UNITED STATES DISTRICT COURT EASTERN DISTRICT OF TEXAS MARSHALL DIVISION
OPTIWAVE SEMICONDUCTOR CORP.,
Plaintiff,
v.
LUMICORE TECHNOLOGIES, INC.,
Defendant.
Civil Action No. 2:24-cv-00319-JRG
Judge James R. Gilstrap
JOINT CLAIM CONSTRUCTION CHART (FINAL)
Filed: January 15, 2025
I. INTRODUCTION AND PROCEDURAL POSTURE
Pursuant to the Court's Scheduling Order (Docket Entry No. 27, issued August 12, 2024), the Docket Control Order entered in this case, and the Patent Rules for the Eastern District of Texas, Plaintiff Optiwave Semiconductor Corp. ("OWS") and Defendant Lumicore Technologies, Inc. ("Lumicore") (collectively, the "Parties") hereby jointly submit this Final Joint Claim Construction Chart (the "Chart") for the Court's consideration in advance of the Markman hearing.
This Chart identifies all fourteen (14) claim terms in dispute that were originally set forth in the Parties' Joint Claim Construction Statement (D.E. 40, filed October 28, 2024). Since the filing of the Joint Claim Construction Statement, the Parties have continued to confer in good faith regarding the proper construction of each disputed term. As a result of those conferences, the Parties have reached agreement on the construction of two (2) terms, which are set forth in Section III below. The Parties remain in dispute regarding the proper construction of twelve (12) claim terms, which are set forth in detail in Section IV below and are submitted to the Court for resolution at the Markman hearing currently scheduled for March 14, 2025.
The claim construction positions set forth in this Chart have been fully briefed by the Parties in the following submissions:
• OWS's Opening Claim Construction Brief (D.E. 44, filed November 15, 2024);
• Lumicore's Responsive Claim Construction Brief (D.E. 48, filed December 6, 2024);
• OWS's Reply Claim Construction Brief (D.E. 52, filed December 20, 2024); and
• Lumicore's Sur-Reply Claim Construction Brief (D.E. 56, filed January 10, 2025, filed by leave of Court pursuant to the Order granting Lumicore's Unopposed Motion for Leave to File Sur-Reply, D.E. 54, entered January 8, 2025).
The Joint Claim Construction Statement (D.E. 40) filed on October 28, 2024 serves as the originating document in which the Parties initially identified the fourteen (14) claim terms in dispute, together with each Party's preliminary proposed constructions, supporting intrinsic evidence, and extrinsic evidence.
Counsel. Plaintiff OWS is represented by Calderwood & Harkness LLP, through lead attorneys Alan Ngo, Marcus Delgado, Wendy Schultz, and Omar Siddiqui, with local counsel Whitmore & Callahan LLP, through James "Jim" Callahan. Defendant Lumicore is represented by Hawthorne Vega & Cruz LLP, through lead attorneys Catherine "Kate" Rourke, Darren Cho, Samantha Briggs, and Rohan Iyer, with local counsel Trask Eddington LLP, through Maria Garza.
II. ASSERTED PATENTS
For reference, OWS asserts four United States patents in this action. The following table provides a brief identification of each asserted patent:
Patent Family Relationships. The '562 Patent and the '847 Patent are in the same patent family. Specifically, the '847 Patent is a continuation of the application that matured into the '562 Patent, and both patents share a common specification disclosure. As such, the construction of overlapping or related claim terms should be consistent across both patents. See Omega Eng'g, Inc. v. Raytek Corp., 334 F.3d 1314, 1334 (Fed. Cir. 2003) (explaining that "claims of patents in the same family . . . should be construed consistently").
The '193 Patent and the '015 Patent share a common provisional application, Provisional Application No. 62/499,117, filed April 7, 2017. Although the non-provisional applications resulting in the '193 Patent and the '015 Patent are not continuations of one another, the shared provisional application and overlapping disclosures warrant consistent construction of any claim terms appearing in both patents.
All four asserted patents are utility patents. All required maintenance fees have been paid and are current as of the date of this filing.
III. AGREED-UPON CONSTRUCTIONS (2 TERMS)
The Parties have reached agreement on the proper construction of the following two (2) claim terms. These agreed constructions are presented to the Court for informational purposes and do not require adjudication at the Markman hearing.
Term A-1. Claim Term: "optical signal"
Patent(s): '847 Patent (U.S. Patent No. 10,234,847); '193 Patent (U.S. Patent No. 10,891,193); '015 Patent (U.S. Patent No. 11,402,015)
Claim(s): '847 Patent, Claims 1, 3, 5, 9, 14; '193 Patent, Claims 1, 3, 7, 10, 15, 18; '015 Patent, Claims 1, 5, 8, 12, 16
Agreed Construction: Plain and ordinary meaning. No construction beyond the plain and ordinary meaning is necessary.
Basis for Agreement: The Parties agree that the term "optical signal" requires no construction beyond its plain and ordinary meaning as understood by a person of ordinary skill in the art ("POSITA") at the time of the relevant inventions. The term "optical signal" is a well-understood and commonly used term in the art of photonics and optical communications, and its meaning is not reasonably in dispute. A POSITA would understand "optical signal" to refer to information conveyed by modulated or unmodulated light. The Parties further agree that this term does not impose any limitation on the wavelength, modulation format, data rate, or polarization state of the light. Both Parties' experts — Dr. Caroline Ashford (for OWS) and Dr. Rajesh Sundaram (for Lumicore) — have confirmed that the term carries its well-understood plain and ordinary meaning in their respective declarations.
Term A-2. Claim Term: "silicon substrate"
Patent(s): '193 Patent (U.S. Patent No. 10,891,193); '562 Patent (U.S. Patent No. 9,678,562); '847 Patent (U.S. Patent No. 10,234,847)
Claim(s): '193 Patent, Claims 1, 3, 7, 10, 15, 18; '562 Patent, Claims 1, 4, 6, 11; '847 Patent, Claims 1, 5
Agreed Construction: Plain and ordinary meaning. A POSITA would understand "silicon substrate" to mean a substrate composed primarily of silicon, including but not limited to bulk silicon wafers, silicon-on-insulator (SOI) wafers, and other silicon-based substrates commonly used in semiconductor fabrication.
Basis for Agreement: Following the exchange of claim construction briefs and further conferral between counsel, the Parties agree that "silicon substrate" should be given its plain and ordinary meaning as understood by a POSITA. The Parties agree that the term encompasses both bulk silicon wafers and silicon-on-insulator (SOI) wafers, which are the two most common substrate types used in silicon photonic fabrication. The Parties further agree that this construction does not require the substrate to be composed exclusively of silicon — for example, an SOI wafer that includes a buried oxide layer remains a "silicon substrate" within the meaning of the claims. This agreed construction is consistent with the use of the term throughout the specifications of all four asserted patents and with the prosecution histories of those patents.
IV. DISPUTED CLAIM CONSTRUCTION CHART (12 REMAINING TERMS)
The following twelve (12) claim terms remain in dispute and are presented to the Court for resolution at the Markman hearing scheduled for March 14, 2025. For each disputed term, the Parties identify: (a) the claim term at issue; (b) the patent(s) and claim(s) in which the term appears; (c) each Party's proposed construction; (d) a description of the nature of the dispute; (e) key intrinsic and extrinsic evidence cited by each Party; and (f) references to the relevant sections of the Parties' claim construction briefs.
Disputed Term 1: "waveguide multiplexer"
Patent(s): '847 Patent (U.S. Patent No. 10,234,847)
Claim(s): Claims 1, 3, 5, 9, 14
OWS's Proposed Construction: "an optical device that combines multiple optical signals of different wavelengths onto a single waveguide"
Lumicore's Proposed Construction: "an arrayed waveguide grating that combines optical signals using a slab coupler and phase-shifted waveguide array"
Nature of Dispute: The Parties' dispute regarding this term centers on whether "waveguide multiplexer" should be construed broadly to encompass any optical device that performs wavelength multiplexing on a waveguide, or whether the term must be narrowly limited to one specific type of multiplexer architecture — namely, an arrayed waveguide grating ("AWG").
OWS contends that the claim language itself is broad and uses the open-ended transitional phrase "comprising," which by its well-established legal meaning does not exclude additional or alternative structures. OWS argues that a POSITA would understand "waveguide multiplexer" to refer to any optical device that combines multiple optical signals of different wavelengths onto a single waveguide, regardless of the specific architecture used to achieve that function. OWS further contends that the specification of the '847 Patent expressly describes the AWG as merely "one embodiment" of the claimed waveguide multiplexer and also references Echelle gratings and ring-resonator-based multiplexers as alternative implementations. OWS also argues that nothing in the prosecution history of the '847 Patent narrows the term to an AWG, as no narrowing amendment or argument was made to distinguish prior art on the basis of AWG-specific features.
Lumicore contends that the specification's detailed description focuses predominantly — indeed, almost exclusively — on the AWG embodiment, devoting substantially all of the detailed technical disclosure to the AWG architecture, including the slab coupler geometry, the phase-shifted waveguide array design, and the specific fabrication methods for the AWG. Lumicore argues that the brief, passing references to Echelle gratings and ring-resonator-based multiplexers in the specification do not constitute a sufficient disclosure to support a broader construction. Lumicore further contends that during prosecution of the '847 Patent, OWS (then the applicant) distinguished prior art on the basis of features specific to the AWG architecture, thereby narrowing the scope of the term through prosecution history estoppel or, at minimum, through characterization of the invention as AWG-based.
Key Intrinsic Evidence Cited by OWS:
• Claim 1 language uses the open-ended transitional phrase "comprising," which does not limit the claim to the specific structures described in the specification. See ACCO Brands, Inc. v. Micro Sec. Devices, Inc., 346 F.3d 1075, 1084 (Fed. Cir. 2003).
• '847 Patent, col. 4, ll. 22–28 (describing AWG as "one embodiment of the waveguide multiplexer"); col. 4, ll. 29–35 (referencing Echelle diffraction gratings as "another suitable multiplexer architecture"); col. 4, ll. 36–41 (referencing ring-resonator-based multiplexers as "yet another implementation").
• Prosecution history of the '847 Patent: No narrowing amendment was made to any claim during prosecution that would limit the term "waveguide multiplexer" to an AWG. The claims were allowed without amendment to this term following an Examiner's Interview on October 3, 2018.
Key Intrinsic Evidence Cited by Lumicore:
• '847 Patent, col. 5, l. 1 – col. 14, l. 55 (over nine columns of detailed technical disclosure devoted exclusively to the AWG embodiment, including slab coupler design parameters, waveguide array phase shifts, and fabrication details).
• Prosecution history: Applicant's response to the first Office Action (filed April 17, 2018) allegedly distinguished prior art (Doerr et al., U.S. Patent No. 8,873,963) by arguing that Doerr's multiplexer did not use "a slab coupler and phase-shifted waveguide array arrangement" as described in the pending application.
Key Extrinsic Evidence:
• OWS cites the Declaration of Dr. Caroline Ashford, Professor of Electrical Engineering & Photonics at the Northfield Institute of Technology (D.E. 44, Exhibit 1, ¶¶ 28–47), who opines that a POSITA would understand "waveguide multiplexer" to refer broadly to any optical device that combines multiple wavelengths onto a single waveguide, and that AWGs, Echelle gratings, and ring-resonator-based multiplexers are all well-known types of waveguide multiplexers in the art.
• Lumicore cites the Declaration of Dr. Rajesh Sundaram, Professor of Electrical & Computer Engineering at Pacific Western University (D.E. 48, Exhibit A, ¶¶ 32–55), who opines that a POSITA would understand the term "waveguide multiplexer" in the context of the '847 Patent to refer specifically to an AWG, given the predominant focus of the specification on that architecture and the prosecution history of the patent.
Briefing References: OWS Opening Brief (D.E. 44) §§ II.A; Lumicore Responsive Brief (D.E. 48) §§ III.A; OWS Reply Brief (D.E. 52) §§ II.A; Lumicore Sur-Reply (D.E. 56) §§ II.A.
Disputed Term 2: "integrated on a silicon substrate"
Patent(s): '193 Patent (U.S. Patent No. 10,891,193)
Claim(s): Claims 1, 3, 7, 10, 15, 18
OWS's Proposed Construction: "formed on or within a silicon-based wafer using semiconductor fabrication processes"
Lumicore's Proposed Construction: "monolithically fabricated on a single silicon die without hybrid bonding or heterogeneous integration"
Nature of Dispute: The Parties' dispute regarding this term concerns whether "integrated on a silicon substrate" broadly covers any semiconductor fabrication process that forms photonic components on a silicon wafer — including hybrid integration and heterogeneous integration techniques — or whether the term is limited to monolithic fabrication only, excluding hybrid bonding and heterogeneous integration.
OWS argues that the term "integrated on a silicon substrate" is a broad phrase that encompasses any method of forming photonic and electronic components on a silicon-based wafer using semiconductor fabrication processes. OWS contends that the specification of the '193 Patent discusses "integration on a silicon substrate" in broad terms in the background section, referencing both monolithic integration and hybrid integration approaches as known techniques in the field. OWS emphasizes that the claims do not recite "monolithically" or otherwise exclude hybrid bonding or heterogeneous integration. OWS further contends that a POSITA would understand the term to encompass the full range of integration approaches commonly employed in silicon photonics, including monolithic integration, hybrid bonding (e.g., micro-transfer printing, flip-chip bonding), and heterogeneous integration (e.g., wafer bonding of III-V materials to silicon substrates).
Lumicore contends that the detailed description of the '193 Patent favors monolithic integration and that the specification devotes the vast majority of its technical disclosure to monolithically fabricated transceiver components. Lumicore further argues that during prosecution of the '193 Patent, OWS's responses to Office Actions emphasized the monolithic character of the claimed invention in distinguishing prior art that used hybrid integration techniques. Specifically, Lumicore points to the applicant's response to the second Office Action (filed August 22, 2019), in which the applicant allegedly argued that the claimed transceiver was "integrated on a single silicon substrate" and distinguished prior art (Liang et al., U.S. Patent No. 9,316,785) on the ground that Liang's transceiver required "heterogeneous bonding of III-V gain media" rather than integration "on a silicon substrate." Lumicore contends that this prosecution history narrows the term to exclude hybrid bonding and heterogeneous integration.
Key Intrinsic Evidence Cited by OWS:
• '193 Patent, col. 2, ll. 10–32 (background section discussing "integration on a silicon substrate" broadly and referencing "monolithic integration, hybrid bonding, and heterogeneous integration" as approaches known in the field).
• '193 Patent, col. 3, ll. 45–52 (Summary of the Invention stating that "the present invention relates to a coherent optical transceiver integrated on a silicon substrate" without specifying or requiring monolithic fabrication).
• Claims 1, 10, and 18 of the '193 Patent, none of which recite "monolithically" or otherwise limit the integration approach.
Key Intrinsic Evidence Cited by Lumicore:
• '193 Patent, col. 5, l. 12 – col. 18, l. 40 (detailed description allegedly focused on monolithically fabricated components, including silicon-based modulators, germanium photodetectors formed by selective epitaxy on the silicon substrate, and silicon waveguides).
• Prosecution history: Applicant's response to second Office Action (filed August 22, 2019), allegedly distinguishing Liang et al. on the basis that the claimed transceiver is "integrated on a silicon substrate" in contrast to Liang's heterogeneous bonding approach.
Key Extrinsic Evidence:
• OWS cites the Declaration of Dr. Caroline Ashford (D.E. 44, Exhibit 1, ¶¶ 48–72), who opines that a POSITA would understand "integrated on a silicon substrate" to encompass monolithic, hybrid, and heterogeneous integration techniques, all of which are standard methods for forming photonic components on silicon in the semiconductor industry.
• Lumicore cites the Declaration of Dr. Rajesh Sundaram (D.E. 48, Exhibit A, ¶¶ 56–78) and two IEEE Photonics Journal articles: (1) Thomson et al., "Roadmap on Silicon Photonics," Journal of Optics, vol. 18, no. 7 (2016), and (2) Liang & Bowers, "Recent Progress in Heterogeneous III-V-on-Silicon Photonic Integration," Light: Science & Applications, vol. 6 (2017), both of which Lumicore contends demonstrate that "integration on a silicon substrate" is understood in the art to refer specifically to monolithic fabrication, as opposed to the distinct concepts of "hybrid integration" and "heterogeneous integration."
Briefing References: OWS Opening Brief (D.E. 44) §§ II.B; Lumicore Responsive Brief (D.E. 48) §§ III.B; OWS Reply Brief (D.E. 52) §§ II.B; Lumicore Sur-Reply (D.E. 56) §§ II.B.
Disputed Term 3: "micro-channel heat sink"
Patent(s): '562 Patent (U.S. Patent No. 9,678,562)
Claim(s): Claims 1, 4, 6, 11
OWS's Proposed Construction: "a heat-dissipating structure containing channels with a hydraulic diameter of less than 1 mm"
Lumicore's Proposed Construction: "a closed-loop liquid-cooling system with channels having a hydraulic diameter between 10 µm and 200 µm"
Nature of Dispute: The Parties' dispute regarding this term involves two principal issues: (1) the scope of the "micro-channel" dimension limitation, and (2) whether the term requires a closed-loop liquid-cooling architecture.
As to the first issue, OWS contends that the construction should capture the full scope of "micro-channel" as the term is understood in the relevant art — i.e., channels having a hydraulic diameter of less than 1 mm. OWS relies on the specification of the '562 Patent, which expressly defines "micro-channel" as referring to "channels with a hydraulic diameter of less than approximately 1 mm." OWS further contends that this definition is consistent with well-established technical standards and reference texts, including the ASME classification of micro-channels.
Lumicore contends that the specification's express definition is merely a general introduction and that the operative disclosure of the preferred embodiment specifies channels with a hydraulic diameter in the range of 10 µm to 200 µm. Lumicore argues that the narrower range should control, because the broader definition (< 1 mm) would encompass channels that are orders of magnitude larger than the channels actually described in the specification and would extend the claim scope to conventional "mini-channel" heat sinks that are not the subject of the invention.
As to the second issue, OWS argues that nothing in the claim language requires a "closed-loop" configuration or limits the cooling medium to a liquid. OWS notes that the specification describes multiple cooling media, including liquid coolants, gaseous coolants, and two-phase (evaporative) cooling approaches, and that the claims do not recite "closed-loop" or "liquid-cooling." Lumicore contends that the specification describes liquid coolant circulation in a closed loop as the operative mechanism of the heat sink and that the claims must be construed to require this architecture. Lumicore further argues that a POSITA would understand a "heat sink" in the context of micro-channels to inherently require a liquid cooling medium circulated in a closed-loop configuration.
Key Intrinsic Evidence Cited by OWS:
• '562 Patent, col. 3, ll. 14–19 (defining "micro-channel" as "channels with a hydraulic diameter of less than approximately 1 mm").
• '562 Patent, col. 8, ll. 5–22 (describing "liquid, gas, or two-phase cooling media" as suitable for use in the micro-channel heat sink).
• Claims 1, 4, 6, and 11 of the '562 Patent, none of which recite "closed-loop" or "liquid-cooling."
Key Intrinsic Evidence Cited by Lumicore:
• '562 Patent, col. 6, ll. 30–55 (preferred embodiment describing channels with hydraulic diameters of "between approximately 10 µm and approximately 200 µm").
• '562 Patent, col. 7, ll. 1–28 (describing circulation of liquid coolant through the micro-channels in a "closed-loop recirculating system" with an external pump and heat exchanger).
Key Extrinsic Evidence:
• Both Parties cite the ASME classification of channel sizes (S.G. Kandlikar & W.J. Grande, "Evolution of Microchannel Flow Passages — Thermohydraulic Performance and Fabrication Technology," Heat Transfer Engineering, vol. 24, no. 1, pp. 3–17 (2003)), which defines micro-channels as channels with hydraulic diameters in the range of 10 µm to 200 µm, and "mini-channels" as channels with hydraulic diameters in the range of 200 µm to 3 mm. Lumicore argues this supports its narrower range; OWS argues the specification's express definition of < 1 mm controls over any external standard.
• OWS relies on the Declaration of Dr. Caroline Ashford (D.E. 44, Exhibit 1, ¶¶ 73–92) and technical dictionary definitions of "micro-channel" from The Penguin Dictionary of Electronics (4th ed.) and Sterling Reach Industries Dictionary of Scientific and Technical Terms (6th ed.).
• Lumicore relies on the Declaration of Dr. Rajesh Sundaram (D.E. 48, Exhibit A, ¶¶ 79–101).
Briefing References: OWS Opening Brief (D.E. 44) §§ II.C; Lumicore Responsive Brief (D.E. 48) §§ III.C; OWS Reply Brief (D.E. 52) §§ II.C.
Disputed Term 4: "polarization-diverse grating coupler"
Patent(s): '015 Patent (U.S. Patent No. 11,402,015)
Claim(s): Claims 1, 5, 8, 12, 16
OWS's Proposed Construction: "a grating coupler capable of coupling light of two orthogonal polarization states"
Lumicore's Proposed Construction: "a two-dimensional grating coupler with a polarization-splitting element that simultaneously couples TE and TM modes"
Nature of Dispute: The Parties' dispute regarding this term centers on whether "polarization-diverse grating coupler" encompasses any grating coupler design that handles both polarization states — regardless of whether it uses a two-dimensional grating, a one-dimensional grating with an off-chip polarization rotator, or any other polarization-handling approach — or whether the term requires a specific two-dimensional (2D) grating with a polarization-splitting element that simultaneously couples transverse electric (TE) and transverse magnetic (TM) modes.
OWS argues that the claim language uses broad, functional language that does not restrict the claim to any particular grating geometry or polarization-handling mechanism. OWS points to the specification of the '015 Patent, which describes multiple embodiments of the polarization-diverse grating coupler, including: (1) a one-dimensional (1D) grating coupler used in conjunction with an off-chip polarization beam splitter and rotator (described at col. 5, ll. 10–40), and (2) a two-dimensional (2D) grating coupler with an integrated polarization-splitting element (described at col. 6, ll. 1–45). OWS contends that both embodiments fall within the scope of the claim term and that Lumicore improperly seeks to exclude the 1D embodiment.
Lumicore argues that the title of the '015 Patent itself — "Polarization-Diverse Grating Coupler for Silicon Photonic Transceivers" — Signals that the invention is directed to a specific type of grating coupler. Lumicore contends that the detailed description of the '015 Patent focuses on the 2D grating coupler embodiment as the inventive contribution and that the 1D grating embodiment is described only as background or prior art. Lumicore further contends that during prosecution, the applicant narrowed the claims to a 2D grating coupler implementation by distinguishing prior art that used 1D grating couplers with separate polarization-handling optics.
Key Intrinsic Evidence Cited by OWS:
• Claims 1, 5, 8, 12, and 16 of the '015 Patent, which use broad functional language (e.g., "a polarization-diverse grating coupler configured to couple light of two orthogonal polarization states") without specifying a 2D grating or a polarization-splitting element.
• '015 Patent, col. 5, ll. 10–40 (describing 1D grating with off-chip polarization rotator as one embodiment).
• '015 Patent, col. 6, ll. 1–45 (describing 2D grating with integrated polarization splitter as another embodiment).
Key Intrinsic Evidence Cited by Lumicore:
• Title of '015 Patent: "Polarization-Diverse Grating Coupler for Silicon Photonic Transceivers."
• '015 Patent, col. 6, ll. 1–45 and Figs. 2A–2D (extensive disclosure of 2D grating embodiment).
• Prosecution history: Applicant's response to first Office Action (filed March 15, 2021), allegedly distinguishing Taillaert et al. (U.S. Patent No. 7,065,272) on the ground that Taillaert's 1D grating coupler does not achieve "polarization diversity" within the grating coupler itself.
Key Extrinsic Evidence:
• OWS cites the Supplemental Declaration of Dr. Caroline Ashford (D.E. 52, Exhibit 1, ¶¶ 15–38), who opines that a POSITA would understand "polarization-diverse grating coupler" to encompass any grating coupler that can handle two orthogonal polarization states, regardless of the specific mechanism.
• Lumicore cites the Declaration of Dr. Rajesh Sundaram (D.E. 48, Exhibit A, ¶¶ 102–128) and photonics textbook definitions from R. Halir et al., "Waveguide Grating Coupler Design: An Overview," in Handbook of Silicon Photonics (Aldermere Partners LLC, 2d ed. 2019).
Briefing References: OWS Opening Brief (D.E. 44) §§ II.D; Lumicore Responsive Brief (D.E. 48) §§ III.D; OWS Reply Brief (D.E. 52) §§ II.D; Lumicore Sur-Reply (D.E. 56) §§ II.C.
Disputed Term 5: "Coherent detection module"
Patent(s): '193 Patent (U.S. Patent No. 10,891,193)
Claim(s): Claims 3, 7
OWS's Proposed Construction: "a module configured to detect an optical signal using coherent detection, comprising a local oscillator and one or more photodetectors"
Lumicore's Proposed Construction: "a module that performs intradyne coherent detection using a tunable local oscillator laser, a 90-degree optical hybrid, and balanced photodetectors, all integrated on the same silicon die as the transceiver"
Nature of Dispute: The Parties' dispute regarding this term involves the scope of the coherent detection architecture required by the claim. Lumicore seeks to narrow the term to a highly specific architecture requiring: (a) intradyne detection (as opposed to homodyne or heterodyne detection); (b) a tunable local oscillator laser; (c) a 90-degree optical hybrid; (d) balanced photodetectors (as opposed to single-ended photodetectors); and (e) monolithic integration on the same silicon die as the transceiver.
OWS argues that the term "coherent detection module" should encompass all forms of coherent detection, including homodyne, heterodyne, and intradyne detection, without requiring specific sub-components (such as a 90-degree optical hybrid or balanced photodetectors) or monolithic integration on the same die. OWS contends that the claim language requires only a "module configured to detect an optical signal using coherent detection, comprising a local oscillator and one or more photodetectors," and that Lumicore's proposed construction improperly imports numerous limitations from the preferred embodiment into the claim.
OWS further notes that the specification describes intradyne detection as one embodiment but also discusses homodyne and heterodyne detection as "alternative approaches to coherent reception" in the background section. OWS argues that the specification's disclosure of multiple coherent detection approaches supports a broad construction.
Lumicore contends that the specification's detailed description overwhelmingly focuses on the intradyne detection architecture with the specific sub-components identified in its proposed construction, and that a POSITA reading the patent would understand the term to be limited accordingly.
Note on Doctrine of Equivalents Relevance: This term is relevant to OWS's doctrine of equivalents ("DOE") contentions for Claims 3 and 7 of the '193 Patent. OWS's infringement contentions include an assertion that, even if Lumicore's accused detection architecture does not literally satisfy this claim limitation as construed, it performs substantially the same function, in substantially the same way, to achieve substantially the same result as the claimed "coherent detection module." The construction of this term therefore has significant implications for the scope of OWS's DOE analysis and for any prosecution history estoppel defense that Lumicore may assert under Festo Corp. v. Fenmore & Co., 535 U.S. 722 (2002).
Prosecution History Note: During prosecution of the '193 Patent, Claims 3 and 7 were amended to add the "coherent detection module" limitation in response to a rejection under 35 U.S.C. § 102(a)(1) over Takahashi et al. ("Single-Chip Coherent Receiver Integrated with a Polarization-Diversity 90-Degree Optical Hybrid on InP," IEEE Photonics Technology Letters, vol. 26, no. 6, pp. 560–563, March 2014). The scope of the narrowing amendment and its effect on prosecution history estoppel is disputed. OWS contends the amendment was directed to adding a coherent detection module as a component of the claimed transceiver, not to limiting the type of coherent detection performed. Lumicore contends the amendment was specifically directed to distinguishing the intradyne coherent detection architecture of the applicant's invention from the prior art, thereby narrowing the claim scope and giving rise to prosecution history estoppel that forecloses OWS's DOE contentions.
Key Intrinsic Evidence Cited by OWS:
• '193 Patent, col. 2, ll. 40–58 (background section discussing homodyne, heterodyne, and intradyne coherent detection as known approaches).
• '193 Patent, Claims 3 and 7, which recite "a coherent detection module" without specifying the type of coherent detection or the specific sub-components.
• Prosecution history: Amendment filed June 12, 2020, adding "coherent detection module" language to Claims 3 and 7. OWS contends the remarks accompanying the amendment stated only that the claimed transceiver includes a "coherent detection module," without limiting the detection type.
Key Intrinsic Evidence Cited by Lumicore:
• '193 Patent, col. 10, ll. 15–55 and Figs. 9A–9C (detailed description of intradyne coherent detection module with tunable local oscillator laser, 90-degree optical hybrid, and balanced photodetectors).
• Prosecution history: Applicant's remarks accompanying June 12, 2020 amendment, allegedly distinguishing Takahashi on the basis that Takahashi's receiver was formed on InP (not silicon) and that the claimed invention provides a "coherent detection module" that is "integrated on the silicon substrate."
Key Extrinsic Evidence:
• OWS cites the Declaration of Dr. Caroline Ashford (D.E. 44, Exhibit 1, ¶¶ 93–118).
• Lumicore cites the Declaration of Dr. Rajesh Sundaram (D.E. 48, Exhibit A, ¶¶ 129–156).
Briefing References: OWS Opening Brief (D.E. 44) §§ II.E; Lumicore Responsive Brief (D.E. 48) §§ III.E; OWS Reply Brief (D.E. 52) §§ II.E; Lumicore Sur-Reply (D.E. 56) §§ II.D.
Disputed Term 6: "two-dimensional sub-wavelength grating"
Patent(s): '015 Patent (U.S. Patent No. 11,402,015)
Claim(s): Claim 12
OWS's Proposed Construction: "a grating structure with periodicity in two dimensions where the grating period is smaller than the wavelength of the coupled light"
Lumicore's Proposed Construction: "a grating etched into the silicon waveguide layer with a two-dimensional periodic pattern having a period in both dimensions smaller than the operational wavelength, where the grating features are formed by a single etch step"
Nature of Dispute: The Parties' dispute regarding this term involves two issues: (1) whether the "sub-wavelength" limitation requires the grating period in both dimensions to be smaller than the operational wavelength, and (2) whether the construction should include a fabrication-method limitation requiring the grating features to be formed by a single etch step.
As to the first issue, OWS contends that the claim language — "two-dimensional sub-wavelength grating" — requires only that the grating have periodicity in two dimensions and that "the grating period" (taken as a whole) be smaller than the wavelength of the coupled light. OWS argues the term does not require that each individual dimensional period independently satisfy the sub-wavelength condition. Lumicore contends that a "two-dimensional sub-wavelength grating" requires sub-wavelength periodicity in both dimensions, and that a grating with a sub-wavelength period in only one dimension would not qualify.
As to the second issue, Lumicore seeks to add a limitation requiring the grating features to be "formed by a single etch step." OWS argues that the specification does not require a single etch step and that the claim language does not impose any restrictions on the fabrication method used to create the grating. OWS contends that importing a fabrication-method limitation into the claim is improper, particularly where the claim is directed to a structural product, not a method of manufacturing. Lumicore argues the specification teaches the single etch step as the only disclosed fabrication approach, and that without this limitation, the claim would encompass structures that a POSITA would not understand to be "two-dimensional sub-wavelength gratings."
Doctrine of Equivalents Relevance: This term is central to OWS's DOE contentions for Claim 12 of the '015 Patent. During prosecution, a narrowing amendment was made to Claim 12 to overcome a rejection under 35 U.S.C. § 103 combining Bergmann (U.S. Patent No. 8,412,007) with Simonsen (PCT/EP2015/071234). The scope of the surrender resulting from that amendment and its implications for prosecution history estoppel under Festo are disputed between the Parties.
Key Intrinsic Evidence Cited by OWS:
• Claim 12 of the '015 Patent, which recites "a two-dimensional sub-wavelength grating" without specifying that both dimensions must be sub-wavelength and without reciting any fabrication method.
• '015 Patent, col. 8, ll. 25–40 (describing grating fabrication using either a "single etch step" or a "multi-step etch process").
Key Intrinsic Evidence Cited by Lumicore:
• '015 Patent, col. 7, ll. 50–65 and Fig. 4A (describing a 2D periodic pattern with periods Λx and Λy, both stated to be "less than the operational wavelength λ").
• '015 Patent, col. 8, ll. 25–32 (describing the "preferred" fabrication approach using a "single deep-UV lithography and etch step").
• Prosecution history: Amendment to Claim 12 filed September 30, 2021, adding "sub-wavelength" limitation to overcome § 103 rejection combining Bergmann and Simonsen.
Key Extrinsic Evidence:
• OWS cites the Supplemental Declaration of Dr. Caroline Ashford (D.E. 52, Exhibit 1, ¶¶ 39–58).
• Lumicore cites the Declaration of Dr. Rajesh Sundaram (D.E. 48, Exhibit A, ¶¶ 157–178).
Briefing References: OWS Opening Brief (D.E. 44) §§ II.F; Lumicore Responsive Brief (D.E. 48) §§ III.F; OWS Reply Brief (D.E. 52) §§ II.F.
Disputed Term 7: "low insertion loss"
Patent(s): '847 Patent (U.S. Patent No. 10,234,847)
Claim(s): Claims 1, 14
OWS's Proposed Construction: "insertion loss that is reduced compared to prior art waveguide multiplexers" (or, alternatively, plain and ordinary meaning without a specific numerical threshold)
Lumicore's Proposed Construction: "insertion loss of less than 1.5 dB per channel across the operating wavelength band"
Nature of Dispute: Lumicore seeks to import a specific numerical limitation — less than 1.5 dB per channel — from the specification's description of the performance characteristics of the preferred embodiment. OWS argues that the claim uses the qualitative, relative term "low insertion loss," which a POSITA would understand in context to mean insertion loss that is reduced or improved compared to prior art waveguide multiplexers, without being anchored to a specific numerical threshold.
OWS contends that importing a specific dB value from the preferred embodiment improperly reads a preferred-embodiment limitation into the claim. See Phillips v. AWH Corp., 415 F.3d 1303, 1323 (Fed. Cir. 2005) (en banc) ("[I]t is not enough that the only embodiment, or all of the embodiments, contain a particular limitation" to justify reading that limitation into the claim). OWS further notes that the specification uses "low insertion loss" as a relative term, comparing the performance of the claimed multiplexer to prior art devices, and never defines "low insertion loss" as requiring a specific dB threshold.
Lumicore contends that the term "low insertion loss" is indefinite unless given a specific numerical boundary, and that the specification provides such a boundary by repeatedly describing the performance of the preferred embodiment as achieving "insertion loss of less than approximately 1.5 dB per channel." Lumicore argues that a POSITA would understand "low insertion loss" to be defined by this specification disclosure and that, absent a numerical construction, the term would be impermissibly vague and subjective.
Key Intrinsic Evidence Cited by OWS:
• '847 Patent, Abstract and col. 1, ll. 50–60 (using "low insertion loss" as a relative descriptor comparing the invention to prior art).
• '847 Patent, col. 14, ll. 30–45 (describing measured insertion loss of "less than approximately 1.5 dB per channel" for "one embodiment" of the waveguide multiplexer).
• Claims 1 and 14 of the '847 Patent, which recite "low insertion loss" without specifying a numerical threshold.
Key Intrinsic Evidence Cited by Lumicore:
• '847 Patent, col. 14, ll. 30–45 (same passage, relied upon by Lumicore as a definitional disclosure).
• '847 Patent, col. 3, ll. 5–15 (stating that "it is an object of the present invention to provide a waveguide multiplexer with insertion loss of less than approximately 1.5 dB per channel").
Key Extrinsic Evidence:
• OWS cites the Declaration of Dr. Caroline Ashford (D.E. 44, Exhibit 1, ¶¶ 119–135), who opines that a POSITA would understand "low insertion loss" as a relative, qualitative term without a fixed numerical meaning.
• Lumicore cites the Declaration of Dr. Rajesh Sundaram (D.E. 48, Exhibit A, ¶¶ 179–195), who opines that a POSITA would understand "low insertion loss" to require a specific numerical threshold and that the specification provides that threshold as 1.5 dB per channel.
Briefing References: OWS Opening Brief (D.E. 44) §§ II.G; Lumicore Responsive Brief (D.E. 48) §§ III.G; OWS Reply Brief (D.E. 52) §§ II.G.
Disputed Term 8: "embedded"
Patent(s): '562 Patent (U.S. Patent No. 9,678,562)
Claim(s): Claims 1, 4, 6, 11
OWS's Proposed Construction: "formed within or enclosed by the photonic integrated circuit structure"
Lumicore's Proposed Construction: "fully enclosed within the silicon substrate of the photonic integrated circuit, with no exposed surfaces"
Nature of Dispute: The Parties' dispute regarding this term concerns whether "embedded" requires complete enclosure with no exposed channel surfaces, as Lumicore contends, or whether the term requires only that the micro-channels be formed within the photonic integrated circuit ("PIC") structure without requiring zero exposed surfaces.
Lumicore argues that the ordinary meaning of "embedded" connotes complete enclosure and that a structure with exposed surfaces is not "embedded" but merely "recessed" or "etched." Lumicore further contends that the specification supports its construction, because the disclosed micro-channels are formed within the silicon substrate and are sealed by a cap layer, resulting in fully enclosed channels with no exposed surfaces.
OWS argues that the term "embedded" requires only that the micro-channels be formed within the PIC structure, meaning they are integrated into and enclosed by the surrounding material of the PIC, but not necessarily that every surface of every channel be completely sealed with zero exposed areas. OWS points to the specification's description of various embodiments, including an embodiment in which the micro-channels are partially exposed at inlet and outlet ports for coolant flow. OWS contends that Lumicore's construction would render the claimed micro-channel heat sink inoperable, because a completely sealed channel with no exposed surfaces could not admit or discharge coolant.
OWS further argues that the specification distinguishes the claimed "embedded" micro-channel heat sink from external or surface-mounted heat sinks, not from heat sinks with inlet/outlet ports. OWS contends that Lumicore's construction conflates "embedded" with "hermetically sealed," a term not used in the claims or specification.
Key Intrinsic Evidence Cited by OWS:
• '562 Patent, col. 5, ll. 20–35 (describing micro-channels "embedded within the photonic integrated circuit structure" and sealed by a cap layer, with "inlet and outlet ports" for coolant flow).
• '562 Patent, Fig. 3B (cross-sectional view showing micro-channels within the silicon substrate with a cap layer and visible inlet/outlet openings).
• Claims 1, 4, 6, and 11 of the '562 Patent, which recite "embedded" without requiring "no exposed surfaces" or "fully enclosed."
Key Intrinsic Evidence Cited by Lumicore:
• '562 Patent, col. 5, ll. 36–42 (describing the cap layer as "sealing the micro-channels within the silicon substrate").
• '562 Patent, col. 2, ll. 15–25 (background section criticizing prior art "surface-mounted" heat sinks and distinguishing them from the "embedded" approach of the invention).
Key Extrinsic Evidence:
• OWS cites the Declaration of Dr. Caroline Ashford (D.E. 44, Exhibit 1, ¶¶ 136–148).
• Lumicore cites the Declaration of Dr. Rajesh Sundaram (D.E. 48, Exhibit A, ¶¶ 196–212) and dictionary definitions of "embedded" from Aldermere Partners LLC Dictionary (11th ed.) ("enclosed closely in or as if in a matrix") and The American Heritage Dictionary of the English Language (5th ed.) ("to fix firmly in a surrounding mass").
Briefing References: OWS Opening Brief (D.E. 44) §§ II.H; Lumicore Responsive Brief (D.E. 48) §§ III.H; OWS Reply Brief (D.E. 52) §§ II.H.
Disputed Term 9: "high-bandwidth"