[slide 1]
Claim Construction Hearing — Optiwave Semiconductor Corp. v. Lumicore Technologies, Inc.
Claim Construction Hearing — March 14, 2025
Optiwave Semiconductor Corp. v. Lumicore Technologies, Inc.
Case No. 2:24-cv-00319-JRG
United States District Court for the Eastern District of Texas
Before the Honorable Judge James R. Gilstrap
Presented by Calderwood & Harkness LLP on behalf of Plaintiff Optiwave Semiconductor Corp.
Alan Ngo, Responsible Partner; Marcus Delgado, Billing Partner; Wendy Schultz, Lead Associate; Omar Siddiqui, Working Associate
Local Counsel: James Callahan, Whitmore & Callahan LLP, Tyler, TX
[slide 2]
Agenda / Roadmap
I. Technology Tutorial — Silicon Photonics Overview
II. The Asserted Patents — Brief Overview
III. Person of Ordinary Skill in the Art (POSITA)
IV. Disputed Claim Terms — Overview of 14 Terms (12 Remaining in Dispute)
V. Detailed Analysis of Key Disputed Terms: (A) 'waveguide multiplexer' ('847 Patent), (B) 'integrated on a silicon substrate' ('193 Patent), (C) 'micro-channel heat sink' ('562 Patent), (D) 'polarization-diverse grating coupler' ('015 Patent), (E) Additional Disputed Terms
VI. Summary and Proposed Constructions
[slide 3]
Technology Tutorial: What Is Silicon Photonics?
Silicon photonics: integration of optical components on a silicon chip using standard semiconductor fabrication processes
Enables high-speed data transmission using light rather than electrical signals
Critical for hyperscale data-center interconnects — transmitting massive volumes of data between servers and networking equipment
Key advantage: leverages existing CMOS manufacturing infrastructure for cost-effective, high-volume production
[slide 4]
Technology Tutorial: Optical Transceiver Modules
Optical transceiver module: a device that converts electrical data signals to optical signals (and vice versa) for transmission over fiber-optic cable
Key components: laser source, modulator, photodetector, waveguide multiplexer/demultiplexer, grating couplers, thermal management elements
Industry standards: 400G-ZR, 800G-DR8, 1600G-LR — designating data rates and reach specifications
OWS products: OWS-400ZR, OWS-800XR, OWS-1600DR module families
Lumicore accused products: LumiLink 400G-ZR+, LumiLink 800G-DR8, LumiEdge 1600G-LR
[slide 5]
Technology Tutorial: Waveguide Multiplexing
Wavelength-division multiplexing (WDM): combining multiple optical signals of different wavelengths onto a single waveguide for simultaneous transmission
Arrayed waveguide gratings (AWGs) are one type of waveguide multiplexer — but not the only type
Other architectures include echelle gratings, Mach-Zehnder interferometer cascades, and ring-resonator arrays
Insertion loss: the reduction in signal power caused by the multiplexer — lower is better
The '847 Patent addresses a multi-channel silicon photonic waveguide multiplexer achieving low insertion loss
[slide 6]
Technology Tutorial: Coherent Optical Transceivers
Coherent detection: a technique that encodes information in the amplitude, phase, and polarization of the optical signal — enabling much higher data rates
Requires a local oscillator laser, optical hybrid mixer, and balanced photodetectors
Integration on a silicon substrate: fabricating all components on a single silicon chip or platform
The '193 Patent covers a high-bandwidth coherent optical transceiver integrated on a silicon substrate
[slide 7]
Technology Tutorial: Thermal Management in Photonic Integrated Circuits
Photonic integrated circuits (PICs) generate heat that degrades performance — wavelength drift, increased noise
Micro-channel heat sinks: small channels embedded in or attached to the chip through which a coolant flows to remove heat
Hydraulic diameter: a key dimensional parameter characterizing the channel size
The '562 Patent teaches embedded micro-channel heat sinks for thermal management of PICs
Originally assigned to Solara Optics, Inc.; acquired by OWS via asset purchase agreement on June 15, 2018 for $34.5 million (12 patents total)
[slide 8]
Technology Tutorial: Polarization-Diverse Grating Couplers
Grating coupler: a structure etched onto the chip surface that redirects light from an optical fiber into the on-chip waveguide (and vice versa)
Polarization diversity: the ability to handle light in two orthogonal polarization states (TE and TM modes)
Critical because fiber-optic signals have random, varying polarization states
The '015 Patent covers a polarization-diverse grating coupler for silicon photonic transceivers
Filed August 30, 2019; issued August 2, 2022; shares Provisional App. No. 62/499,117 with the '193 Patent
[slide 9]
The Asserted Patents — Overview
'847 Patent — U.S. 10,234,847: 'Multi-Channel Silicon Photonic Waveguide Multiplexer with Low Insertion Loss' (Filed Sept. 14, 2016; Issued Mar. 19, 2019)
'193 Patent — U.S. 10,891,193: 'High-Bandwidth Coherent Optical Transceiver Integrated on Silicon Substrate' (Filed Apr. 7, 2017; Issued Jan. 12, 2021)
'562 Patent — U.S. 9,678,562: 'Method for Thermal Management of Photonic Integrated Circuits Using Embedded Micro-Channel Heat Sinks' (Filed Nov. 22, 2014; Issued June 13, 2017)
'015 Patent — U.S. 11,402,015: 'Polarization-Diverse Grating Coupler for Silicon Photonic Transceivers' (Filed Aug. 30, 2019; Issued Aug. 2, 2022)
All four are utility patents; all maintenance fees current; no IPR petitions filed to date
'562 and '847 Patents are in the same family (continuation relationship)
'193 and '015 Patents share common Provisional App. No. 62/499,117
[slide 10]
The Asserted Patents — Patent Family Relationships
'562 Patent (filed Nov. 2014) → continuation → '847 Patent (filed Sept. 2016)
Provisional App. 62/499,117 (filed Apr. 7, 2017) → '193 Patent (filed Apr. 7, 2017) and '015 Patent (filed Aug. 30, 2019)
Two distinct family lineages share a common technology platform: silicon photonics for data-center interconnects
[slide 11]
Person of Ordinary Skill in the Art (POSITA)
OWS's Proposed POSITA: A person with an M.S. or Ph.D. in electrical engineering or photonics and at least 3 years of experience in silicon-photonic integrated circuit design
Lumicore's Proposed POSITA: [Defendant's proposed definition — as stated in their responsive brief]
Dr. Caroline Ashford's declaration (Nov. 15, 2024) supports OWS's definition, grounded in the level of skill reflected in the patent specifications and the state of the art at the time of filing
Dr. Rajesh Sundaram's competing POSITA definition addressed in Dr. Ashford's supplemental declaration (Dec. 20, 2024)
[slide 12]
Overview of Disputed Claim Construction Terms
14 terms identified in Joint Claim Construction Statement (Oct. 28, 2024)
2 terms agreed upon by the parties (constructions stipulated)
12 terms remain in dispute — presented in the Joint Claim Construction Chart (final, Jan. 15, 2025)
Key disputed terms (addressed in depth): (1) 'waveguide multiplexer' ('847 Patent), (2) 'integrated on a silicon substrate' ('193 Patent), (3) 'micro-channel heat sink' ('562 Patent), (4) 'polarization-diverse grating coupler' ('015 Patent)
Plus 8 additional disputed terms addressed in sequence
[slide 13]
Disputed Term #1: 'waveguide multiplexer' — Competing Constructions
Patent: '847 Patent (U.S. 10,234,847), Claims 1, 3, 5, 9, 14
OWS's Construction: 'an optical device that combines multiple optical signals of different wavelengths onto a single waveguide'
Lumicore's Construction: 'an arrayed waveguide grating that combines optical signals using a slab coupler and phase-shifted waveguide array'
Core dispute: Lumicore seeks to limit the term to a single species (AWG) rather than the genus (any waveguide multiplexer)
[slide 14]
'waveguide multiplexer' — Claim Language
Claim 1 of the '847 Patent: 'A multi-channel silicon photonic device comprising: a waveguide multiplexer configured to combine a plurality of optical signals of different wavelengths onto a single output waveguide…'
The claims do not recite 'arrayed waveguide grating,' 'slab coupler,' or 'phase-shifted waveguide array'
Dependent claims add specific structural limitations — supporting claim differentiation
[slide 15]
'waveguide multiplexer' — Specification Evidence
Specification discloses multiple embodiments of waveguide multiplexers — not limited to AWGs
Embodiment 1: Arrayed waveguide grating (AWG) — described as 'one example' or 'in one embodiment'
Embodiment 2: Echelle diffraction grating — described as an alternative
Embodiment 3: Cascaded Mach-Zehnder interferometers — described as another alternative
Specification states: 'Various multiplexer architectures may be employed without departing from the scope of the invention'
No disclaimer or disavowal of any multiplexer type
[slide 16]
'waveguide multiplexer' — Prosecution History
During prosecution, examiner did not require narrowing of 'waveguide multiplexer' to any specific architecture
No narrowing amendments were made to this term
No statements during prosecution limited 'waveguide multiplexer' to AWG or any particular structure
Prosecution history is silent on any disclaimer — no basis for Lumicore's narrow reading
[slide 17]
'waveguide multiplexer' — Extrinsic Evidence
Technical dictionaries define 'waveguide multiplexer' broadly as a device that combines multiple optical signals onto a single waveguide
IEEE standards and textbooks use the term generically — not limited to AWGs
Dr. Ashford's declaration (Nov. 15, 2024): a POSITA would understand the term to encompass any architecture that combines multi-wavelength signals onto a single waveguide
Lumicore's own product literature uses 'waveguide multiplexer' generically
[slide 18]
'waveguide multiplexer' — Why Lumicore's Construction Fails
Lumicore improperly imports a preferred embodiment into the claims (violates Phillips v. AWH Corp.)
Lumicore's construction reads dependent claim limitations into independent Claim 1 — violates claim differentiation doctrine
No disclaimer or disavowal in the prosecution history supports the narrow reading
If adopted, Lumicore's construction would render the alternative embodiments disclosed in the specification superfluous
OWS's construction: 'an optical device that combines multiple optical signals of different wavelengths onto a single waveguide'
[slide 19]
Disputed Term #2: 'integrated on a silicon substrate' — Competing Constructions
Patent: '193 Patent (U.S. 10,891,193), Claims 1, 3, 7, 10, 15, 18
OWS's Construction: 'formed on or within a silicon-based wafer using semiconductor fabrication processes'
Lumicore's Construction: 'monolithically fabricated on a single silicon die without hybrid bonding or heterogeneous integration'
Core dispute: Lumicore seeks to exclude hybrid integration approaches — limiting the patent to monolithic-only fabrication
[slide 20]
'integrated on a silicon substrate' — Claim Language
Claim 1 of the '193 Patent: 'A high-bandwidth coherent optical transceiver integrated on a silicon substrate, comprising…'
The claim does not recite 'monolithically fabricated,' 'single silicon die,' or 'without hybrid bonding'
The use of 'integrated on' rather than 'monolithically integrated on' is deliberate and meaningful
[slide 21]
'integrated on a silicon substrate' — Specification Evidence
Specification describes both monolithic and heterogeneous integration approaches as within the scope of the invention
Embodiment 1: Monolithic integration — all components fabricated on a single silicon wafer
Embodiment 2: Heterogeneous integration — III-V laser sources bonded to silicon platform
Specification states integration 'on' a substrate encompasses components 'formed on or within' the substrate using 'various semiconductor fabrication approaches'
No disclaimer of heterogeneous integration
[slide 22]
'integrated on a silicon substrate' — Prosecution History
The '193 Patent shares Provisional App. No. 62/499,117 (filed April 7, 2017) with the '015 Patent
During prosecution, the examiner did not require the applicant to distinguish between monolithic and heterogeneous integration
The narrowing amendment made during prosecution related to the 'coherent detection module' limitation — not to 'integrated on a silicon substrate'
No prosecution history estoppel attaches to this term
[slide 23]
'integrated on a silicon substrate' — Why Lumicore's Construction Fails
Lumicore's construction excludes a disclosed embodiment (heterogeneous integration) from the claims
The claim language does not use 'monolithically' — Lumicore adds words that are not there
Industry usage of 'integrated on a silicon substrate' encompasses both monolithic and hybrid approaches
Dr. Ashford's declaration confirms a POSITA would not limit the term to monolithic fabrication
OWS's construction: 'formed on or within a silicon-based wafer using semiconductor fabrication processes'
[slide 24]
Disputed Term #3: 'micro-channel heat sink' — Competing Constructions
Patent: '562 Patent (U.S. 9,678,562), Claims 1, 4, 6, 11
OWS's Construction: 'a heat-dissipating structure containing channels with a hydraulic diameter of less than 1 mm'
Lumicore's Construction: 'a closed-loop liquid-cooling system with channels having a hydraulic diameter between 10 µm and 200 µm'
Core dispute: Lumicore adds two limitations not in the claims — (1) 'closed-loop liquid-cooling system' and (2) a narrow channel-size range of 10–200 µm
[slide 25]
'micro-channel heat sink' — Claim Language
Claim 1 of the '562 Patent: 'A method for thermal management of a photonic integrated circuit, comprising: forming a micro-channel heat sink embedded within a substrate…'
The claim does not recite 'closed-loop,' 'liquid-cooling system,' or any specific hydraulic diameter range
The term 'micro-channel' is a well-understood term in the art — generally referring to channels with sub-millimeter dimensions
[slide 26]
'micro-channel heat sink' — Specification Evidence
Specification defines 'micro-channel' as channels with dimensions 'on the order of micrometers to sub-millimeter' — consistent with hydraulic diameter < 1 mm
Specification discloses both closed-loop and open-loop (e.g., evaporative) cooling configurations
Preferred embodiment describes channels with dimensions in the 50–500 µm range — but does not limit the invention to this range
No language in the specification restricts 'micro-channel heat sink' to only liquid-cooling or to the 10–200 µm range Lumicore proposes
[slide 27]
'micro-channel heat sink' — Prosecution History & Prior Art Context
During prosecution, the term was not amended or narrowed
Lumicore's invalidity contentions cite the Bergmann patent (U.S. 8,412,007) and Dr. Li Wei's conference paper ('Thermal Solutions for PICs,' OFC 2013) — but these references do not dictate the claim's scope
The prosecution history contains no disclaimer of broader micro-channel dimensions
The '562 Patent's priority date (November 22, 2014) is well-established; maintenance fees are current
[slide 28]
'micro-channel heat sink' — Why Lumicore's Construction Fails
Lumicore improperly imports 'closed-loop liquid-cooling' — a limitation not found in the claims
Lumicore's 10–200 µm range is narrower than even the preferred embodiment described in the specification
The specification discloses open-loop configurations — Lumicore's 'closed-loop' requirement would exclude them
Technical dictionaries and Dr. Ashford's declaration confirm 'micro-channel' is broadly understood as sub-millimeter
OWS's construction: 'a heat-dissipating structure containing channels with a hydraulic diameter of less than 1 mm'
[slide 29]
Disputed Term #4: 'polarization-diverse grating coupler' — Competing Constructions
Patent: '015 Patent (U.S. 11,402,015), Claims 1, 5, 8, 12, 16
OWS's Construction: 'a grating coupler capable of coupling light of two orthogonal polarization states'
Lumicore's Construction: 'a two-dimensional grating coupler with a polarization-splitting element that simultaneously couples TE and TM modes'
Core dispute: Lumicore adds structural limitations (two-dimensional, polarization-splitting element, simultaneity) not required by the claim language
[slide 30]
'polarization-diverse grating coupler' — Claim Language
Claim 1 of the '015 Patent: 'A silicon photonic transceiver comprising: a polarization-diverse grating coupler configured to couple light of a first polarization state and light of a second polarization state orthogonal to the first polarization state…'
The claim specifies function — coupling two orthogonal polarization states — not a specific structural implementation
No mention of 'two-dimensional,' 'polarization-splitting element,' or 'simultaneously' in the claim language
[slide 31]
'polarization-diverse grating coupler' — Specification Evidence
Specification discloses multiple embodiments of polarization-diverse grating couplers:
Embodiment 1: Two-dimensional (2D) grating coupler with integrated polarization splitting
Embodiment 2: Pair of one-dimensional (1D) grating couplers with an external polarization beam splitter