and following claim construction, including discovery relating to damages, willfulness, and the validity defenses Lumos has asserted in its counterclaims. Delay in obtaining this discovery will prejudice OWS's ability to meet the discovery deadlines established in the Case Management Order.

III. Deficiency Category 1: Technical Design Documents for the LumosBridge™ 800G Optical Engine

A. Specific Requests at Issue

OWS's First Set of Requests for Production included numerous requests directed at the internal design and engineering documentation for the LumosBridge™ 800G Optical Engine, which is one of the two primary accused products in this action. The requests at issue include, without limitation, RFP Nos. 5, 7, 9, 12, 14, 17, 21, 23, 26, 28, 31, and 34, which collectively sought the following categories of documents:

(a) Design specifications and architecture documents for the LumosBridge 800G optical engine, including system-level block diagrams, interface specifications, optical link budget analyses, and design review presentations;

(b) Photonic integrated circuit ("PIC") layout files and associated design rule check ("DRC") reports, including GDS-II or OASIS format layout files for the silicon photonic die;

(c) Waveguide coupler design documents, including taper geometry specifications, coupling efficiency simulation results, and fabrication process specifications — these are directly relevant to the '567 Patent's claimed limitation of an "adiabatically coupled" tapered silicon waveguide structure, and OWS requires these documents to determine whether Lumos's waveguide coupler design practices an adiabatic taper or an alternative coupling geometry;

(d) Germanium photodetector design documents, including buffer layer composition specifications, epitaxial growth recipes, and material characterization data (e.g., X-ray diffraction, secondary ion mass spectrometry, or transmission electron microscopy data characterizing the SiGe buffer layer) — these are directly relevant to the '234 Patent's claimed limitation of a "graded buffer layer having a continuously varying germanium concentration," and OWS requires these documents to assess whether Lumos's buffer layer uses a continuously graded or step-graded germanium composition profile;

(e) Documents relating to the micro-transfer-printing process for III-V gain elements bonded to the silicon PIC, including process flow documents, alignment tolerances, and bonding specifications — these are relevant to the '678 Patent's claimed limitation requiring the transceiver to be "monolithically formed on a single silicon die," and OWS requires these documents to evaluate whether Lumos's heterogeneous integration approach satisfies or avoids this limitation; and

(f) Driver circuit integration documents, including flip-chip bonding specifications for the CMOS driver die, copper pillar micro-bump design specifications, and electrical interconnect characterization data — these are relevant to the '890 Patent's claimed "co-integrated" limitation, and OWS requires these documents to evaluate the physical integration architecture between the driver circuit die and the silicon photonic modulator die in the LumosBridge 800G product.

B. Nature of Deficiency

Lumos's production in response to these requests is materially deficient. The documents produced to date consist exclusively of marketing datasheets, publicly available product briefs and application notes, and high-level functional block diagrams — all of which are already publicly available on Lumos's website and in its investor presentations. These documents contain no meaningful technical detail regarding the internal design of the LumosBridge 800G and are wholly inadequate for the purpose of conducting an infringement analysis.

Specifically, Lumos has not produced any of the following categories of responsive documents that unquestionably exist for a product that has been in commercial production since Q1 2022:

• Internal engineering design documents, including design specifications, design review presentations (e.g., PDR, CDR), and engineering change orders;

• Detailed photonic circuit layout files (GDS-II or equivalent);

• Process flow documents describing the silicon photonic fabrication process;

• Epitaxial layer stackup specifications and growth recipes for the germanium photodetector and SiGe buffer layers;

• Material characterization and metrology data for the photodetector structures;

• Integration methodology documents describing the micro-transfer-printing process and the flip-chip bonding process; and

• Simulation and modeling reports for the waveguide coupler, photodetector, modulator, and driver circuit subsystems.

In its responses to the relevant RFPs, Lumos interposed boilerplate objections asserting that the requests were "overbroad," "unduly burdensome," and sought "trade secrets and proprietary information." These objections are insufficient under the Federal Rules. Lumos did not identify with any specificity which documents were being withheld on the basis of these objections, did not explain the basis for the overbreadth or burden claims, and did not propose any narrowing modifications that might address its concerns while still providing OWS with the discovery to which it is entitled. A party resisting discovery on grounds of overbreadth or burden bears the burden of demonstrating that the discovery sought is disproportionate to the needs of the case. See Fed. R. Civ. P. 26(b)(1); Carr v. Brightmoor Indemnity Co., 312 F.R.D. 459, 468 (N.D. Tex. 2015). Lumos has made no such showing.

As to trade secret concerns, we reiterate that the Stipulated Protective Order entered by the Court on September 16, 2022, provides a Highly Confidential — Attorneys' Eyes Only designation tier that restricts access to outside litigation counsel, designated experts, and their support staff. This designation is specifically designed to accommodate the production of commercially sensitive technical documents such as the ones at issue here. The existence of the Protective Order eliminates any legitimate basis for withholding responsive design documents on trade secret grounds. See Adidas Am., Inc. v. TRB Acquisitions LLC, No. 15-cv-02113-KAW, 2016 WL 1637473, at *3 (N.D. Cal. Apr. 26, 2016) (ordering production of trade secret documents under protective order in patent case).

The importance of these documents cannot be overstated. The LumosBridge 800G is a primary accused product that has been generating substantial commercial revenue for Lumos since its launch in Q1 2022, with unit prices ranging from $1,200 to $1,800. Detailed internal technical documents are essential to OWS's infringement analysis under each of the four patents-in-suit. OWS's technical expert, Dr. Harold Whitfield of Whitfield Technical Consulting Group, Inc. (retained in August 2022), cannot complete his infringement analysis based solely on marketing materials and high-level block diagrams that omit the precise technical details necessary to evaluate whether the accused product practices the claimed limitations.

By way of specific example, and without limitation, OWS requires documents sufficient to determine:

(a) Whether Lumos's waveguide coupler in the LumosBridge 800G uses a segmented (non-continuous) taper with discrete coupling sections — as Lumos may contend in its non-infringement defense with respect to the '567 Patent — versus a continuous adiabatic taper as claimed in the '567 Patent. The taper geometry specifications, coupling simulation data, and fabrication process documents will be critical to resolving this issue.

(b) The germanium concentration profile in the SiGe buffer layers of the germanium photodetector. Based on publicly available technical conference presentations by Lumos engineers (including Dr. Mei-Ling Zhao's presentation at the 2022 Optical Fiber Communication Conference), OWS understands that the LumosBridge 800G photodetector may use a step-graded buffer with four discrete composition steps at germanium fractions of approximately 0.25, 0.50, 0.75, and 1.0, rather than a continuously varying germanium concentration as claimed in the '234 Patent. The epitaxial growth recipes, material characterization data, and process specifications will be essential to evaluating this issue and to assessing whether Lumos's step-graded approach falls within or outside the scope of the '234 Patent's claims under the doctrine of equivalents.

(c) The specifics of the micro-transfer-printed III-V gain element bonding process used to integrate laser gain elements onto the silicon PIC in the LumosBridge 800G product, which is relevant to the '678 Patent's "monolithically formed on a single silicon die" limitation. OWS requires process flow documents, bonding specifications, and integration methodology documents to evaluate whether Lumos's heterogeneous integration approach satisfies the "monolithically formed" limitation.

(d) The flip-chip bonding architecture between the separate CMOS driver die and the silicon photonic modulator die in the LumosBridge 800G product. The '890 Patent claims a driver circuit "co-integrated" with the modulator, and the physical integration architecture — including the copper pillar micro-bump specifications, die-to-die interconnect parasitics, and signal integrity characteristics — is critical to the infringement analysis under the '890 Patent.

C. Relief Requested

OWS requests that Lumos produce all responsive internal design documents for the LumosBridge™ 800G Optical Engine, including but not limited to: photonic circuit layout files (in native GDS-II, OASIS, or equivalent format); design specifications and architecture documents; process integration and process flow documents; epitaxial growth specifications and material characterization data; waveguide coupler design and simulation documents; photodetector design documents; micro-transfer-printing process documents; flip-chip bonding process and copper pillar micro-bump design documents; driver circuit integration documents; design review presentations; and engineering change orders. Lumos may designate any or all such documents as "Highly Confidential — Attorneys' Eyes Only" under the Stipulated Protective Order. OWS requests that this production be completed within fourteen (14) days of the date of this letter.

IV. Deficiency Category 2: Technical Design Documents for the LumosEdge™ 400ZR+ Pluggable Transceiver

A. Specific Requests at Issue

OWS's First Set of Requests for Production also included requests specifically directed at the internal design and engineering documentation for the second accused product, the LumosEdge™ 400ZR+ Pluggable Transceiver. The requests at issue include RFP Nos. 6, 8, 10, 13, 15, 18, 22, 24, 27, 29, 32, and 35, which sought the following categories of documents:

(a) QSFP-DD module design specifications, including mechanical, thermal, and electrical design documents for the pluggable transceiver module;

(b) Silicon photonics engine design documents for the photonic integrated circuit within the pluggable module, including PIC layout files, process flow documents, and design review presentations;

(c) Waveguide coupling architecture documents, including taper geometry specifications and coupling efficiency data relevant to the '567 Patent;

(d) Photodetector design documents, including germanium photodetector and SiGe buffer layer specifications relevant to the '234 Patent;

(e) Multi-channel optical transceiver and WDM integration documents relevant to the '678 Patent; and

(f) Modulator driver circuit architecture and integration approach documents, including the physical integration of the driver die with the silicon photonic die, relevant to the '890 Patent.

B. Nature of Deficiency

Lumos's production in response to these requests suffers from the same fundamental deficiency identified with respect to the LumosBridge 800G above. Lumos has produced only public-facing product documentation — datasheets, product briefs, and high-level specifications — without producing any internal design files, engineering change orders, design review presentations, manufacturing process documents, or any of the other categories of internal engineering documents that are plainly responsive to these requests and that must exist for a product that has been in commercial production since Q3 2021.

The LumosEdge™ 400ZR+ is a separately accused product that has been generating substantial revenue for Lumos since its commercial launch in Q3 2021. With unit prices in the $600 to $900 range, the LumosEdge product line represents a significant portion of Lumos's accused product revenue. The LumosEdge employs a different form factor (QSFP-DD pluggable) and may employ different internal design choices compared to the LumosBridge 800G optical engine, which means that a separate and independent infringement analysis is required for this product. OWS cannot conduct that analysis based on marketing materials alone.

Lumos's objections to these requests mirrored the blanket objections interposed in response to the LumosBridge-related requests: assertions of overbreadth, undue burden, and trade secret protection, without any specificity as to which documents are being withheld or why. These objections fail to comply with the requirements of Federal Rule of Civil Procedure 34(b)(2)(B), which mandates that objections "state with specificity the grounds for objecting to the request, including the reasons" and further requires that an objection "state whether any responsive materials are being withheld on the basis of that objection." Fed. R. Civ. P. 34(b)(2)(C). Lumos's responses do not satisfy this standard, and the blanket objections should be deemed waived to the extent they are not accompanied by the specificity required by the Rules. See Burlington N. & Santa Fe Ry. Co. v. U.S. Dist. Court for the Dist. of Mont., 408 F.3d 1142, 1149 (9th Cir. 2005).

C. Relief Requested

OWS requests that Lumos produce the full universe of internal engineering and design documents for the LumosEdge™ 400ZR+ Pluggable Transceiver, including the same categories of documents identified in Section III.C above as applied to the LumosEdge product. As with the LumosBridge documents, Lumos may designate any or all such documents as "Highly Confidential — Attorneys' Eyes Only" under the Stipulated Protective Order. OWS requests that this production be completed within fourteen (14) days of the date of this letter.

V. Deficiency Category 3: Source Code for Driver Circuit Firmware

A. Specific Requests at Issue

OWS's First Set of Requests for Production included requests directed at source code, firmware, and embedded software for the driver circuits used in both the LumosBridge 800G Optical Engine and the LumosEdge 400ZR+ Pluggable Transceiver. The requests at issue include RFP Nos. 38, 39, 41, 42, and 44, which collectively sought all source code, firmware, embedded software, and related documentation (including version control histories, change logs, and design documentation) for the driver circuit subsystems of the accused products.

These requests are directly relevant to the '890 Patent, which is directed to a driver circuit architecture for high-speed silicon photonic Mach-Zehnder modulators. Among the asserted claims of the '890 Patent, Claims 1, 5, 8, and 13 each recite, in relevant part, a "pre-emphasis equalization stage electrically co-integrated with the modulator on a common substrate." The pre-emphasis equalization function in the accused products is implemented at least in part through firmware executing on the driver circuit ASIC or DSP. The firmware that controls the pre-emphasis equalization algorithm — including the tap coefficients, adaptation logic, and signal conditioning parameters — is therefore directly relevant to OWS's infringement analysis under the '890 Patent. Without access to the source code, OWS's technical expert, Dr. Whitfield, cannot fully evaluate how the pre-emphasis equalization is implemented in the accused products or whether the firmware-controlled equalization stage satisfies the "co-integrated" limitation of the asserted claims.

B. Nature of Deficiency

Lumos objected to the production of source code in its entirety, categorically refusing to produce any source code or firmware for the driver circuit subsystems. Lumos's objections cited trade secret protection and proportionality concerns under Rule 26(b)(1), asserting that the source code constitutes "highly sensitive proprietary trade secrets" and that production would impose "undue burden" on Lumos.

These objections are without merit. First, the source code at issue is directly relevant to the infringement analysis under the '890 Patent, and Lumos has not articulated any basis for contending otherwise. The relevance of the source code is not in dispute. Second, Lumos did not offer any compromise or alternative accommodation in its objections — no source code inspection protocol, no stand-alone secure room review, no source code escrow arrangement, and no proposal for production of limited relevant portions of the codebase. A wholesale refusal to produce source code, without any attempt to propose a reasonable accommodation, is inconsistent with the cooperation obligations imposed by the Federal Rules and the Northern District's Patent Local Rules.

Third, we have reviewed Lumos's privilege log (to the extent one was produced — as discussed in Section VIII below, the privilege log itself is deficient), and no entry on the privilege log identifies source code as being withheld on the basis of attorney-client privilege or work product protection. Lumos's objection is therefore based solely on relevance, burden, and trade secret grounds — not privilege. The trade secret concern, as discussed above, is fully addressed by the Stipulated Protective Order's Highly Confidential — Attorneys' Eyes Only designation tier.

Source code inspection is routine in patent infringement cases involving electronic circuits, firmware, and software-controlled functionality. Courts in this District and elsewhere have repeatedly ordered the production of or access to source code in patent cases, subject to appropriate protective order provisions. See, e.g., Ridgeline Industries Am., Inc. v. Stonefield & Co., No. 10-cv-03561-WHA, 2011 WL 3794892 (N.D. Cal. Aug. 26, 2011); Camberwell & Co. v. Northgate & Co. Elecs. Co., No. 11-cv-01846-LHK, 2012 WL 1067548 (N.D. Cal. Mar. 27, 2012). There is no basis for Lumos's categorical refusal to provide any access to the relevant source code.

OWS's designated technical expert, Dr. Harold Whitfield of Whitfield Technical Consulting Group, Inc. (retained August 2022), requires access to the driver circuit firmware source code to complete his infringement analysis with respect to the '890 Patent. Dr. Whitfield has extensive experience in silicon photonic circuit design and driver circuit architecture, including over twenty-five years of experience in the semiconductor industry and prior service as an expert in numerous patent infringement cases involving source code review. Dr. Whitfield is prepared to review the source code under the most restrictive protections available under the Stipulated Protective Order and under any additional source code inspection protocol that the parties may agree upon.

C. Proposed Source Code Inspection Protocol

In the interest of addressing Lumos's stated concerns regarding trade secret protection, OWS proposes the following source code inspection protocol as a reasonable accommodation:

1. Location: The inspection shall take place at a Lumos facility, at Lumos's election: either the Santa Clara office located at 4750 Great America Parkway, Suite 320, Santa Clara, CA 95054, or the Hillsboro, Oregon fabrication facility located at 3200 NE Shute Road, Hillsboro, OR 97124.

2. Access: Inspection shall be limited to OWS's outside litigation counsel (specifically, attorneys at Calderwood & Harkness LLP who are admitted to the bar of this Court and who have signed the Stipulated Protective Order) and OWS's designated technical expert, Dr. Harold Whitfield, each of whom shall have executed the Stipulated Protective Order's acknowledgment and agreement to be bound.

3. Designation: All source code materials made available for inspection shall be designated "Highly Confidential — Attorneys' Eyes Only" under the Stipulated Protective Order.

4. No Copying: No electronic or photographic copying of source code shall be permitted. Inspecting parties may take handwritten notes during the inspection, and such notes shall be subject to the Stipulated Protective Order's Highly Confidential — Attorneys' Eyes Only restrictions.

5. Duration: OWS proposes an initial inspection period of up to three (3) business days, with the parties to confer regarding any need for additional inspection time.

6. Timing: OWS proposes that the inspection occur within twenty-one (21) days of the date of this letter (i.e., by February 8, 2023), with specific dates to be coordinated between counsel.

This proposed protocol is consistent with source code inspection protocols routinely employed in patent cases in this District and provides robust protections against any unauthorized use or disclosure of Lumos's proprietary code.

D. Relief Requested

OWS requests that the parties agree upon a source code inspection protocol, based on the framework proposed above or a mutually agreeable alternative, within fourteen (14) days of the date of this letter. OWS further requests that the source code inspection itself take place within twenty-one (21) days of the date of this letter. In the alternative, if Lumos prefers to produce the relevant portions of the driver circuit firmware source code rather than host an on-site inspection, OWS will accept production of the relevant source code on a secure, encrypted medium (e.g., an encrypted hard drive or secure virtual data room) under the Highly Confidential — Attorneys' Eyes Only designation of the Stipulated Protective Order.

VI. Deficiency Category 4: Revenue Breakdowns by Product Configuration

A. Specific Requests at Issue

OWS's First Set of Requests for Production and First Set of Interrogatories included requests directed at revenue and financial data for the accused products. The requests at issue include RFP Nos. 52, 54, 56, 58, 60, and 62 and Interrogatory Nos. 14, 15, 16, and 17, which collectively sought revenue data for the LumosBridge 800G and LumosEdge 400ZR+ products broken down by the following categories:

(a) Product line — i.e., revenue attributable to the LumosBridge™ 800G Optical Engine versus revenue attributable to the LumosEdge™ 400ZR+ Pluggable Transceiver;

(b) Product configuration / SKU — i.e., revenue attributable to each individual product configuration or stock keeping unit within each product line, including different data rate, reach, and interface configurations;

(d) Geographic region — i.e., revenue attributable to sales in specific geographic regions, with a specific focus on sales within or shipped to or from the Northern District of California; and

(e) Quarter — i.e., revenue data on a quarterly basis from Q1 2021 through Q4 2022 (and any available data for Q1 2023).

These data are directly relevant to OWS's damages analysis. OWS's claimed damages exceed $75 million based on a reasonable royalty theory, calculated by applying an estimated 7.5% royalty rate to the accused products' revenue base, with the potential for enhanced damages based on willfulness. According to Lumos's most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission, the combined revenue from the accused product lines for calendar year 2022 was approximately $148.6 million, with approximately $62.3 million attributable to Q1 and Q2 2022 — the pre-suit damages period before this action was filed on June 17, 2022. OWS's designated damages expert, Dr. Lawrence Kessler of Apex Claim Analytics LLC (retained October 2022), requires granular, product-level and customer-level revenue data in order to perform a reliable Georgia-Pacific reasonable royalty analysis and to quantify OWS's damages with the specificity required by Uniloc USA, Inc. v. Kestrel Partners LLC, 632 F.3d 1292 (Fed. Cir. 2011), and its progeny.

B. Nature of Deficiency

Lumos's document production and interrogatory responses regarding revenue data are substantively deficient. In its document production, Lumos produced only the aggregate revenue figures that are publicly available from its Form 10-K filing and its quarterly reports on Form 10-Q. Lumos Photonics is a publicly traded company listed on the Nasdaq Stock Market under the ticker symbol LMPH, and OWS already had access to the same aggregate financial data through Lumos's public filings. No additional internal financial data — no breakdown by individual accused product, no breakdown by product configuration or SKU, no customer-level data, and no geographic breakdown — was produced.

Lumos's interrogatory responses regarding revenue were equally deficient. In response to Interrogatory Nos. 14 through 17, Lumos merely cross-referenced its publicly filed 10-K and 10-Q reports and stated that "further detail regarding revenue by product line, configuration, customer, and geography is proprietary and competitively sensitive business information" that Lumos declined to produce. This is not an adequate interrogatory response under Federal Rule of Civil Procedure 33(b)(3), which requires that each interrogatory be answered "separately and fully in writing under oath." An interrogatory response that simply directs the propounding party to publicly available documents without providing any additional substantive information does not satisfy this standard. See Pulsecard, Inc. v. Discover Card Servs., Inc., 168 F.R.D. 295, 310 (D. Kan. 1996).

Aggregate, publicly available revenue data is manifestly insufficient for a meaningful damages analysis in a patent infringement case of this magnitude. Configuration-level pricing data is critical given the significant price ranges within each product line — the LumosBridge 800G ranges from $1,200 to $1,800 per unit and the LumosEdge 400ZR+ ranges from $600 to $900 per unit, meaning that the specific mix of configurations sold has a material impact on the royalty base calculation. Customer-level data is necessary to assess the reasonable royalty base and to evaluate multiple Georgia-Pacific factors, including but not limited to: the commercial relationship between OWS and Lumos (Georgia-Pacific factor 4); the effect of selling the patented specialty or the unpatented product in promoting sales of other products of the licensee (Georgia-Pacific factor 6); the portion of the profit or of the selling price that may be customary in the particular business or in comparable businesses to allow for the use of the invention or analogous inventions (Georgia-Pacific factor 12); and the portion of the realizable profit that should be credited to the invention as distinguished from non-patented elements (Georgia-Pacific factor 13). Geographic data is separately necessary to establish the proper damages base for sales within the jurisdiction.

C. Relief Requested

OWS requests that Lumos provide supplemental interrogatory responses and supplemental document production providing accused product revenue data broken down by: (i) product line (LumosBridge 800G vs. LumosEdge 400ZR+); (ii) product configuration/SKU; (iii) customer; (iv) quarter; and (v) geographic region (including sales within the Northern District of California). This data should cover the period from Q3 2021 (when the LumosEdge 400ZR+ entered production) through Q4 2022, and any available data for Q1 2023. Lumos may designate all such financial data as "Highly Confidential — Attorneys' Eyes Only" under the Stipulated Protective Order. OWS requests that this supplemental production and these supplemental responses be provided within fourteen (14) days of the date of this letter.

VII. Deficiency Category 5: Interrogatory Responses Regarding Non-Infringement and Invalidity Contentions

A. Specific Interrogatories at Issue

OWS's First Set of Interrogatories included contention interrogatories directed at the factual and legal bases for Lumos's affirmative defenses and counterclaims. The interrogatories at issue include Interrogatory Nos. 1 through 8, which sought the following information:

(a) Interrogatory Nos. 1 through 4 requested that Lumos identify, for each asserted claim of each patent-in-suit, every claim element that Lumos contends is absent from or not practiced by each accused product, together with the factual and technical basis for each such contention (i.e., element-by-element non-infringement contentions);

(b) Interrogatory Nos. 5 and 6 requested that Lumos identify each item of prior art — including patents, patent applications, printed publications, prior public uses, offers for sale, and any other prior art under 35 U.S.C. § 102 — on which Lumos intends to rely in support of its invalidity counterclaims under 35 U.S.C. §§ 102 and 103, together with a description of how each prior art reference anticipates or renders obvious each asserted claim;

(c) Interrogatory No. 7 requested that Lumos identify the factual and legal bases for any invalidity defense under 35 U.S.C. § 112, including any contentions of indefiniteness, lack of written description, or lack of enablement; and

(d) Interrogatory No. 8 requested that Lumos identify all prior art references (including publications, patents, products, and other public disclosures) that Lumos intends to rely upon in support of any invalidity defense, organized by patent and by statutory basis.

B. Nature of Deficiency

Lumos's responses to Interrogatory Nos. 1 through 8 are substantively deficient. Rather than providing the substantive factual and technical information sought by these interrogatories, Lumos's responses merely incorporated by reference: (i) Lumos's Answer, Affirmative Defenses, and Counterclaims (filed July 29, 2022, Dkt. No. 22); and (ii) Lumos's Preliminary Claim Construction Contentions (served September 12, 2022). After these incorporations by reference, Lumos's responses stated generically that "Defendant's investigation is ongoing and Defendant reserves the right to supplement this response." No additional factual detail was provided.

These responses are inadequate for several reasons. First, the Answer and Counterclaims contain only bare legal conclusions — e.g., that the accused products "do not infringe" the patents-in-suit and that the asserted claims are "invalid" — without any factual support or element-by-element analysis. Second, the Preliminary Claim Construction Contentions address the parties' disputes regarding the construction of claim terms, not the factual bases for non-infringement or invalidity. Third, Lumos's responses do not identify specific claim elements that Lumos contends are absent from its accused products, do not identify specific prior art references beyond the handful listed in its Counterclaims, and do not provide a claim-by-claim, element-by-element non-infringement position for either accused product.

OWS recognizes that, in certain circumstances, a party's responses to contention interrogatories may properly be deferred in whole or in part until after claim construction. However, Lumos's responses are deficient even under that deferral standard. Even prior to claim construction, a responding party is obligated to provide a substantive factual narrative setting forth the bases for its contentions, at least at a reasonable level of specificity, rather than resting on bare legal conclusions and incorporations by reference. See Verigy US, Inc. v. Mentor Graphics Corp., No. 10-cv-4591-BLF, 2011 WL 5079530, at *2 (N.D. Cal. Oct. 26, 2011) (ordering supplementation of contention interrogatory responses that merely incorporated by reference prior pleadings). Lumos has had ample time to develop at least preliminary non-infringement and invalidity contentions, and its complete failure to provide any substantive response is prejudicial to OWS's ability to prepare for fact discovery, depositions, and expert reports.

C. Relief Requested

OWS requests that Lumos provide supplemental interrogatory responses as follows:

(a) Non-infringement contentions: Supplemental responses to Interrogatory Nos. 1 through 4 providing element-by-element non-infringement contentions for each asserted claim of each patent-in-suit, as applied to each accused product (the LumosBridge 800G and the LumosEdge 400ZR+). For each claim element that Lumos contends is not practiced by the accused product, Lumos should identify the specific element at issue and describe the factual and technical basis for its non-infringement contention.

(b) Invalidity contentions: Supplemental responses to Interrogatory Nos. 5 through 8 identifying all prior art references — including patents, patent applications, printed publications, prior public uses, prior public knowledge, offers for sale, and any other prior art categories under 35 U.S.C. § 102 — on which Lumos intends to rely in support of its invalidity counterclaims. For each prior art reference, Lumos should identify: (i) the specific asserted claims that are challenged; (ii) the statutory basis for the invalidity challenge (i.e., § 102(a)(1), § 102(a)(2), § 103, and/or § 112); and (iii) a description, at least at a preliminary level, of how the reference anticipates or, in combination with other references, renders obvious the challenged claims.

OWS is aware that the following prior art references have been identified by Lumos in the claim construction proceedings and in its Counterclaims: (i) U.S. Patent No. 9,456,012 to Tanaka ("the Tanaka Patent"); (ii) Chen & Liu, "Efficient Coupling Schemes for Silicon-Based Photonic Integrated Circuits," Journal of Lightwave Technology, Vol. 34, No. 12, pp. 2945–2953 (June 2016) (the "Chen & Liu 2016 Article"); (iii) European Patent Application Publication No. EP 3,234,567 A1 to Nordlicht ("the Nordlicht Publication"); and (iv) Iyer & Patel, "High-Speed Driver Architectures for Silicon Photonic Mach-Zehnder Modulators," IEEE Journal of Solid-State Circuits, Vol. 53, No. 9, pp. 2620–2632 (September 2018) (the "Iyer & Patel 2018 Article"). OWS requests that Lumos confirm whether these are the only prior art references on which it intends to rely or whether additional references will be asserted, and that Lumos provide the claim-by-claim and element-by-element analysis requested above for all such references.

Supplementation should be provided within fourteen (14) days of the date of this letter.

VIII. Deficiency Category 6: Documents Relating to Lumos's Knowledge of OWS's Patents

A. Specific Requests at Issue

OWS's First Set of Requests for Production included requests directed at documents and communications reflecting Lumos's awareness of, analysis of, consideration of, or opinions regarding OWS's patents-in-suit. The requests at issue include RFP Nos. 76, 77, 78, 79, 80, 81, and 82, which sought, among other things:

(a) All documents and communications relating to Lumos's awareness of or knowledge of OWS's patents-in-suit, including but not limited to the '567 Patent, the '234 Patent, the '678 Patent, and the '890 Patent, at any time prior to or after the filing of this action;

(b) All documents and communications relating to the cease-and-desist letter sent by OWS to Lumos on March 15, 2022, including internal Lumos communications discussing or responding to the letter;

(c) All analyses, memoranda, opinions, or assessments prepared by or for Lumos regarding the scope, validity, or enforceability of OWS's patents-in-suit;

(d) All documents and communications reflecting any decisions by Lumos management or its Board of Directors regarding OWS's patents or the risk of patent infringement; and

(e) All documents and communications regarding any design-around efforts or considerations relating to OWS's patents.

These requests are directly relevant to OWS's willfulness allegations and its potential entitlement to enhanced damages under 35 U.S.C. § 284 as construed in Halo Electronics, Inc. v. Pulse Electronics, Inc., 579 U.S. 93 (2016). Evidence of Lumos's pre-suit knowledge of OWS's patents, its internal analysis of infringement risk, and its decision to continue manufacturing and selling the accused products notwithstanding that knowledge is highly probative of whether Lumos's infringement was willful. These documents are also relevant to the pre-suit damages period — Q1 and Q2 2022, during which Lumos generated approximately $62.3 million in accused product revenue — and to the question of when Lumos first became aware of OWS's patent rights.

B. Nature of Deficiency

Lumos's production in response to these requests was grossly deficient. The only documents produced were: (i) the March 15, 2022 cease-and-desist letter from OWS's in-house counsel to Lumos's General Counsel; and (ii) Lumos's April 4, 2022 response letter denying infringement and asserting invalidity. These two letters were already in OWS's possession and do not constitute a meaningful response to the breadth of the requests.

No internal Lumos communications — whether email, instant message, memorandum, or other form — discussing or analyzing OWS's patents were produced. No internal analysis memoranda or technical assessments were produced. No board or management presentations addressing OWS's patent portfolio or the infringement risk were produced. No documents reflecting any design-around considerations were produced. It is not credible that a publicly traded semiconductor company that received a detailed cease-and-desist letter identifying four patents and two accused products, and that subsequently retained outside patent litigation counsel and prepared a formal response letter denying infringement, generated no internal documents or communications beyond the two letters that were produced.

In its responses to RFP Nos. 76 through 82, Lumos stated that it was withholding certain responsive documents on the basis of attorney-client privilege and/or work product protection. However, Lumos has not produced a privilege log that complies with the requirements of Federal Rule of Civil Procedure 26(b)(5)(A), which provides that when a party withholds information on the basis of privilege, the party "must: (i) expressly make the claim; and (ii) describe the nature of the documents, communications, or tangible things not produced or disclosed — and do so in a manner that, without revealing information itself privileged or protected, will enable other parties to assess the claim." The limited privilege log produced by Lumos on December 21, 2022 contains generic entries that do not identify the date, author, recipient(s), subject matter, or specific privilege asserted for each withheld document, as required by Rule 26(b)(5)(A) and the applicable case law. See, e.g., In re Grand Jury Investigation, 974 F.2d 1068, 1071 (9th Cir. 1992); Clarke v. Am. Commerce Nat'l Bank, 974 F.2d 127, 129 (9th Cir. 1992).

Moreover, OWS notes that to the extent Lumos has asserted or intends to assert an advice-of-counsel defense to OWS's willfulness allegations, any privilege over opinion letters, infringement analyses, or related attorney-client communications may be deemed waived. See In re EchoStar Commc'ns Corp., 448 F.3d 1294, 1299 (Fed. Cir. 2006). OWS reserves all rights to challenge any privilege claims and to seek in camera review if necessary.

C. Relief Requested

OWS requests the following:

(a) Non-privileged documents: Production of all non-privileged documents responsive to RFP Nos. 76 through 82, including all internal communications, memoranda, presentations, and analyses discussing or relating to OWS's patents-in-suit, OWS's cease-and-desist letter, the risk of infringement, and any design-around efforts or considerations.

(b) Privilege log: Production of a privilege log compliant with Federal Rule of Civil Procedure 26(b)(5)(A) for all documents withheld on the basis of attorney-client privilege or work product protection. The privilege log must identify, for each withheld document: (i) the date of the document or communication; (ii) the author(s); (iii) the recipient(s) and any persons copied; (iv) a description of the subject matter sufficient to assess the privilege claim without disclosing privileged information; and (v) the specific privilege asserted (attorney-client privilege, attorney work product, or both).

OWS requests that this production and the compliant privilege log be provided within fourteen (14) days of the date of this letter.

IX. Summary of Deficiencies and Deadline for Supplementation

For the convenience of all parties, OWS summarizes below the six categories of deficiencies identified in this letter and the corresponding relief requested:

1. Technical Design Documents — LumosBridge™ 800G Optical Engine. Production of all responsive internal design documents, including photonic circuit layout files, process integration documents, epitaxial growth specifications, waveguide coupler design documents, flip-chip bonding specifications, and related engineering documents. (Section III.)

2. Technical Design Documents — LumosEdge™ 400ZR+ Pluggable Transceiver. Production of all responsive internal design documents for the LumosEdge product, including the same categories of documents identified above. (Section IV.)

3. Source Code for Driver Circuit Firmware. Agreement on a source code inspection protocol and inspection within twenty-one (21) days, or alternatively, production of relevant source code on a secure, encrypted medium under Highly Confidential — Attorneys' Eyes Only designation. (Section V.)

4. Revenue Breakdowns by Product Configuration. Supplemental interrogatory responses and document production providing accused product revenue data broken down by product line, product configuration/SKU, customer, quarter, and geographic region, for the period from Q3 2021 through Q4 2022 (and any available Q1 2023 data). (Section VI.)

5. Contention Interrogatory Responses (Non-Infringement and Invalidity). Supplemental interrogatory responses providing element-by-element non-infringement contentions for each asserted claim and each accused product, and identification of all prior art references relied upon for invalidity, with claim-by-claim charts and identification of statutory bases. (Section VII.)

6. Documents Relating to Lumos's Knowledge of OWS's Patents and Associated Privilege Log. Production of all non-privileged documents relating to Lumos's awareness of and analysis of OWS's patents, and production of a compliant privilege log for all documents withheld on privilege grounds. (Section VIII.)

OWS requests that supplemental production and supplemental interrogatory responses for all six categories be provided within fourteen (14) days of the date of this letter — that is, by no later than February 1, 2023. For the source code inspection specifically, OWS requests that the parties agree on an inspection protocol within fourteen (14) days and that the inspection itself take place within twenty-one (21) days (by February 8, 2023).

In addition, OWS requests that BHS make counsel available for a telephonic meet-and-confer conference within seven (7) days of the date of this letter to discuss these deficiencies and to attempt to reach agreement on a supplementation schedule and any disputed scope issues. We propose January 24 or 25, 2023, at a time convenient for your team. Please advise of your availability.

X. Reservation of Rights

OWS expressly reserves all rights and remedies available under the Federal Rules of Civil Procedure, the Northern District of California Local Rules, and the Patent Local Rules to seek a motion to compel if the deficiencies identified in this letter are not adequately and timely addressed. In the event that OWS is compelled to file a motion to compel, OWS will seek recovery of its reasonable expenses, including attorneys' fees, incurred in connection with such motion, as provided by Federal Rule of Civil Procedure 37(a)(5)(A).

This letter constitutes a good-faith effort to satisfy the meet-and-confer requirements of Federal Rule of Civil Procedure 37(a)(1) and Northern District of California Local Rule 37-1 prior to seeking judicial intervention. OWS is fully prepared to resolve these issues cooperatively if Lumos engages in good faith. However, if the parties are unable to resolve these discovery disputes through the meet-and-confer process, OWS intends to promptly file a motion to compel and, if warranted, a request for sanctions.

OWS reserves all other rights and remedies, whether at law or in equity, in connection with this action, and nothing in this letter shall be construed as a waiver of any such rights or remedies.

XI. Closing

We sincerely hope that these issues can be resolved cooperatively without the need for judicial intervention. OWS's goal is to obtain the discovery to which it is entitled under the Federal Rules so that both parties can prepare their respective cases on a complete and accurate factual record. We believe that the requests outlined in this letter are reasonable, proportional to the needs of this case, and well within the scope of permissible discovery in a patent infringement action of this magnitude.

We respectfully request that you or Ms. Ashworth contact us at your earliest convenience to schedule a meet-and-confer conference to discuss these issues. I can be reached directly at the contact information below. My colleague Alan Ngo is also available to participate in any meet-and-confer discussions and may be reached at (415) 792-8422 or alan.ngo@calderwoodharkness.com.

We look forward to your prompt response.

Sincerely,

CALDERWOOD & HARKNESS LLP

By: ________

Omar Siddiqui

One Embarcadero Center, 34th Floor San Francisco, CA 94111 Direct: (415) 792-8417

Email: omar.siddiqui@calderwoodharkness.com

Counsel for Plaintiff Optiwave Semiconductor Corp.

cc: Victoria "Tori" Ashworth, Esq. (Brannick Howell & Stein LLP) — via email cc: Alan Ngo, Esq. (Calderwood & Harkness LLP) cc: Sandra Ellison, Esq., Deputy General Counsel (Optiwave Semiconductor Corp.) cc: Theodore "Ted" Marchetti, Vice President of intellectual Property (Optiwave Semiconductor Corp.)

Enclosures: None

This letter references specific Request for Production and Interrogatory numbers by number only. Full copies of OWS's First Set of Requests for Production of Documents (Nos. 1–112) and First Set of Interrogatories (Nos. 1–25) were previously served on Brannick Howell & Stein LLP on November 21, 2022.

CALDERWOOD & HARKNESS LLP Counselors at Law
One Embarcadero Center, 34th Floor San Francisco, California 94111 Telephone: (415) 792-8400 Facsimile: (415) 792-8401 www.calderwoodharkness.com
January 18, 2023
Via Email and U.S. Mail
Daniel Kowalski, Esq. Associate Team Lead, intellectual Property Litigation Group Brannick Howell & Stein LLP 555 California Street, Suite 2800 San Francisco, CA 94104
Re: Optiwave Semiconductor Corp. v. Lumos Photonics, Inc., Case No. 5:22-cv-03417-EJD (N.D. Cal.) — Deficiencies in Defendant's Document Production and Interrogatory Responses; Meet-and-Confer Pursuant to Federal Rule of Civil Procedure 37(a)(1) and N.D. Cal. Local Rule 37-1
Dear Mr. Kowalski:
I. Introduction and Purpose of Letter
This firm represents plaintiff Optiwave Semiconductor Corp. ("OWS" or "Optiwave") in the above-captioned patent infringement action against Lumos Photonics, Inc. ("Lumos"), currently pending before the Honorable Edward J. Torvelis in the United States District Court for the Northern District of California. We write to you in your capacity as Associate Team Lead of Brannick Howell & Stein LLP's ("BHS") intellectual Property Litigation Group and as counsel of record for Lumos in this matter.
This letter constitutes a formal meet-and-confer communication pursuant to Federal Rule of Civil Procedure 37(a)(1) and Northern District of California Local Rule 37-1 regarding material deficiencies that OWS has identified in Lumos's responses to OWS's First Set of Requests for Production of Documents (Nos. 1–112) and OWS's First Set of Interrogatories (Nos. 1–25), both of which were served on Lumos on November 21, 2022. Lumos served its responses and objections to the First Set of Requests for Production on December 21, 2022, and its responses and objections to the First Set of Interrogatories on December 22, 2022. Following a thorough review of those responses, including the documents produced to date on Lumos's document review platform, we have identified a number of material deficiencies that require supplementation and cure.
We write in the spirit of cooperation and with the sincere hope that these issues can be resolved without the need for judicial intervention. To that end, we respectfully request that BHS make counsel available for a meet-and-confer conference within seven (7) days of the date of this letter to discuss the deficiencies outlined herein and to negotiate a reasonable supplementation schedule. In addition, we request that Lumos provide supplemental production and supplemental interrogatory responses within fourteen (14) days of the date of this letter — that is, by no later than February 1, 2023.
At the outset, we note that the Stipulated Protective Order entered by the Court on September 16, 2022 (Dkt. No. 48) provides robust protections for commercially sensitive and proprietary information, including a "Highly Confidential — Attorneys' Eyes Only" designation tier that restricts access to outside litigation counsel and designated experts. The protections afforded by the Stipulated Protective Order should substantially address any confidentiality or trade secret concerns that Lumos may have with respect to the categories of documents and information discussed in this letter. Blanket assertions of confidentiality or trade secret protection, without more, cannot justify the wholesale withholding of documents that are plainly relevant to the claims and defenses in this action.
II. Background on discovery Requests
By way of brief background, OWS served its First Set of Requests for Production of Documents (comprising 112 individual requests) and its First Set of Interrogatories (comprising 25 interrogatories) on November 21, 2022, in accordance with the Case Management Order entered by Judge Torvelis on August 22, 2022 (Dkt. No. 39). Lumos, for its part, served its own First Set of Document Requests (comprising 98 requests) on November 7, 2022. OWS timely served its responses and objections to Lumos's First Set on December 7, 2022, and has produced a substantial volume of responsive documents in accordance with those responses, including detailed claim charts, prosecution histories, and technical documentation relating to OWS's patented technologies.
As the Court and the parties are aware, this action involves the infringement of four United States patents owned by OWS:
• U.S. Patent No. 10,234,567 (the "'567 Patent") — entitled "Integrated Waveguide Coupler for Silicon Photonic Platforms," directed to an adiabatically coupled tapered silicon waveguide structure for efficient optical coupling in silicon photonic integrated circuits;
• U.S. Patent No. 10,891,234 (the "'234 Patent") — entitled "Germanium-on-Silicon Photodetector with Graded Buffer Layer," directed to a high-responsivity germanium photodetector integrated on a silicon substrate using a graded buffer layer having a continuously varying germanium concentration;
• U.S. Patent No. 11,045,678 (the "'678 Patent") — entitled "Multi-Channel Optical Transceiver with Integrated Wavelength Division Multiplexing," directed to a multi-channel optical transceiver monolithically formed on a single silicon die with integrated wavelength division multiplexing (WDM) functionality; and
• U.S. Patent No. 11,312,890 (the "'890 Patent") — entitled "Driver Circuit Architecture for Mach-Zehnder Modulator Systems," directed to a pre-emphasis equalization driver circuit architecture electrically co-integrated with a high-speed silicon photonic Mach-Zehnder modulator on a common substrate.
OWS has accused two primary Lumos products of infringing one or more claims of each of the patents-in-suit: (1) the LumosBridge™ 800G Optical Engine, a silicon photonic optical engine designed for hyperscale data center interconnects, which first shipped commercially in Q1 2022 and carries a unit price in the range of $1,200 to $1,800 depending on configuration; and (2) the LumosEdge™ 400ZR+ Pluggable Transceiver, a coherent pluggable optical transceiver in QSFP-DD form factor designed for metro and edge network applications, which has been in production since Q3 2021 and carries a unit price in the range of $600 to $900 depending on configuration.
The parties are currently engaged in claim construction proceedings. OWS filed its Opening Claim Construction Brief on December 5, 2022 (Dkt. No. 72), proposing constructions for fourteen disputed claim terms across the four patents-in-suit. Lumos filed its Responsive Claim Construction Brief on December 19, 2022 (Dkt. No. 78). The Markman hearing is currently scheduled for January 30, 2023 before Judge Torvelis. OWS acknowledges that certain aspects of the infringement analysis may be refined following the Court's claim construction ruling. However, the outstanding discovery identified in this letter is critical not only for the infringement analysis but also for the broader fact discovery that will proceed in parallel with and following claim construction, including discovery relating to damages, willfulness, and the validity defenses Lumos has asserted in its counterclaims. Delay in obtaining this discovery will prejudice OWS's ability to meet the discovery deadlines established in the Case Management Order.
III. Deficiency Category 1: Technical Design Documents for the LumosBridge™ 800G Optical Engine
A. Specific Requests at Issue
OWS's First Set of Requests for Production included numerous requests directed at the internal design and engineering documentation for the LumosBridge™ 800G Optical Engine, which is one of the two primary accused products in this action. The requests at issue include, without limitation, RFP Nos. 5, 7, 9, 12, 14, 17, 21, 23, 26, 28, 31, and 34, which collectively sought the following categories of documents:
(a) Design specifications and architecture documents for the LumosBridge 800G optical engine, including system-level block diagrams, interface specifications, optical link budget analyses, and design review presentations;
(b) Photonic integrated circuit ("PIC") layout files and associated design rule check ("DRC") reports, including GDS-II or OASIS format layout files for the silicon photonic die;
(c) Waveguide coupler design documents, including taper geometry specifications, coupling efficiency simulation results, and fabrication process specifications — these are directly relevant to the '567 Patent's claimed limitation of an "adiabatically coupled" tapered silicon waveguide structure, and OWS requires these documents to determine whether Lumos's waveguide coupler design practices an adiabatic taper or an alternative coupling geometry;
(d) Germanium photodetector design documents, including buffer layer composition specifications, epitaxial growth recipes, and material characterization data (e.g., X-ray diffraction, secondary ion mass spectrometry, or transmission electron microscopy data characterizing the SiGe buffer layer) — these are directly relevant to the '234 Patent's claimed limitation of a "graded buffer layer having a continuously varying germanium concentration," and OWS requires these documents to assess whether Lumos's buffer layer uses a continuously graded or step-graded germanium composition profile;
(e) Documents relating to the micro-transfer-printing process for III-V gain elements bonded to the silicon PIC, including process flow documents, alignment tolerances, and bonding specifications — these are relevant to the '678 Patent's claimed limitation requiring the transceiver to be "monolithically formed on a single silicon die," and OWS requires these documents to evaluate whether Lumos's heterogeneous integration approach satisfies or avoids this limitation; and
(f) Driver circuit integration documents, including flip-chip bonding specifications for the CMOS driver die, copper pillar micro-bump design specifications, and electrical interconnect characterization data — these are relevant to the '890 Patent's claimed "co-integrated" limitation, and OWS requires these documents to evaluate the physical integration architecture between the driver circuit die and the silicon photonic modulator die in the LumosBridge 800G product.
B. Nature of Deficiency
Lumos's production in response to these requests is materially deficient. The documents produced to date consist exclusively of marketing datasheets, publicly available product briefs and application notes, and high-level functional block diagrams — all of which are already publicly available on Lumos's website and in its investor presentations. These documents contain no meaningful technical detail regarding the internal design of the LumosBridge 800G and are wholly inadequate for the purpose of conducting an infringement analysis.
Specifically, Lumos has not produced any of the following categories of responsive documents that unquestionably exist for a product that has been in commercial production since Q1 2022:
• Internal engineering design documents, including design specifications, design review presentations (e.g., PDR, CDR), and engineering change orders;
• Detailed photonic circuit layout files (GDS-II or equivalent);
• Process flow documents describing the silicon photonic fabrication process;
• Epitaxial layer stackup specifications and growth recipes for the germanium photodetector and SiGe buffer layers;
• Material characterization and metrology data for the photodetector structures;
• Integration methodology documents describing the micro-transfer-printing process and the flip-chip bonding process; and
• Simulation and modeling reports for the waveguide coupler, photodetector, modulator, and driver circuit subsystems.
In its responses to the relevant RFPs, Lumos interposed boilerplate objections asserting that the requests were "overbroad," "unduly burdensome," and sought "trade secrets and proprietary information." These objections are insufficient under the Federal Rules. Lumos did not identify with any specificity which documents were being withheld on the basis of these objections, did not explain the basis for the overbreadth or burden claims, and did not propose any narrowing modifications that might address its concerns while still providing OWS with the discovery to which it is entitled. A party resisting discovery on grounds of overbreadth or burden bears the burden of demonstrating that the discovery sought is disproportionate to the needs of the case. See Fed. R. Civ. P. 26(b)(1); Carr v. Brightmoor Indemnity Co., 312 F.R.D. 459, 468 (N.D. Tex. 2015). Lumos has made no such showing.
As to trade secret concerns, we reiterate that the Stipulated Protective Order entered by the Court on September 16, 2022, provides a Highly Confidential — Attorneys' Eyes Only designation tier that restricts access to outside litigation counsel, designated experts, and their support staff. This designation is specifically designed to accommodate the production of commercially sensitive technical documents such as the ones at issue here. The existence of the Protective Order eliminates any legitimate basis for withholding responsive design documents on trade secret grounds. See Adidas Am., Inc. v. TRB Acquisitions LLC, No. 15-cv-02113-KAW, 2016 WL 1637473, at *3 (N.D. Cal. Apr. 26, 2016) (ordering production of trade secret documents under protective order in patent case).
The importance of these documents cannot be overstated. The LumosBridge 800G is a primary accused product that has been generating substantial commercial revenue for Lumos since its launch in Q1 2022, with unit prices ranging from $1,200 to $1,800. Detailed internal technical documents are essential to OWS's infringement analysis under each of the four patents-in-suit. OWS's technical expert, Dr. Harold Whitfield of Whitfield Technical Consulting Group, Inc. (retained in August 2022), cannot complete his infringement analysis based solely on marketing materials and high-level block diagrams that omit the precise technical details necessary to evaluate whether the accused product practices the claimed limitations.
By way of specific example, and without limitation, OWS requires documents sufficient to determine:
(a) Whether Lumos's waveguide coupler in the LumosBridge 800G uses a segmented (non-continuous) taper with discrete coupling sections — as Lumos may contend in its non-infringement defense with respect to the '567 Patent — versus a continuous adiabatic taper as claimed in the '567 Patent. The taper geometry specifications, coupling simulation data, and fabrication process documents will be critical to resolving this issue.
(b) The germanium concentration profile in the SiGe buffer layers of the germanium photodetector. Based on publicly available technical conference presentations by Lumos engineers (including Dr. Mei-Ling Zhao's presentation at the 2022 Optical Fiber Communication Conference), OWS understands that the LumosBridge 800G photodetector may use a step-graded buffer with four discrete composition steps at germanium fractions of approximately 0.25, 0.50, 0.75, and 1.0, rather than a continuously varying germanium concentration as claimed in the '234 Patent. The epitaxial growth recipes, material characterization data, and process specifications will be essential to evaluating this issue and to assessing whether Lumos's step-graded approach falls within or outside the scope of the '234 Patent's claims under the doctrine of equivalents.
(c) The specifics of the micro-transfer-printed III-V gain element bonding process used to integrate laser gain elements onto the silicon PIC in the LumosBridge 800G product, which is relevant to the '678 Patent's "monolithically formed on a single silicon die" limitation. OWS requires process flow documents, bonding specifications, and integration methodology documents to evaluate whether Lumos's heterogeneous integration approach satisfies the "monolithically formed" limitation.
(d) The flip-chip bonding architecture between the separate CMOS driver die and the silicon photonic modulator die in the LumosBridge 800G product. The '890 Patent claims a driver circuit "co-integrated" with the modulator, and the physical integration architecture — including the copper pillar micro-bump specifications, die-to-die interconnect parasitics, and signal integrity characteristics — is critical to the infringement analysis under the '890 Patent.
C. Relief Requested
OWS requests that Lumos produce all responsive internal design documents for the LumosBridge™ 800G Optical Engine, including but not limited to: photonic circuit layout files (in native GDS-II, OASIS, or equivalent format); design specifications and architecture documents; process integration and process flow documents; epitaxial growth specifications and material characterization data; waveguide coupler design and simulation documents; photodetector design documents; micro-transfer-printing process documents; flip-chip bonding process and copper pillar micro-bump design documents; driver circuit integration documents; design review presentations; and engineering change orders. Lumos may designate any or all such documents as "Highly Confidential — Attorneys' Eyes Only" under the Stipulated Protective Order. OWS requests that this production be completed within fourteen (14) days of the date of this letter.
IV. Deficiency Category 2: Technical Design Documents for the LumosEdge™ 400ZR+ Pluggable Transceiver
A. Specific Requests at Issue
OWS's First Set of Requests for Production also included requests specifically directed at the internal design and engineering documentation for the second accused product, the LumosEdge™ 400ZR+ Pluggable Transceiver. The requests at issue include RFP Nos. 6, 8, 10, 13, 15, 18, 22, 24, 27, 29, 32, and 35, which sought the following categories of documents:
(a) QSFP-DD module design specifications, including mechanical, thermal, and electrical design documents for the pluggable transceiver module;
(b) Silicon photonics engine design documents for the photonic integrated circuit within the pluggable module, including PIC layout files, process flow documents, and design review presentations;
(c) Waveguide coupling architecture documents, including taper geometry specifications and coupling efficiency data relevant to the '567 Patent;
(d) Photodetector design documents, including germanium photodetector and SiGe buffer layer specifications relevant to the '234 Patent;
(e) Multi-channel optical transceiver and WDM integration documents relevant to the '678 Patent; and
(f) Modulator driver circuit architecture and integration approach documents, including the physical integration of the driver die with the silicon photonic die, relevant to the '890 Patent.
B. Nature of Deficiency
Lumos's production in response to these requests suffers from the same fundamental deficiency identified with respect to the LumosBridge 800G above. Lumos has produced only public-facing product documentation — datasheets, product briefs, and high-level specifications — without producing any internal design files, engineering change orders, design review presentations, manufacturing process documents, or any of the other categories of internal engineering documents that are plainly responsive to these requests and that must exist for a product that has been in commercial production since Q3 2021.
The LumosEdge™ 400ZR+ is a separately accused product that has been generating substantial revenue for Lumos since its commercial launch in Q3 2021. With unit prices in the $600 to $900 range, the LumosEdge product line represents a significant portion of Lumos's accused product revenue. The LumosEdge employs a different form factor (QSFP-DD pluggable) and may employ different internal design choices compared to the LumosBridge 800G optical engine, which means that a separate and independent infringement analysis is required for this product. OWS cannot conduct that analysis based on marketing materials alone.
Lumos's objections to these requests mirrored the blanket objections interposed in response to the LumosBridge-related requests: assertions of overbreadth, undue burden, and trade secret protection, without any specificity as to which documents are being withheld or why. These objections fail to comply with the requirements of Federal Rule of Civil Procedure 34(b)(2)(B), which mandates that objections "state with specificity the grounds for objecting to the request, including the reasons" and further requires that an objection "state whether any responsive materials are being withheld on the basis of that objection." Fed. R. Civ. P. 34(b)(2)(C). Lumos's responses do not satisfy this standard, and the blanket objections should be deemed waived to the extent they are not accompanied by the specificity required by the Rules. See Burlington N. & Santa Fe Ry. Co. v. U.S. Dist. Court for the Dist. of Mont., 408 F.3d 1142, 1149 (9th Cir. 2005).
C. Relief Requested
OWS requests that Lumos produce the full universe of internal engineering and design documents for the LumosEdge™ 400ZR+ Pluggable Transceiver, including the same categories of documents identified in Section III.C above as applied to the LumosEdge product. As with the LumosBridge documents, Lumos may designate any or all such documents as "Highly Confidential — Attorneys' Eyes Only" under the Stipulated Protective Order. OWS requests that this production be completed within fourteen (14) days of the date of this letter.
V. Deficiency Category 3: Source Code for Driver Circuit Firmware
A. Specific Requests at Issue
OWS's First Set of Requests for Production included requests directed at source code, firmware, and embedded software for the driver circuits used in both the LumosBridge 800G Optical Engine and the LumosEdge 400ZR+ Pluggable Transceiver. The requests at issue include RFP Nos. 38, 39, 41, 42, and 44, which collectively sought all source code, firmware, embedded software, and related documentation (including version control histories, change logs, and design documentation) for the driver circuit subsystems of the accused products.
These requests are directly relevant to the '890 Patent, which is directed to a driver circuit architecture for high-speed silicon photonic Mach-Zehnder modulators. Among the asserted claims of the '890 Patent, Claims 1, 5, 8, and 13 each recite, in relevant part, a "pre-emphasis equalization stage electrically co-integrated with the modulator on a common substrate." The pre-emphasis equalization function in the accused products is implemented at least in part through firmware executing on the driver circuit ASIC or DSP. The firmware that controls the pre-emphasis equalization algorithm — including the tap coefficients, adaptation logic, and signal conditioning parameters — is therefore directly relevant to OWS's infringement analysis under the '890 Patent. Without access to the source code, OWS's technical expert, Dr. Whitfield, cannot fully evaluate how the pre-emphasis equalization is implemented in the accused products or whether the firmware-controlled equalization stage satisfies the "co-integrated" limitation of the asserted claims.
B. Nature of Deficiency
Lumos objected to the production of source code in its entirety, categorically refusing to produce any source code or firmware for the driver circuit subsystems. Lumos's objections cited trade secret protection and proportionality concerns under Rule 26(b)(1), asserting that the source code constitutes "highly sensitive proprietary trade secrets" and that production would impose "undue burden" on Lumos.
These objections are without merit. First, the source code at issue is directly relevant to the infringement analysis under the '890 Patent, and Lumos has not articulated any basis for contending otherwise. The relevance of the source code is not in dispute. Second, Lumos did not offer any compromise or alternative accommodation in its objections — no source code inspection protocol, no stand-alone secure room review, no source code escrow arrangement, and no proposal for production of limited relevant portions of the codebase. A wholesale refusal to produce source code, without any attempt to propose a reasonable accommodation, is inconsistent with the cooperation obligations imposed by the Federal Rules and the Northern District's Patent Local Rules.
Third, we have reviewed Lumos's privilege log (to the extent one was produced — as discussed in Section VIII below, the privilege log itself is deficient), and no entry on the privilege log identifies source code as being withheld on the basis of attorney-client privilege or work product protection. Lumos's objection is therefore based solely on relevance, burden, and trade secret grounds — not privilege. The trade secret concern, as discussed above, is fully addressed by the Stipulated Protective Order's Highly Confidential — Attorneys' Eyes Only designation tier.
Source code inspection is routine in patent infringement cases involving electronic circuits, firmware, and software-controlled functionality. Courts in this District and elsewhere have repeatedly ordered the production of or access to source code in patent cases, subject to appropriate protective order provisions. See, e.g., Ridgeline Industries Am., Inc. v. Stonefield & Co., No. 10-cv-03561-WHA, 2011 WL 3794892 (N.D. Cal. Aug. 26, 2011); Camberwell & Co. v. Northgate & Co. Elecs. Co., No. 11-cv-01846-LHK, 2012 WL 1067548 (N.D. Cal. Mar. 27, 2012). There is no basis for Lumos's categorical refusal to provide any access to the relevant source code.
OWS's designated technical expert, Dr. Harold Whitfield of Whitfield Technical Consulting Group, Inc. (retained August 2022), requires access to the driver circuit firmware source code to complete his infringement analysis with respect to the '890 Patent. Dr. Whitfield has extensive experience in silicon photonic circuit design and driver circuit architecture, including over twenty-five years of experience in the semiconductor industry and prior service as an expert in numerous patent infringement cases involving source code review. Dr. Whitfield is prepared to review the source code under the most restrictive protections available under the Stipulated Protective Order and under any additional source code inspection protocol that the parties may agree upon.
C. Proposed Source Code Inspection Protocol
In the interest of addressing Lumos's stated concerns regarding trade secret protection, OWS proposes the following source code inspection protocol as a reasonable accommodation:
1. Location: The inspection shall take place at a Lumos facility, at Lumos's election: either the Santa Clara office located at 4750 Great America Parkway, Suite 320, Santa Clara, CA 95054, or the Hillsboro, Oregon fabrication facility located at 3200 NE Shute Road, Hillsboro, OR 97124.
2. Access: Inspection shall be limited to OWS's outside litigation counsel (specifically, attorneys at Calderwood & Harkness LLP who are admitted to the bar of this Court and who have signed the Stipulated Protective Order) and OWS's designated technical expert, Dr. Harold Whitfield, each of whom shall have executed the Stipulated Protective Order's acknowledgment and agreement to be bound.
3. Designation: All source code materials made available for inspection shall be designated "Highly Confidential — Attorneys' Eyes Only" under the Stipulated Protective Order.
4. No Copying: No electronic or photographic copying of source code shall be permitted. Inspecting parties may take handwritten notes during the inspection, and such notes shall be subject to the Stipulated Protective Order's Highly Confidential — Attorneys' Eyes Only restrictions.
5. Duration: OWS proposes an initial inspection period of up to three (3) business days, with the parties to confer regarding any need for additional inspection time.
6. Timing: OWS proposes that the inspection occur within twenty-one (21) days of the date of this letter (i.e., by February 8, 2023), with specific dates to be coordinated between counsel.
This proposed protocol is consistent with source code inspection protocols routinely employed in patent cases in this District and provides robust protections against any unauthorized use or disclosure of Lumos's proprietary code.
D. Relief Requested
OWS requests that the parties agree upon a source code inspection protocol, based on the framework proposed above or a mutually agreeable alternative, within fourteen (14) days of the date of this letter. OWS further requests that the source code inspection itself take place within twenty-one (21) days of the date of this letter. In the alternative, if Lumos prefers to produce the relevant portions of the driver circuit firmware source code rather than host an on-site inspection, OWS will accept production of the relevant source code on a secure, encrypted medium (e.g., an encrypted hard drive or secure virtual data room) under the Highly Confidential — Attorneys' Eyes Only designation of the Stipulated Protective Order.
VI. Deficiency Category 4: Revenue Breakdowns by Product Configuration
A. Specific Requests at Issue
OWS's First Set of Requests for Production and First Set of Interrogatories included requests directed at revenue and financial data for the accused products. The requests at issue include RFP Nos. 52, 54, 56, 58, 60, and 62 and Interrogatory Nos. 14, 15, 16, and 17, which collectively sought revenue data for the LumosBridge 800G and LumosEdge 400ZR+ products broken down by the following categories:
(a) Product line — i.e., revenue attributable to the LumosBridge™ 800G Optical Engine versus revenue attributable to the LumosEdge™ 400ZR+ Pluggable Transceiver;
(b) Product configuration / SKU — i.e., revenue attributable to each individual product configuration or stock keeping unit within each product line, including different data rate, reach, and interface configurations;
(c) Customer — i.e., revenue attributable to each customer purchasing the accused products;
(d) Geographic region — i.e., revenue attributable to sales in specific geographic regions, with a specific focus on sales within or shipped to or from the Northern District of California; and
(e) Quarter — i.e., revenue data on a quarterly basis from Q1 2021 through Q4 2022 (and any available data for Q1 2023).
These data are directly relevant to OWS's damages analysis. OWS's claimed damages exceed $75 million based on a reasonable royalty theory, calculated by applying an estimated 7.5% royalty rate to the accused products' revenue base, with the potential for enhanced damages based on willfulness. According to Lumos's most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission, the combined revenue from the accused product lines for calendar year 2022 was approximately $148.6 million, with approximately $62.3 million attributable to Q1 and Q2 2022 — the pre-suit damages period before this action was filed on June 17, 2022. OWS's designated damages expert, Dr. Lawrence Kessler of Apex Claim Analytics LLC (retained October 2022), requires granular, product-level and customer-level revenue data in order to perform a reliable Georgia-Pacific reasonable royalty analysis and to quantify OWS's damages with the specificity required by Uniloc USA, Inc. v. Kestrel Partners LLC, 632 F.3d 1292 (Fed. Cir. 2011), and its progeny.
B. Nature of Deficiency
Lumos's document production and interrogatory responses regarding revenue data are substantively deficient. In its document production, Lumos produced only the aggregate revenue figures that are publicly available from its Form 10-K filing and its quarterly reports on Form 10-Q. Lumos Photonics is a publicly traded company listed on the Nasdaq Stock Market under the ticker symbol LMPH, and OWS already had access to the same aggregate financial data through Lumos's public filings. No additional internal financial data — no breakdown by individual accused product, no breakdown by product configuration or SKU, no customer-level data, and no geographic breakdown — was produced.
Lumos's interrogatory responses regarding revenue were equally deficient. In response to Interrogatory Nos. 14 through 17, Lumos merely cross-referenced its publicly filed 10-K and 10-Q reports and stated that "further detail regarding revenue by product line, configuration, customer, and geography is proprietary and competitively sensitive business information" that Lumos declined to produce. This is not an adequate interrogatory response under Federal Rule of Civil Procedure 33(b)(3), which requires that each interrogatory be answered "separately and fully in writing under oath." An interrogatory response that simply directs the propounding party to publicly available documents without providing any additional substantive information does not satisfy this standard. See Pulsecard, Inc. v. Discover Card Servs., Inc., 168 F.R.D. 295, 310 (D. Kan. 1996).
Aggregate, publicly available revenue data is manifestly insufficient for a meaningful damages analysis in a patent infringement case of this magnitude. Configuration-level pricing data is critical given the significant price ranges within each product line — the LumosBridge 800G ranges from $1,200 to $1,800 per unit and the LumosEdge 400ZR+ ranges from $600 to $900 per unit, meaning that the specific mix of configurations sold has a material impact on the royalty base calculation. Customer-level data is necessary to assess the reasonable royalty base and to evaluate multiple Georgia-Pacific factors, including but not limited to: the commercial relationship between OWS and Lumos (Georgia-Pacific factor 4); the effect of selling the patented specialty or the unpatented product in promoting sales of other products of the licensee (Georgia-Pacific factor 6); the portion of the profit or of the selling price that may be customary in the particular business or in comparable businesses to allow for the use of the invention or analogous inventions (Georgia-Pacific factor 12); and the portion of the realizable profit that should be credited to the invention as distinguished from non-patented elements (Georgia-Pacific factor 13). Geographic data is separately necessary to establish the proper damages base for sales within the jurisdiction.
C. Relief Requested
OWS requests that Lumos provide supplemental interrogatory responses and supplemental document production providing accused product revenue data broken down by: (i) product line (LumosBridge 800G vs. LumosEdge 400ZR+); (ii) product configuration/SKU; (iii) customer; (iv) quarter; and (v) geographic region (including sales within the Northern District of California). This data should cover the period from Q3 2021 (when the LumosEdge 400ZR+ entered production) through Q4 2022, and any available data for Q1 2023. Lumos may designate all such financial data as "Highly Confidential — Attorneys' Eyes Only" under the Stipulated Protective Order. OWS requests that this supplemental production and these supplemental responses be provided within fourteen (14) days of the date of this letter.
VII. Deficiency Category 5: Interrogatory Responses Regarding Non-Infringement and Invalidity Contentions
A. Specific Interrogatories at Issue
OWS's First Set of Interrogatories included contention interrogatories directed at the factual and legal bases for Lumos's affirmative defenses and counterclaims. The interrogatories at issue include Interrogatory Nos. 1 through 8, which sought the following information:
(a) Interrogatory Nos. 1 through 4 requested that Lumos identify, for each asserted claim of each patent-in-suit, every claim element that Lumos contends is absent from or not practiced by each accused product, together with the factual and technical basis for each such contention (i.e., element-by-element non-infringement contentions);
(b) Interrogatory Nos. 5 and 6 requested that Lumos identify each item of prior art — including patents, patent applications, printed publications, prior public uses, offers for sale, and any other prior art under 35 U.S.C. § 102 — on which Lumos intends to rely in support of its invalidity counterclaims under 35 U.S.C. §§ 102 and 103, together with a description of how each prior art reference anticipates or renders obvious each asserted claim;
(c) Interrogatory No. 7 requested that Lumos identify the factual and legal bases for any invalidity defense under 35 U.S.C. § 112, including any contentions of indefiniteness, lack of written description, or lack of enablement; and
(d) Interrogatory No. 8 requested that Lumos identify all prior art references (including publications, patents, products, and other public disclosures) that Lumos intends to rely upon in support of any invalidity defense, organized by patent and by statutory basis.
B. Nature of Deficiency
Lumos's responses to Interrogatory Nos. 1 through 8 are substantively deficient. Rather than providing the substantive factual and technical information sought by these interrogatories, Lumos's responses merely incorporated by reference: (i) Lumos's Answer, Affirmative Defenses, and Counterclaims (filed July 29, 2022, Dkt. No. 22); and (ii) Lumos's Preliminary Claim Construction Contentions (served September 12, 2022). After these incorporations by reference, Lumos's responses stated generically that "Defendant's investigation is ongoing and Defendant reserves the right to supplement this response." No additional factual detail was provided.
These responses are inadequate for several reasons. First, the Answer and Counterclaims contain only bare legal conclusions — e.g., that the accused products "do not infringe" the patents-in-suit and that the asserted claims are "invalid" — without any factual support or element-by-element analysis. Second, the Preliminary Claim Construction Contentions address the parties' disputes regarding the construction of claim terms, not the factual bases for non-infringement or invalidity. Third, Lumos's responses do not identify specific claim elements that Lumos contends are absent from its accused products, do not identify specific prior art references beyond the handful listed in its Counterclaims, and do not provide a claim-by-claim, element-by-element non-infringement position for either accused product.
OWS recognizes that, in certain circumstances, a party's responses to contention interrogatories may properly be deferred in whole or in part until after claim construction. However, Lumos's responses are deficient even under that deferral standard. Even prior to claim construction, a responding party is obligated to provide a substantive factual narrative setting forth the bases for its contentions, at least at a reasonable level of specificity, rather than resting on bare legal conclusions and incorporations by reference. See Verigy US, Inc. v. Mentor Graphics Corp., No. 10-cv-4591-BLF, 2011 WL 5079530, at *2 (N.D. Cal. Oct. 26, 2011) (ordering supplementation of contention interrogatory responses that merely incorporated by reference prior pleadings). Lumos has had ample time to develop at least preliminary non-infringement and invalidity contentions, and its complete failure to provide any substantive response is prejudicial to OWS's ability to prepare for fact discovery, depositions, and expert reports.
C. Relief Requested
OWS requests that Lumos provide supplemental interrogatory responses as follows:
(a) Non-infringement contentions: Supplemental responses to Interrogatory Nos. 1 through 4 providing element-by-element non-infringement contentions for each asserted claim of each patent-in-suit, as applied to each accused product (the LumosBridge 800G and the LumosEdge 400ZR+). For each claim element that Lumos contends is not practiced by the accused product, Lumos should identify the specific element at issue and describe the factual and technical basis for its non-infringement contention.
(b) Invalidity contentions: Supplemental responses to Interrogatory Nos. 5 through 8 identifying all prior art references — including patents, patent applications, printed publications, prior public uses, prior public knowledge, offers for sale, and any other prior art categories under 35 U.S.C. § 102 — on which Lumos intends to rely in support of its invalidity counterclaims. For each prior art reference, Lumos should identify: (i) the specific asserted claims that are challenged; (ii) the statutory basis for the invalidity challenge (i.e., § 102(a)(1), § 102(a)(2), § 103, and/or § 112); and (iii) a description, at least at a preliminary level, of how the reference anticipates or, in combination with other references, renders obvious the challenged claims.
OWS is aware that the following prior art references have been identified by Lumos in the claim construction proceedings and in its Counterclaims: (i) U.S. Patent No. 9,456,012 to Tanaka ("the Tanaka Patent"); (ii) Chen & Liu, "Efficient Coupling Schemes for Silicon-Based Photonic Integrated Circuits," Journal of Lightwave Technology, Vol. 34, No. 12, pp. 2945–2953 (June 2016) (the "Chen & Liu 2016 Article"); (iii) European Patent Application Publication No. EP 3,234,567 A1 to Nordlicht ("the Nordlicht Publication"); and (iv) Iyer & Patel, "High-Speed Driver Architectures for Silicon Photonic Mach-Zehnder Modulators," IEEE Journal of Solid-State Circuits, Vol. 53, No. 9, pp. 2620–2632 (September 2018) (the "Iyer & Patel 2018 Article"). OWS requests that Lumos confirm whether these are the only prior art references on which it intends to rely or whether additional references will be asserted, and that Lumos provide the claim-by-claim and element-by-element analysis requested above for all such references.
Supplementation should be provided within fourteen (14) days of the date of this letter.
VIII. Deficiency Category 6: Documents Relating to Lumos's Knowledge of OWS's Patents
A. Specific Requests at Issue
OWS's First Set of Requests for Production included requests directed at documents and communications reflecting Lumos's awareness of, analysis of, consideration of, or opinions regarding OWS's patents-in-suit. The requests at issue include RFP Nos. 76, 77, 78, 79, 80, 81, and 82, which sought, among other things:
(a) All documents and communications relating to Lumos's awareness of or knowledge of OWS's patents-in-suit, including but not limited to the '567 Patent, the '234 Patent, the '678 Patent, and the '890 Patent, at any time prior to or after the filing of this action;
(b) All documents and communications relating to the cease-and-desist letter sent by OWS to Lumos on March 15, 2022, including internal Lumos communications discussing or responding to the letter;
(c) All analyses, memoranda, opinions, or assessments prepared by or for Lumos regarding the scope, validity, or enforceability of OWS's patents-in-suit;
(d) All documents and communications reflecting any decisions by Lumos management or its Board of Directors regarding OWS's patents or the risk of patent infringement; and
(e) All documents and communications regarding any design-around efforts or considerations relating to OWS's patents.
These requests are directly relevant to OWS's willfulness allegations and its potential entitlement to enhanced damages under 35 U.S.C. § 284 as construed in Halo Electronics, Inc. v. Pulse Electronics, Inc., 579 U.S. 93 (2016). Evidence of Lumos's pre-suit knowledge of OWS's patents, its internal analysis of infringement risk, and its decision to continue manufacturing and selling the accused products notwithstanding that knowledge is highly probative of whether Lumos's infringement was willful. These documents are also relevant to the pre-suit damages period — Q1 and Q2 2022, during which Lumos generated approximately $62.3 million in accused product revenue — and to the question of when Lumos first became aware of OWS's patent rights.
B. Nature of Deficiency
Lumos's production in response to these requests was grossly deficient. The only documents produced were: (i) the March 15, 2022 cease-and-desist letter from OWS's in-house counsel to Lumos's General Counsel; and (ii) Lumos's April 4, 2022 response letter denying infringement and asserting invalidity. These two letters were already in OWS's possession and do not constitute a meaningful response to the breadth of the requests.
No internal Lumos communications — whether email, instant message, memorandum, or other form — discussing or analyzing OWS's patents were produced. No internal analysis memoranda or technical assessments were produced. No board or management presentations addressing OWS's patent portfolio or the infringement risk were produced. No documents reflecting any design-around considerations were produced. It is not credible that a publicly traded semiconductor company that received a detailed cease-and-desist letter identifying four patents and two accused products, and that subsequently retained outside patent litigation counsel and prepared a formal response letter denying infringement, generated no internal documents or communications beyond the two letters that were produced.
In its responses to RFP Nos. 76 through 82, Lumos stated that it was withholding certain responsive documents on the basis of attorney-client privilege and/or work product protection. However, Lumos has not produced a privilege log that complies with the requirements of Federal Rule of Civil Procedure 26(b)(5)(A), which provides that when a party withholds information on the basis of privilege, the party "must: (i) expressly make the claim; and (ii) describe the nature of the documents, communications, or tangible things not produced or disclosed — and do so in a manner that, without revealing information itself privileged or protected, will enable other parties to assess the claim." The limited privilege log produced by Lumos on December 21, 2022 contains generic entries that do not identify the date, author, recipient(s), subject matter, or specific privilege asserted for each withheld document, as required by Rule 26(b)(5)(A) and the applicable case law. See, e.g., In re Grand Jury Investigation, 974 F.2d 1068, 1071 (9th Cir. 1992); Clarke v. Am. Commerce Nat'l Bank, 974 F.2d 127, 129 (9th Cir. 1992).
Moreover, OWS notes that to the extent Lumos has asserted or intends to assert an advice-of-counsel defense to OWS's willfulness allegations, any privilege over opinion letters, infringement analyses, or related attorney-client communications may be deemed waived. See In re EchoStar Commc'ns Corp., 448 F.3d 1294, 1299 (Fed. Cir. 2006). OWS reserves all rights to challenge any privilege claims and to seek in camera review if necessary.
C. Relief Requested
OWS requests the following:
(a) Non-privileged documents: Production of all non-privileged documents responsive to RFP Nos. 76 through 82, including all internal communications, memoranda, presentations, and analyses discussing or relating to OWS's patents-in-suit, OWS's cease-and-desist letter, the risk of infringement, and any design-around efforts or considerations.
(b) Privilege log: Production of a privilege log compliant with Federal Rule of Civil Procedure 26(b)(5)(A) for all documents withheld on the basis of attorney-client privilege or work product protection. The privilege log must identify, for each withheld document: (i) the date of the document or communication; (ii) the author(s); (iii) the recipient(s) and any persons copied; (iv) a description of the subject matter sufficient to assess the privilege claim without disclosing privileged information; and (v) the specific privilege asserted (attorney-client privilege, attorney work product, or both).
OWS requests that this production and the compliant privilege log be provided within fourteen (14) days of the date of this letter.
IX. Summary of Deficiencies and Deadline for Supplementation
For the convenience of all parties, OWS summarizes below the six categories of deficiencies identified in this letter and the corresponding relief requested:
1. Technical Design Documents — LumosBridge™ 800G Optical Engine. Production of all responsive internal design documents, including photonic circuit layout files, process integration documents, epitaxial growth specifications, waveguide coupler design documents, flip-chip bonding specifications, and related engineering documents. (Section III.)
2. Technical Design Documents — LumosEdge™ 400ZR+ Pluggable Transceiver. Production of all responsive internal design documents for the LumosEdge product, including the same categories of documents identified above. (Section IV.)
3. Source Code for Driver Circuit Firmware. Agreement on a source code inspection protocol and inspection within twenty-one (21) days, or alternatively, production of relevant source code on a secure, encrypted medium under Highly Confidential — Attorneys' Eyes Only designation. (Section V.)
4. Revenue Breakdowns by Product Configuration. Supplemental interrogatory responses and document production providing accused product revenue data broken down by product line, product configuration/SKU, customer, quarter, and geographic region, for the period from Q3 2021 through Q4 2022 (and any available Q1 2023 data). (Section VI.)
5. Contention Interrogatory Responses (Non-Infringement and Invalidity). Supplemental interrogatory responses providing element-by-element non-infringement contentions for each asserted claim and each accused product, and identification of all prior art references relied upon for invalidity, with claim-by-claim charts and identification of statutory bases. (Section VII.)
6. Documents Relating to Lumos's Knowledge of OWS's Patents and Associated Privilege Log. Production of all non-privileged documents relating to Lumos's awareness of and analysis of OWS's patents, and production of a compliant privilege log for all documents withheld on privilege grounds. (Section VIII.)
OWS requests that supplemental production and supplemental interrogatory responses for all six categories be provided within fourteen (14) days of the date of this letter — that is, by no later than February 1, 2023. For the source code inspection specifically, OWS requests that the parties agree on an inspection protocol within fourteen (14) days and that the inspection itself take place within twenty-one (21) days (by February 8, 2023).
In addition, OWS requests that BHS make counsel available for a telephonic meet-and-confer conference within seven (7) days of the date of this letter to discuss these deficiencies and to attempt to reach agreement on a supplementation schedule and any disputed scope issues. We propose January 24 or 25, 2023, at a time convenient for your team. Please advise of your availability.
X. Reservation of Rights
OWS expressly reserves all rights and remedies available under the Federal Rules of Civil Procedure, the Northern District of California Local Rules, and the Patent Local Rules to seek a motion to compel if the deficiencies identified in this letter are not adequately and timely addressed. In the event that OWS is compelled to file a motion to compel, OWS will seek recovery of its reasonable expenses, including attorneys' fees, incurred in connection with such motion, as provided by Federal Rule of Civil Procedure 37(a)(5)(A).
This letter constitutes a good-faith effort to satisfy the meet-and-confer requirements of Federal Rule of Civil Procedure 37(a)(1) and Northern District of California Local Rule 37-1 prior to seeking judicial intervention. OWS is fully prepared to resolve these issues cooperatively if Lumos engages in good faith. However, if the parties are unable to resolve these discovery disputes through the meet-and-confer process, OWS intends to promptly file a motion to compel and, if warranted, a request for sanctions.
OWS reserves all other rights and remedies, whether at law or in equity, in connection with this action, and nothing in this letter shall be construed as a waiver of any such rights or remedies.
XI. Closing
We sincerely hope that these issues can be resolved cooperatively without the need for judicial intervention. OWS's goal is to obtain the discovery to which it is entitled under the Federal Rules so that both parties can prepare their respective cases on a complete and accurate factual record. We believe that the requests outlined in this letter are reasonable, proportional to the needs of this case, and well within the scope of permissible discovery in a patent infringement action of this magnitude.
We respectfully request that you or Ms. Ashworth contact us at your earliest convenience to schedule a meet-and-confer conference to discuss these issues. I can be reached directly at the contact information below. My colleague Alan Ngo is also available to participate in any meet-and-confer discussions and may be reached at (415) 792-8422 or alan.ngo@calderwoodharkness.com.
We look forward to your prompt response.
Sincerely,
CALDERWOOD & HARKNESS LLP
By: ________
Omar Siddiqui
One Embarcadero Center, 34th Floor San Francisco, CA 94111 Direct: (415) 792-8417
Email: omar.siddiqui@calderwoodharkness.com
Counsel for Plaintiff Optiwave Semiconductor Corp.
cc: Victoria "Tori" Ashworth, Esq. (Brannick Howell & Stein LLP) — via email cc: Alan Ngo, Esq. (Calderwood & Harkness LLP) cc: Sandra Ellison, Esq., Deputy General Counsel (Optiwave Semiconductor Corp.) cc: Theodore "Ted" Marchetti, Vice President of intellectual Property (Optiwave Semiconductor Corp.)
Enclosures: None
This letter references specific Request for Production and Interrogatory numbers by number only. Full copies of OWS's First Set of Requests for Production of Documents (Nos. 1–112) and First Set of Interrogatories (Nos. 1–25) were previously served on Brannick Howell & Stein LLP on November 21, 2022.

CALDERWOOD & HARKNESS LLP Counselors at Law

CALDERWOOD & HARKNESS LLP

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