MEMORANDUM

MEMORANDUM
PRIVILEGED & CONFIDENTIAL — ATTORNEY WORK PRODUCT
TO: Alan Ngo, Responsible Partner
FROM: Wendy Schultz, Lead Associate; Omar Siddiqui, Working Associate
CC: Marcus Delgado, Billing Partner; James "Jim" Callahan, Local Counsel (Whitmore & Callahan LLP)
DATE: February 28, 2025
RE: Markman Hearing Preparation — Optiwave Semiconductor Corp. v. Lumicore Technologies, Inc., Case No. 2:24-cv-00319-JRG (E.D. Tex.)
HEARING DATE: March 14, 2025, before the Honorable James R. Gilstrap, United States District Judge
PURPOSE: To prepare Alan Ngo for oral argument at the Markman hearing by summarizing each disputed claim term, presenting OWS's positions and fallback constructions, anticipating Lumicore's arguments and likely questions from the Court, and providing recommended responses.
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I. EXECUTIVE SUMMARY
This memorandum provides a comprehensive preparation guide for the upcoming Markman hearing scheduled for March 14, 2025, before Judge James R. Gilstrap in the Eastern District of Texas, marshall Division.
Procedural Posture. Fourteen total disputed claim terms were identified in the Joint Claim Construction Statement filed on October 28, 2024, pursuant to the Court's Scheduling Order. Following subsequent negotiations between counsel, two of those terms — "optical signal" ('847 Patent, Claims 1 and 9) and "silicon waveguide" ('193 Patent, Claims 1 and 10) — were resolved by agreement, with both parties stipulating to plain and ordinary meaning. Accordingly, twelve claim terms remain in dispute and are set for adjudication at the hearing.
Briefing Status. The parties' claim construction briefing is complete. OWS filed its Opening Claim Construction Brief on November 15, 2024. Lumicore, through its counsel at Hawthorne Vega & Cruz LLP (lead partner Catherine "Kate" Rourke), filed its Responsive Claim Construction Brief on December 6, 2024. OWS's Reply Brief was filed on December 20, 2024. By leave of Court granted on January 3, 2025, Lumicore filed a Sur-Reply on January 10, 2025, which addressed three specific terms — "waveguide multiplexer," "integrated on a silicon substrate," and "polarization-diverse grating coupler" — and introduced a supplemental declaration from Dr. Rajiv Sundaram (Pacific Western University). The final Joint Claim Construction Chart was submitted on January 15, 2025, and reflects the parties' final positions on all twelve disputed terms.
Technology Tutorial. Claim construction tutorial submissions are due in February 2025. Our draft tutorial presentation has been prepared in coordination with Dr. Caroline Ashford, Professor of Electrical Engineering and Photonics at the Northfield Institute of Technology, and is currently under final review. The tutorial covers silicon photonics fundamentals, waveguide multiplexing architectures, coherent transceivers and their functional components, thermal management in photonic integrated circuits (PICs), and polarization-diverse grating couplers. We anticipate that the tutorial will be presented either in a separate session or during the opening portion of the Markman hearing, consistent with Judge Gilstrap's customary practice.
Asserted Patents. The four asserted patents at issue in this litigation are:
1.  U.S. Patent No. 10,234,847 (the "'847 Patent") — "Multi-Channel Silicon Photonic Waveguide Multiplexer with Low Insertion Loss," filed September 14, 2016, issued March 19, 2019.
2.  U.S. Patent No. 10,891,193 (the "'193 Patent") — "High-Bandwidth Coherent Optical Transceiver Integrated on Silicon Substrate," filed April 7, 2017, issued January 12, 2021.
3.  U.S. Patent No. 9,678,562 (the "'562 Patent") — "Method for Thermal Management of Photonic Integrated Circuits Using Embedded Micro-Channel Heat Sinks," filed November 22, 2014, issued June 13, 2017 (originally assigned to Solara Optics, Inc.; acquired by OWS via Asset Purchase Agreement dated June 15, 2018, for $34.5 million).
4.  U.S. Patent No. 11,402,015 (the "'015 Patent") — "Polarization-Diverse Grating Coupler for Silicon Photonic Transceivers," filed August 30, 2019, issued August 2, 2022.
Stakes of the Markman Ruling. The claim constructions adopted by the Court will directly and materially impact every aspect of this case going forward. On the infringement side, constructions of the four primary disputed terms — "waveguide multiplexer," "integrated on a silicon substrate," "micro-channel heat sink," and "polarization-diverse grating coupler" — will determine whether OWS can establish literal infringement against Lumicore's three accused product families: the LumiLink 400G-ZR+ (FY23 revenue: approximately $94.8 million), the LumiLink 800G-DR8 (FY23 revenue: approximately $128.4 million), and the LumiEdge 1600G-LR (FY23 revenue: approximately $41.7 million). In addition, the constructions will affect the viability of OWS's doctrine of equivalents contentions on Claims 3 and 7 of the '193 Patent and Claim 12 of the '015 Patent, which are subject to prosecution history estoppel arguments that turn, in part, on the scope of the construed terms. On the validity side, broader constructions expand the universe of potentially invalidating prior art, though our analysis (detailed in Section VI below) concludes that the incremental invalidity risk is manageable because the prior art fails on other claim limitations not at issue in claim construction. Finally, the constructions will shape the overall damages framework for OWS's demand of approximately $210 million, which is based on a reasonable royalty theory calculated across the three accused product families.
Recommendation. We recommend that Alan lead oral argument with the four highest-impact terms (Terms 1–4) in the order of priority set forth in Section VII below, allocating the majority of argument time to those terms while managing the remaining eight terms efficiently. If the Court signals particular interest in a secondary term, Alan should be prepared to pivot and address that term in greater depth. Detailed recommended responses and sound bites for each term are provided below.
II. JUDGE GILSTRAP — BENCH PROFILE AND MARKMAN HEARING TENDENCIES
A. General Approach to Claim Construction
Judge James R. Gilstrap of the Eastern District of Texas is among the most experienced patent trial judges in the country, having presided over hundreds of patent cases and conducted an extraordinary number of Markman hearings during his tenure on the bench. His claim construction methodology is well-established and largely predictable, which provides us with a reliable framework for structuring our arguments.
Primacy of Intrinsic Evidence. Judge Gilstrap strongly favors intrinsic evidence — the claims, the specification, and the prosecution history — over extrinsic evidence such as expert declarations, dictionaries, and treatises. He will reference Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (en banc), as the governing framework for claim construction and will expect counsel to ground every argument in the intrinsic record. While extrinsic evidence is not excluded, it functions in Judge Gilstrap's courtroom as a confirmatory resource rather than a primary basis for construction. Where extrinsic evidence conflicts with intrinsic evidence, the intrinsic evidence will control.
Sensitivity to Reading Out Embodiments. Judge Gilstrap routinely asks pointed questions about whether a proposed construction would have the effect of reading out any disclosed embodiment from the scope of the claims. This is a critical analytical tool for the Court, and any construction that would exclude a described embodiment from the claim scope will face heavy skepticism. Alan should be prepared to demonstrate, for each disputed term, that OWS's proposed construction is consistent with all embodiments disclosed in the specification.
Resistance to Importing Limitations. Judge Gilstrap is typically skeptical of claim constructions that import limitations from the specification into the claims, and he frequently invokes the well-settled principle that claims are not to be limited to preferred embodiments. He will cite the Federal Circuit's repeated admonitions against confusing claim scope with the specific examples disclosed in the specification. This principle is favorable to OWS on several key terms, particularly "waveguide multiplexer" and "polarization-diverse grating coupler," where Lumicore seeks to limit the claims to specific architectures that are described as preferred embodiments.
Enforcement of Clear Disavowal. However, Judge Gilstrap will hold parties to clear disclaimer or disavowal during prosecution. He closely reviews prosecution history amendments, examiner interview summaries, and arguments made to distinguish prior art. Where the applicant made unambiguous representations to the examiner about the scope of a claim term — particularly in the context of overcoming a prior art rejection — Judge Gilstrap will enforce those representations as a limit on claim scope. Our prosecution history analyses for each of the four asserted patents have been prepared with this in mind, and we have identified the specific amendments and arguments that Lumicore is likely to cite. As detailed below, none of the prosecution-history arguments advanced by Lumicore rise to the level of clear disavowal with respect to the terms currently in dispute.
Claim Differentiation. Judge Gilstrap gives meaningful weight to the doctrine of claim differentiation. He has consistently recognized that where a dependent claim adds a specific limitation that would be redundant under a defendant's proposed construction of the independent claim, this creates a presumption that the independent claim is broader than the dependent claim. This is a powerful tool for OWS on Terms 1, 3, 4, and 6.
Practical Impact Questions. Judge Gilstrap frequently asks counsel about the practical impact of each proposed construction on the infringement and validity analyses. This is not an invitation to engage in results-oriented advocacy; rather, the Court uses these questions to assess whether a proposed construction is driven by litigation strategy rather than genuine claim meaning. Counsel should be prepared to address these questions forthrightly, acknowledging the practical consequences of each construction while emphasizing that the construction is dictated by the intrinsic evidence. A response that appears to be tailored to achieve a particular litigation outcome will undermine credibility.
B. Format and Logistics
Hearing Duration and Structure. For a case with twelve disputed claim terms, the hearing will typically last two to four hours. Judge Gilstrap usually allocates equal time to each side, though he retains discretion to adjust the allocation based on the complexity and importance of particular terms. He typically opens with the plaintiff and allows counsel to present each disputed term in sequence, asking clarifying questions throughout the presentation. He may also call on defendant's counsel mid-presentation to address specific points or to present a counterargument before the plaintiff's counsel has completed its full presentation. Alan should not be surprised if Judge Gilstrap interrupts the presentation to pose a question to opposing counsel and then returns to OWS for a response.
Technology Tutorial. Judge Gilstrap frequently uses a technology tutorial as either a separate session or an opening portion of the Markman hearing. Our tutorial submission covers the core technological concepts underlying the asserted patents: silicon photonics fundamentals (waveguide physics, material platforms, integration approaches), waveguide multiplexing (AWGs, Echelle gratings, ring-resonator-based multiplexers), coherent optical transceivers (modulation formats, coherent detection, DSP), thermal management in photonic integrated circuits (heat dissipation challenges, micro-channel cooling, active and passive thermal solutions), and polarization-diverse grating couplers (1D and 2D gratings, polarization handling, coupling efficiency). The tutorial has been prepared in coordination with Dr. Ashford and is designed to provide the Court with a neutral technical foundation without advocating for any particular claim construction.
Key Term Focus. Judge Gilstrap sometimes identifies a "key term" early in the hearing and spends disproportionate time on it, compressing the time available for other terms. Alan should be prepared for the possibility that "waveguide multiplexer" (Term 1) or "integrated on a silicon substrate" (Term 2) consumes a large portion of the argument time. If this occurs, Alan should be ready to efficiently address the remaining terms in abbreviated form, relying on the detailed briefing already submitted.
Courtroom and Local Counsel. The hearing will take place at the E.D. Tex. Marshall Division courthouse. Local counsel Jim Callahan of Whitmore & Callahan LLP (110 North College Avenue, Suite 800, Tyler, TX 75702) will handle all courtroom logistics and local-rule compliance, including pre-hearing coordination with the clerk's office regarding AV setup, binder submissions, and any procedural requirements specific to Judge Gilstrap's courtroom. Jim has appeared before Judge Gilstrap on numerous occasions and is well known to the Court's staff.
C. Prior Markman Rulings of Note
Our review of Judge Gilstrap's prior Markman rulings in analogous technology cases — summarized in detail in Appendix C — reveals several tendencies that are directly relevant to this hearing.
Ordinary Meaning Preservation. In prior silicon-photonics and semiconductor cases, Judge Gilstrap has shown a consistent willingness to adopt constructions that preserve the ordinary meaning of terms where the specification does not clearly limit them. In Photon Dynamics, Inc. v. SiGe Semiconductor Corp., Case No. 2:18-cv-00207-JRG (E.D. Tex. 2019), for example, the Court rejected an attempt to limit the term "optical modulator" to a specific Mach-Zehnder architecture, holding that the claim language and specification supported a broader construction. Similarly, in NanoPath Technologies LLC v. AdvancedSi, Inc., Case No. 2:20-cv-00442-JRG (E.D. Tex. 2021), the Court declined to limit "semiconductor substrate" to a silicon-on-insulator platform where the specification disclosed multiple substrate types.
Means-Plus-Function Analysis. In cases involving means-plus-function disputes, Judge Gilstrap conducts a rigorous two-step analysis: first, determining whether the claim term invokes 35 U.S.C. § 112(f) (i.e., whether the term is a nonce or functional term that does not recite sufficient structure), and second, if § 112(f) is triggered, identifying the corresponding structure disclosed in the specification. Judge Gilstrap has shown that he will invoke § 112(f) where the claim language clearly uses functional terms without structural modifiers, but he will not lightly construe terms as means-plus-function where they connote sufficiently definite structure to a person of ordinary skill in the art.
Internal Analysis Alert. Our Means-Plus-Function Analysis Memorandum, dated October 5, 2024, identified two terms in the asserted patents that could potentially be subject to § 112(f) treatment: "means for routing optical signals between the plurality of channels" in Claim 9 of the '847 Patent, and "processing unit for performing digital signal processing on the signal signal" in Claim 15 of the '193 Patent. Neither party has briefed these terms as means-plus-function in the current Joint Claim Construction Chart, but Alan should be prepared to address the issue if the Court raises it sua sponte. Our contingency strategy is detailed in Section IV below.
III. DISPUTED TERM-BY-TERM ANALYSIS
The following analysis covers each of the twelve remaining disputed claim terms. For each term, we provide: (A) the claim language and patent(s) at issue; (B) OWS's proposed construction; (C) Lumicore's proposed construction; (D) key intrinsic and extrinsic evidence supporting OWS's position; (E) Lumicore's best arguments; (F) anticipated questions from the Court; (G) recommended responses and sound bites; and (H) fallback positions. Terms 1 through 4 receive full treatment as the highest-priority terms. Terms 5 through 12 receive condensed treatment as secondary-priority terms.
Term 1: "waveguide multiplexer"
A. Claim Language and Patent(s)
The term "waveguide multiplexer" appears in Claims 1, 3, 5, 9, and 14 of the '847 Patent (U.S. Patent No. 10,234,847, entitled "Multi-Channel Silicon Photonic Waveguide Multiplexer with Low Insertion Loss," filed September 14, 2016, and issued March 19, 2019). The term is also referenced in Claims 1 and 10 of the '193 Patent (U.S. Patent No. 10,891,193), where the waveguide multiplexer forms part of the claimed transceiver system.
This is the single most important term in the case. Its construction will directly control the scope of OWS's infringement allegations against Lumicore's two highest-revenue accused products: the LumiLink 400G-ZR+ (FY23 revenue of approximately $94.8 million) and the LumiLink 800G-DR8 (FY23 revenue of approximately $128.4 million). If the Court adopts a broad construction consistent with OWS's proposal, both accused products fall squarely within the claims. If the Court adopts Lumicore's narrow construction limiting the term to arrayed waveguide gratings, the LumiLink 800G-DR8 — which uses an Echelle grating-based multiplexer — would fall outside the literal scope of the claims, requiring OWS to rely on the doctrine of equivalents for that product.
B. OWS's Proposed Construction
OWS proposes that "waveguide multiplexer" be construed to mean:
"An optical device that combines multiple optical signals of different wavelengths onto a single waveguide."
This construction is broad and functional, encompassing multiple multiplexer architectures as understood by a person of ordinary skill in the art at the time of the invention, including but not limited to arrayed waveguide gratings (AWGs), Echelle gratings, Mach-Zehnder interferometer-based multiplexers, and ring-resonator-based multiplexers. It is grounded in the claim language itself, which uses the generic term "waveguide multiplexer" without reference to any specific architecture, and it is fully consistent with the way the term is used throughout the specification and understood in the relevant technical literature.
C. Lumicore's Proposed Construction
Lumicore proposes that "waveguide multiplexer" be construed to mean:
"An arrayed waveguide grating that combines optical signals using a slab coupler and phase-shifted waveguide array."
This construction is extraordinarily narrow. It limits the claim scope to a single specific multiplexer architecture — the arrayed waveguide grating — and further requires the presence of specific structural sub-elements (a slab coupler and a phase-shifted waveguide array). If adopted, this construction would exclude all other multiplexer types, including the Echelle grating used in Lumicore's LumiLink 800G-DR8 product. This construction cannot be reconciled with the claim language, the specification, the prosecution history, or the understanding of a person of ordinary skill in the art.
D. Key Evidence Supporting OWS
Specification. The '847 Patent specification describes the invention as a "waveguide multiplexer" generically in the abstract and summary sections. While the specification provides a detailed discussion of an AWG-based multiplexer as a preferred embodiment, it also expressly references "alternative multiplexing architectures" in column 4, lines 32–45. Specifically, the specification states: "While the following description focuses on an arrayed waveguide grating implementation, the principles of the invention are applicable to alternative multiplexing architectures, including but not limited to Echelle gratings and ring-resonator-based multiplexers." This passage is critical because it demonstrates that the patentee expressly contemplated and disclosed multiplexer architectures beyond the AWG. Under Phillips, a construction that would exclude embodiments specifically contemplated and disclosed in the specification is presumptively incorrect.
Claims. The claim structure of the '847 Patent provides powerful support for OWS's construction through the doctrine of claim differentiation. Independent Claim 1 recites a "waveguide multiplexer" without any architectural limitation. Dependent Claim 5 then specifies: "The device of claim 1, wherein the waveguide multiplexer comprises an arrayed waveguide grating." If "waveguide multiplexer" in Claim 1 already meant "arrayed waveguide grating," as Lumicore contends, then Claim 5 would be entirely superfluous — it would add nothing to the scope of Claim 1. This result is inconsistent with the well-established interpretive canon of claim differentiation, which creates a presumption that each claim in a patent, and each limitation within a claim, has a different scope. See Phillips, 415 F.3d at 1314-15. Our Claim Differentiation Analysis, prepared on October 8, 2024, provides a comprehensive mapping of the claim dependencies across the '847 Patent and confirms this argument.
Prosecution History. The prosecution history of the '847 Patent does not contain any narrowing amendment or disclaimer that would justify limiting "waveguide multiplexer" to AWGs. During prosecution, the examiner's November 2017 office action applied a § 102 anticipation rejection based on a prior art reference (Takahashi et al., IEEE Photonics Technology Letters, March 2014) that disclosed a waveguide multiplexer. In that rejection, the examiner used the term "waveguide multiplexer" in its broadest sense, without limiting it to any particular architecture. The applicant overcame the rejection by distinguishing Takahashi on other grounds — specifically, the "low insertion loss" and "channel-count" limitations — without making any narrowing argument or amendment with respect to the "waveguide multiplexer" term itself. At no point during prosecution did the applicant disclaim any particular multiplexer architecture, and at no point did the applicant characterize the term as limited to AWGs.
Dr. Ashford Declaration (November 15, 2024). Dr. Caroline Ashford, Professor of Electrical Engineering and Photonics at the Northfield Institute of Technology, opines in her declaration that a person of ordinary skill in the art — defined as an individual with an M.S. or Ph.D. in electrical engineering or photonics, with three or more years of experience in silicon-photonic integrated circuit design — would understand the term "waveguide multiplexer" to encompass all optical devices that combine multiple wavelength channels onto a single output waveguide, without limitation to any particular architecture. Dr. Ashford's opinion is based on her review of the intrinsic evidence, her extensive experience in silicon photonics (over 25 years, 150+ peer-reviewed publications, and prior service as a technical expert in 12 patent matters), and her survey of the relevant technical literature.
Dr. Huang Declaration (November 15, 2024). Dr. Jian-Wei Huang, the named inventor of the '847 Patent and former CTO of Optiwave Semiconductor Corp., testified in his declaration that the term "waveguide multiplexer" was intentionally drafted in broad, generic terms to cover the full range of on-chip wavelength-multiplexing solutions. Dr. Huang explained that at the time of drafting, he and his co-inventors recognized that the silicon photonics industry was developing multiple multiplexer architectures and intended the patent claims to encompass all of them.
Extrinsic Evidence. The Appendix of Extrinsic Evidence filed with OWS's Opening Brief on November 15, 2024, includes the IEEE Standard Dictionary of Electrical and Electronics Terms definition of "waveguide multiplexer" (which defines the term broadly as a device for combining multiple signals of different wavelengths) and two leading photonics textbooks — S.L. Chuang, Physics of Photonic Devices (2d ed. 2009), and T. Tamir (ed.), Guided-Wave Optoelectronics (2d ed. 1990) — both of which define "waveguide multiplexer" without limiting it to any particular architecture. This extrinsic evidence is consistent with and confirmatory of OWS's proposed construction.
E. Lumicore's Best Arguments
Lumicore's principal argument is that the '847 Patent specification devotes the overwhelming majority of its detailed description to an AWG-based multiplexer, and that the absence of detailed embodiments for alternative multiplexer types indicates that the patentee intended a narrow scope limited to the AWG architecture. Lumicore will emphasize that the specification's drawings — particularly Figure 3, which depicts the internal structure of an arrayed waveguide grating with a slab coupler and phase-shifted waveguide array — illustrate only the AWG architecture and do not depict any alternative multiplexer structure.
Lumicore will also argue that the brief reference to "alternative multiplexing architectures" in column 4, lines 32–45, is merely a passing acknowledgment that does not constitute a meaningful disclosure, and that limiting the claims to AWGs is consistent with the "full scope of the invention as disclosed." Lumicore will contend that the reference to alternative architectures is insufficient to support a construction that encompasses them because the patentee did not provide an enabling disclosure of those alternative architectures.
In support of its position, Lumicore will cite the declaration of Dr. Rajiv Sundaram, Professor of Photonic Engineering at Pacific Western University, who opines that a person of ordinary skill in the art would understand the term "waveguide multiplexer" in the context of this specification to refer specifically to an AWG-based device. Dr. Sundaram's declaration was submitted with Lumicore's Responsive Brief on December 6, 2024, and was supplemented with additional analysis in the Sur-Reply filed January 10, 2025.
We note that Dr. Sundaram's declaration is vulnerable on several grounds: (1) it relies heavily on the specification's focus on the AWG embodiment while minimizing the explicit reference to alternative architectures; (2) it conflates the scope of the disclosure with the scope of the claims; and (3) Dr. Sundaram's definition of a POSITA is narrower than Dr. Ashford's and may not accurately reflect the skill level in the relevant art at the time of the invention.
F. Anticipated Questions from Judge Gilstrap
Based on our review of Judge Gilstrap's prior Markman rulings and his typical questioning patterns, we anticipate the following questions on this term:
Question 1: "Counsel, if the specification only discloses an arrayed waveguide grating as the multiplexer, why shouldn't I limit the claim term to that embodiment?"
This is the most likely question and the one that must be answered decisively. It reflects Judge Gilstrap's standard approach of probing whether the specification mandates a narrower construction than the claim language suggests. Alan should be prepared for this question to come early in the presentation.
Question 2: "Does the claim differentiation argument hold up if Claim 5 is simply specifying a preferred embodiment rather than defining the boundary of Claim 1?"
This question probes whether the claim differentiation argument is as strong as OWS contends. The Court may suggest that Claim 5 is merely a "preferred species" claim that does not necessarily establish the outer boundary of the genus in Claim 1. Alan should have a clear response that explains why the claim differentiation canon applies here.
Question 3: "Did the applicant ever amend the claims during prosecution in a way that would narrow the scope of this term?"
This question reflects the Court's diligent review of prosecution history for evidence of disclaimer or narrowing. The answer is straightforward: there was no narrowing amendment to this term.
Question 4: "What would the practical impact be on infringement if I adopt Lumicore's construction?"
This question reflects Judge Gilstrap's characteristic interest in the real-world consequences of claim constructions. Alan should answer this question directly and transparently, without appearing to advocate for a construction based on its litigation consequences.
G. Recommended Responses and Sound Bites
Response to Question 1: "Your Honor, it is blackletter law that claims are not to be limited to preferred embodiments. The Federal Circuit's en banc decision in Phillips teaches that the specification illuminates the meaning of claim terms but does not serve as a limitation on those terms unless there is a clear and unmistakable disclaimer. Here, the specification does not merely fail to disclaim alternative architectures — it expressly references them. Column 4, lines 32–45, states that 'the principles of the invention are applicable to alternative multiplexing architectures, including but not limited to Echelle gratings and ring-resonator-based multiplexers.' The claims intentionally use the generic term 'waveguide multiplexer,' and the specification expressly acknowledges that the invention is not limited to AWGs. Limiting 'waveguide multiplexer' to arrayed waveguide gratings would effectively read out the specification's own acknowledgment that other architectures fall within the scope of the invention."
Response to Question 2: "Your Honor, claim differentiation is a strong interpretive canon recognized by the Federal Circuit. If Claim 1 already meant 'arrayed waveguide grating,' as Lumicore contends, then Claim 5 — which adds the express limitation 'wherein the waveguide multiplexer comprises an arrayed waveguide grating' — would be entirely redundant. It would contribute nothing to the patent. The drafter clearly intended Claim 1 to cover the broader genus of waveguide multiplexers and Claim 5 to specify one particular species within that genus. This is not merely a question of preferred versus non-preferred embodiments; it is a question of claim scope. If Claim 5 has independent meaning — and it must — then Claim 1 must be broader than Claim 5."
Response to Question 3: "No, Your Honor. There was no narrowing amendment to the term 'waveguide multiplexer' at any point during prosecution of the '847 Patent. The examiner allowed the term as originally filed. The applicant did not disclaim any multiplexer architecture, did not amend the claims to add structural limitations to the multiplexer, and did not make any arguments to the examiner that the term was limited to AWGs. The prosecution history is entirely consistent with the broad construction we propose."
Response to Question 4: Alan should address this question forthrightly while avoiding any appearance of results-oriented advocacy. "Your Honor, we believe the correct construction is dictated by the intrinsic evidence, and we would urge this construction regardless of its infringement implications. But to answer the Court's question directly: adopting Lumicore's construction would effectively allow Lumicore to use alternative on-chip multiplexer structures — such as Echelle gratings — to avoid infringement of claims that were intended to cover them. The patentee specifically disclosed these alternative architectures and used a generic claim term to encompass them. Permitting a defendant to evade infringement by substituting one multiplexer architecture for another, where both are expressly contemplated by the specification, would be precisely the kind of result that the Phillips framework is designed to prevent."
H. Fallback Position
If the Court appears inclined to impose some structural limitation on the term — for example, if Judge Gilstrap signals concern that OWS's proposed construction is too broad and encompasses devices that are not truly "waveguide" multiplexers — we have prepared the following fallback construction:
Fallback: "An optical device implemented on a photonic integrated circuit that combines multiple optical signals of different wavelengths onto a single output waveguide."
This fallback adds the photonic integrated circuit (PIC) context, which is consistent with the specification's disclosure and narrows the term to on-chip devices, without limiting the term to any particular multiplexer architecture. It addresses any concern that the term might be read so broadly as to encompass free-space or fiber-optic multiplexers that are not implemented on a waveguide platform.
Absolute Floor: If the Court adopts Lumicore's AWG-only construction notwithstanding OWS's arguments, we preserve doctrine of equivalents arguments for the '847 Patent claims. However, this outcome would significantly complicate the infringement case against the LumiLink 800G-DR8, which uses an Echelle grating rather than an AWG, and would require substantial additional expert analysis from Dr. Ashford to establish infringement under the function-way-result test. This is the least favorable scenario, and Alan should make every effort to avoid it.
Term 2: "integrated on a silicon substrate"
A. Claim Language and Patent(s)
The term "integrated on a silicon substrate" appears in Claims 1, 3, 7, 10, 15, and 18 of the '193 Patent (U.S. Patent No. 10,891,193, entitled "High-Bandwidth Coherent Optical Transceiver Integrated on Silicon Substrate," filed April 7, 2017, and issued January 12, 2021). This term is critical because it appears in every independent claim of the '193 Patent and affects the infringement analysis for all three accused products: the LumiLink 400G-ZR+ (FY23 revenue: approximately $94.8 million), the LumiLink 800G-DR8 (FY23 revenue: approximately $128.4 million), and the LumiEdge 1600G-LR (FY23 revenue: approximately $41.7 million).
The dispute over this term centers on a fundamental question in silicon photonics: whether "integrated on a silicon substrate" requires monolithic fabrication on a single silicon die or whether it also encompasses hybrid bonding and heterogeneous integration techniques. This is not merely an academic distinction; it goes to the heart of how the silicon photonics industry designs and manufactures optical transceivers. Heterogeneous integration — in which III-V semiconductor gain materials (such as indium phosphide) are bonded to a silicon photonics substrate — is a well-established and increasingly dominant fabrication approach. Lumicore's accused products use heterogeneous integration, and its proposed construction is transparently designed to exclude them from the claim scope.
B. OWS's Proposed Construction
OWS proposes that "integrated on a silicon substrate" be construed to mean:
"Formed on or within a silicon-based wafer using semiconductor fabrication processes."
This construction encompasses all three standard silicon-photonics fabrication approaches: monolithic integration (all elements fabricated on a single silicon die), hybrid bonding (discrete components assembled and bonded to a silicon substrate), and heterogeneous integration (III-V materials grown on or bonded to a silicon substrate using wafer-level processes). The construction captures the essential meaning of the term — that the silicon substrate is the integration platform — without imposing a manufacturing-process limitation that the claims do not contain.
C. Lumicore's Proposed Construction
Lumicore proposes that "integrated on a silicon substrate" be construed to mean:
"Monolithically fabricated on a single silicon die without hybrid bonding or heterogeneous integration."
This construction would exclude any device that uses multi-chip integration, flip-chip bonding of III-V materials on silicon, or any other heterogeneous integration technique. As noted above, this is precisely how Lumicore has designed its accused products, and the proposed construction is transparently driven by litigation strategy. It is not supported by the claims, the specification, or the prosecution history.
D. Key Evidence Supporting OWS
Specification. The '193 Patent specification discusses "integration on a silicon substrate" as referring to the platform — that is, silicon as the base material and integration substrate — rather than as requiring a specific monolithic fabrication methodology. Column 6, lines 15–28, describes "hybrid integration approaches" as within the scope of the invention, stating: "In certain embodiments, III-V gain materials may be integrated on the silicon substrate through heterogeneous bonding or other integration techniques known in the art." This passage is direct and unambiguous: the specification expressly contemplates heterogeneous integration as falling within the meaning of "integrated on a silicon substrate."
Prosecution History. During prosecution of the '193 Patent, the applicant's patent counsel at Cascade IP Advisors, LLC (Dr. Martin Chu) did not disclaim hybrid or heterogeneous integration at any point. The prosecution history contains a § 102 anticipation rejection based on the Takahashi et al. reference, which was overcome by amending the "coherent detection module" limitation — not by narrowing the scope of "integrated on a silicon substrate." The amendments and arguments made to overcome Takahashi focused entirely on the distinction between coherent detection and direct detection; they had nothing to do with the integration approach.
Provisional Application No. 62/499,117 (filed April 7, 2017). The provisional application, which establishes the priority date for both the '193 Patent and the '015 Patent, explicitly references "heterogeneous integration of III-V gain materials on a silicon photonics platform" as an embodiment of the invention. This is powerful intrinsic evidence that the applicant intended "integrated on a silicon substrate" to encompass heterogeneous integration from the earliest filing date.
Dr. Ashford Declaration. Dr. Ashford opines that a person of ordinary skill in the art, as of the April 7, 2017 filing date, would understand "integrated on a silicon substrate" to encompass any fabrication approach in which silicon is the primary substrate material, including monolithic, hybrid, and heterogeneous integration. Dr. Ashford's opinion is supported by her review of the specification, the prosecution history, and the state of the art in 2017.
Industry Context. By the filing date of the '193 Patent in April 2017, heterogeneous integration was a well-established and commercially significant technique in silicon photonics. intel had commercially deployed heterogeneous integration for its silicon photonics transceivers, and academic groups at UC Santa Barbara, Ghent University, and elsewhere had published extensively on the technology. A person of ordinary skill in the art in 2017 would not have understood "integrated on a silicon substrate" to exclude heterogeneous integration — doing so would have been contrary to the prevailing understanding in the field.
E. Lumicore's Best Arguments
Lumicore's principal argument centers on the word "integrated" in the claim term. Lumicore contends that "integrated on" connotes a unitary fabrication process on a single substrate — i.e., monolithic integration — and that the term should be distinguished from "assembled on," "bonded to," or "attached to" a silicon substrate. Lumicore argues that if the patentee had intended to cover heterogeneous integration, it would have used different claim language, such as "formed on or bonded to a silicon substrate."
Lumicore will also point to certain prosecution-history statements in which the applicant emphasized the "integration" of all functional blocks on the silicon substrate as a key inventive feature. Lumicore will characterize these statements as a commitment to monolithic fabrication, arguing that the applicant distinguished prior art by highlighting the single-substrate integration approach.
In support of its position, Dr. Sundaram's declaration argues that a person of ordinary skill in the art would draw a clear distinction between "integrated on" (which, in Dr. Sundaram's view, connotes monolithic fabrication) and "assembled on" or "bonded to" (which connote heterogeneous integration). Dr. Sundaram contends that the two approaches involve fundamentally different fabrication processes and that the term "integrated on" would be understood by a POSITA to refer only to monolithic fabrication.
We note that Dr. Sundaram's position is weakened by the specification's own use of the term "integrated" in conjunction with heterogeneous bonding (column 6, lines 15–28), and by the provisional application's explicit reference to heterogeneous integration as an embodiment.
F. Anticipated Questions from Judge Gilstrap
Question 1: "If 'integrated on' means both monolithic and heterogeneous integration, is there any structural limitation left in this term, or does it just mean 'associated with silicon in some way'?"
This question reflects the Court's concern about overbreadth. Alan should demonstrate that OWS's construction imposes meaningful structural limits while still encompassing the full scope of the term.
Question 2: "Did the applicant ever distinguish prior art during prosecution based on monolithic integration?"
This question probes the prosecution history for evidence of disavowal. Alan should be prepared to walk through the specific amendments and arguments made during prosecution.
Question 3: "What does the provisional application say about the scope of integration techniques?"
This question signals the Court's interest in the earliest-filed disclosure as evidence of the inventor's intent. Alan should have the relevant passage of the provisional application readily accessible.
G. Recommended Responses
Response to Question 1: "Your Honor, 'integrated on a silicon substrate' does impose meaningful structural limits. It requires that silicon serve as the substrate — the foundation on which the photonic and electronic elements are fabricated or assembled. And it requires that semiconductor fabrication processes be used. This construction excludes, for example, discrete optical components assembled on non-silicon platforms, fiber-optic systems, or free-space optical assemblies. But it does not require that every element be monolithically fabricated on a single die — that would be a manufacturing-process limitation that the claims do not recite and the specification did not impose. The claims say 'integrated on a silicon substrate,' not 'monolithically fabricated on a single silicon die.'"
Response to Question 2: "Your Honor, the prosecution history shows that the applicant overcame the Takahashi prior art rejection by amending the 'coherent detection module' limitation — not by narrowing 'integrated on a silicon substrate.' The amendment added 'using coherent detection techniques' to distinguish Takahashi's direct-detection approach from the claimed coherent-detection approach. There was no amendment, argument, or statement in the prosecution history that disclaimed hybrid or heterogeneous integration. The integration approach was simply not the basis for distinguishing the prior art."
Response to Question 3: "Your Honor, the provisional application — filed April 7, 2017, the very same date as the '193 Patent application — expressly discusses 'heterogeneous integration of III-V gain materials on a silicon photonics platform' as an embodiment of the invention. This is powerful intrinsic evidence that the inventors understood 'integrated on a silicon substrate' to encompass heterogeneous integration from the outset. It would be anomalous to adopt a construction that excludes an approach the inventors expressly contemplated and disclosed on the filing date."
H. Fallback Position
If the Court is inclined to add specificity to OWS's construction, we have prepared the following fallback:
Fallback: "Formed on or within a silicon-based wafer, using semiconductor fabrication processes including monolithic, hybrid, or heterogeneous integration techniques."
This construction is more specific than our primary proposal but expressly preserves all three fabrication approaches. It responds to any concern that OWS's primary construction is too open-ended by providing an illustrative (but non-exhaustive) list of encompassed techniques.
Absolute Floor: "Fabricated on a silicon substrate using photonic semiconductor fabrication processes, including heterogeneous integration." This is the narrowest construction that still preserves coverage of Lumicore's accused products, all of which use heterogeneous integration on a silicon substrate. If the Court adopts a construction narrower than this — i.e., one that excludes heterogeneous integration — OWS's infringement case on the '193 Patent would be severely compromised across all three accused products.
Term 3: "micro-channel heat sink"
A. Claim Language and Patent(s)
The term "micro-channel heat sink" appears in Claims 1, 4, 6, and 11 of the '562 Patent (U.S. Patent No. 9,678,562, entitled "Method for Thermal Management of Photonic Integrated Circuits Using Embedded Micro-Channel Heat Sinks," filed November 22, 2014, and issued June 13, 2017). The '562 Patent was originally assigned to Solara Optics, Inc. and was acquired by OWS pursuant to an Asset Purchase Agreement dated June 15, 2018, for $34.5 million.
This term is relevant to two of the three accused products: the LumiLink 400G-ZR+ and the LumiLink 800G-DR8. Both products were subjected to teardown analysis by Benchmark Semiconductor Analysis, LLC (Kevin Ng, Lead Engineer). The teardown report for the LumiLink 400G-ZR+ (dated December 12, 2022) and the teardown report for the LumiLink 800G-DR8 (dated June 2023) both confirmed the presence of micro-channel structures in these products.
B. OWS's Proposed Construction
OWS proposes that "micro-channel heat sink" be construed to mean:
"A heat-dissipating structure containing channels with a hydraulic diameter of less than 1 mm."
This construction is consistent with the broad definition of micro-channels in the thermal-management literature and with the specification's own description. The less-than-1-mm threshold for hydraulic diameter is the widely recognized boundary between micro-channels and conventional channels in the engineering literature.
C. Lumicore's Proposed Construction
Lumicore proposes that "micro-channel heat sink" be construed to mean:
"A closed-loop liquid-cooling system with channels having a hydraulic diameter between 10 µm and 200 µm."
Lumicore's construction imposes two additional limitations not found in the claim language. First, it requires a "closed-loop liquid-cooling system," which would exclude passive or air-cooled micro-channel heat sinks and open-loop designs. Second, it narrows the dimensional range of the channels to 10–200 µm, which would exclude channels in the 200 µm to 1 mm range. Both limitations are unsupported by the claims and specification.
Critically, the Kevin Ng teardown identified micro-channel structures in the LumiLink 400G-ZR+ with measured hydraulic diameters of approximately 150–350 µm. Under OWS's proposed construction, these structures are clearly within scope. Under Lumicore's proposed construction, structures with hydraulic diameters above 200 µm would fall outside the claim scope — meaning that a significant portion of the identified structures in Lumicore's own product would be excluded from literal infringement.
D. Key Evidence Supporting OWS
Specification. The '562 Patent specification defines "micro-channel" as "channels with dimensions on the micro-scale" (column 3, lines 8–12). This definition does not impose a rigid upper or lower bound. The specification goes on to disclose embodiments with hydraulic diameters ranging from 50 µm to 800 µm, demonstrating that the patentee contemplated channels across a wide dimensional range. Notably, the specification discloses embodiments at 800 µm — well beyond Lumicore's proposed 200 µm upper limit. A construction that excludes the patentee's own disclosed embodiments is presumptively incorrect under Phillips.
Furthermore, the specification describes both active (liquid-cooled) and passive (air-cooled, phase-change) micro-channel heat sinks. Column 5, lines 40–52, describes "air-cooled micro-channel heat sinks for low-power photonic integrated circuits," directly contradicting Lumicore's attempt to limit the term to "closed-loop liquid-cooling" systems.
Prosecution History. The prosecution history of the '562 Patent does not contain any amendments or arguments that would narrow the term "micro-channel heat sink" to a specific dimensional range or cooling methodology. The applicant's patent counsel at Cascade IP Advisors prosecuted the patent without making any narrowing concessions regarding this term. The examiner applied the broader definition of micro-channels during prosecution, and the claims were allowed without amendment to this term.
Prior Art Context. During prosecution, the examiner considered the prior art reference Dr. Li Wei, "Thermal Solutions for PICs," presented at the Optical Fiber Conference (OFC) 2013. This reference discusses micro-channels in the broad sense — i.e., channels with hydraulic diameters of less than 1 mm — consistent with the well-established definition in the thermal-management literature. The examiner's treatment of this reference confirms that the term "micro-channel" was understood during prosecution in its broad sense.
Kevin Ng Deposition (January 7, 2025). Kevin Ng of Benchmark Semiconductor Analysis testified at his deposition that the teardown of the LumiLink 400G-ZR+ identified micro-channel structures with measured hydraulic diameters of approximately 150–350 µm. This testimony is significant because it establishes that Lumicore's own products contain channels that fall within OWS's proposed construction but partially outside Lumicore's proposed 10–200 µm range. Mr. Ng further testified that the channels he observed were consistent with what he, as an experienced semiconductor analyst, would identify as "micro-channels" based on industry convention.
E. Lumicore's Best Arguments
Lumicore will argue that the specification's detailed description focuses on active cooling — specifically, closed-loop liquid-cooling systems in which a coolant is pumped through the micro-channels. Lumicore will contend that the specification's emphasis on liquid cooling indicates that the term "micro-channel heat sink" was intended to refer to active liquid-cooled systems, not passive or air-cooled designs.
Lumicore will further argue that the specific dimensional range of 10–200 µm is supported by the specification's discussion of "optimal thermal performance" in that range. The specification does contain a passage discussing the relationship between channel dimensions and thermal efficiency, which Lumicore will characterize as establishing the boundaries of the claimed "micro-channel" dimensions.
Dr. Sundaram's declaration supports Lumicore's position by arguing that channels with hydraulic diameters above 200 µm are properly classified as "mini-channels," not "micro-channels," in the thermal-engineering literature. Dr. Sundaram cites several references in the thermal-management literature that draw a distinction between micro-channels and mini-channels at approximately 200 µm.
We note that Dr. Sundaram's position is contradicted by the specification's own disclosure of embodiments at 800 µm, and that the thermal-management literature is not uniform on the precise boundary between "micro" and "mini" channels — the less-than-1-mm definition is at least equally well-established.
F. Anticipated Questions from Judge Gilstrap
Question 1: "The specification discusses optimal performance in a specific dimensional range. Why shouldn't the claim be limited to that range?"
Question 2: "Is there a difference in the art between a micro-channel and a mini-channel, and if so, where does the line fall?"
Question 3: "Does the specification ever disclose a passive micro-channel heat sink, or only active liquid-cooled systems?"
G. Recommended Responses
Response to Question 1: "Your Honor, the specification discusses optimal thermal performance in a particular dimensional range, but it also expressly discloses embodiments with hydraulic diameters up to 800 µm — well outside Lumicore's proposed 200 µm upper limit. If the Court were to limit the claims to the 'optimal' range, it would exclude the patentee's own disclosed embodiments. Under Phillips and its progeny, a construction that reads out disclosed embodiments is presumptively incorrect. The specification's discussion of optimal performance identifies a preferred range; it does not redefine the term 'micro-channel' to exclude larger channels that are still disclosed and claimed."
Response to Question 2: "Your Honor, the specification itself uses the term 'micro-channel' to encompass channels with dimensions on the 'micro-scale,' and it discloses embodiments ranging from 50 µm to 800 µm. The thermal-management literature is not uniform on the precise dividing line between 'micro' and 'mini' channels — some references draw the line at 200 µm, others at 500 µm, and others at 1 mm. But the intrinsic evidence controls, and the specification's own embodiment at 800 µm demonstrates that the patentee did not draw the line at 200 µm. The distinction Lumicore tries to draw at 200 µm is not supported by the intrinsic record and is contradicted by the specification's own disclosure."
Response to Question 3: "Yes, Your Honor. The specification expressly discloses passive micro-channel heat-sink configurations. Column 5, lines 40–52, describes 'air-cooled micro-channel heat sinks for low-power photonic integrated circuits.' The patentee recognized that not all applications require active liquid cooling and disclosed passive alternatives. There is no basis in the claims or the specification for importing a 'closed-loop liquid-cooling' requirement into the term 'micro-channel heat sink.'"
H. Fallback Position
Fallback: "A heat-dissipating structure containing channels with a hydraulic diameter of less than 1 mm, which may be actively or passively cooled."
This fallback makes the cooling-mode breadth explicit, which may be helpful if the Court is uncertain about whether passive cooling is within the scope of the term. It does not change the substance of our primary construction but provides additional clarity.
Absolute Floor: "A heat-dissipating structure containing channels with a hydraulic diameter between 10 µm and 1 mm." This construction accepts a lower bound of 10 µm (which is unlikely to be relevant to any accused product or prior art) but preserves the critical upper boundary of 1 mm, ensuring coverage of Lumicore's 150–350 µm structures identified in the Benchmark teardown.
Term 4: "polarization-diverse grating coupler"
A. Claim Language and Patent(s)
The term "polarization-diverse grating coupler" appears in Claims 1, 5, 8, 12, and 16 of the '015 Patent (U.S. Patent No. 11,402,015, entitled "Polarization-Diverse Grating Coupler for Silicon Photonic Transceivers," filed August 30, 2019, and issued August 2, 2022). This term is relevant to two accused products: the LumiLink 800G-DR8 (FY23 revenue: approximately $128.4 million) and the LumiEdge 1600G-LR (FY23 revenue: approximately $41.7 million).
This term has a critical interaction with OWS's doctrine of equivalents contentions for Claim 12 of the '015 Patent. During prosecution, the applicant made a narrowing amendment to Claim 12 to overcome a § 103 obviousness rejection based on a combination of the Bergmann patent (U.S. Patent No. 8,412,007) and the Simonsen PCT application (PCT/EP2015/071234). That amendment related to the "two-dimensional sub-wavelength grating" limitation in dependent Claim 12 — not to the "polarization-diverse grating coupler" term in independent Claim 1. The distinction between these terms, and the scope of prosecution history estoppel, is central to the analysis of this term.
B. OWS's Proposed Construction
OWS proposes that "polarization-diverse grating coupler" be construed to mean:
"A grating coupler capable of coupling light of two orthogonal polarization states."
This construction is functional, encompassing all architectures that achieve polarization-diverse coupling, including but not limited to one-dimensional gratings with external polarization splitters and two-dimensional gratings that inherently handle both polarization states. It is grounded in the claim language, which does not specify any particular grating architecture, and is consistent with the specification's disclosure of multiple embodiments.
C. Lumicore's Proposed Construction
Lumicore proposes that "polarization-diverse grating coupler" be construed to mean:
"A two-dimensional grating coupler with a polarization-splitting element that simultaneously couples TE and TM modes."
This construction imposes two limitations not found in the claim language. First, it limits the grating architecture to two-dimensional gratings, excluding one-dimensional grating designs. Second, it requires "simultaneous" coupling of TE and TM modes, which would exclude sequential coupling approaches in which the two polarization states are coupled in separate steps. Both limitations are unsupported by the claims and are contradicted by the specification.
D. Key Evidence Supporting OWS
Specification. The '015 Patent specification describes the two-dimensional grating coupler as a "preferred embodiment" (column 4, line 15) but does not limit the invention to that architecture. The specification states: "the principles of the invention apply to any grating coupler configuration achieving polarization-diverse light coupling" (column 3, lines 50–55). This is an express statement of breadth by the patentee. Moreover, the specification discloses an alternative embodiment using a one-dimensional grating with an external polarization-splitting rotator (column 5, lines 12–25), confirming that the invention is not limited to 2D gratings.
Claims. As with Term 1, the claim structure of the '015 Patent provides strong support for OWS's construction through claim differentiation. Independent Claim 1 uses the broad term "polarization-diverse grating coupler." Dependent Claim 8 then specifies: "wherein the polarization-diverse grating coupler comprises a two-dimensional grating structure." If Claim 1 already meant a 2D grating coupler, Claim 8 would be entirely superfluous — adding nothing to the scope of Claim 1. The same claim-differentiation logic that applies to Term 1 applies with equal force here.
Prosecution History. The narrowing amendment made during prosecution of the '015 Patent was directed to Claim 12, not to Claim 1 or the "polarization-diverse grating coupler" term. Specifically, the applicant amended Claim 12 to add the limitation "two-dimensional sub-wavelength grating" to overcome a § 103 rejection combining the Bergmann patent with the Simonsen PCT application. This amendment was specific to dependent Claim 12 and its particular limitation. It did not amend independent Claim 1, did not narrow the term "polarization-diverse grating coupler," and did not represent a patent-wide commitment to 2D grating architecture.
Our Prosecution History Estoppel Analysis for the '015 Patent (dated October 12, 2024) concludes that the narrowing amendment to Claim 12 does not create prosecution history estoppel for Claim 1 or for other claims that do not contain the amended limitation. For Claim 12 specifically, the Festo presumption may apply, but OWS can rebut the presumption through the tangential-relation exception because the amendment was directed to the sub-wavelength grating structure, not to the broader concept of polarization-diverse coupling.
Dr. Ashford Declaration. Dr. Ashford opines that a person of ordinary skill in the art would understand "polariza