Contract analysis

I. INTRODUCTION AND SCOPE OF ENGAGEMENT A. Identification of the Expert

1. My name is Dr. Caroline Ashford. I am a Professor of Electrical Engineering & Photonics at the Northfield Institute of Technology ("NIT") in Evanston, Illinois. I have been retained by the law firm of Calderwood & Harkness LLP on behalf of Plaintiff Optiwave Semiconductor Corp. ("OWS" or "Plaintiff") as a technical expert in connection with this patent infringement action. My retention agreement with Calderwood &

2. I am being compensated at a rate of $950 per hour for all time spent on this engagement, including but not limited to document review, analysis, report preparation, deposition preparation, deposition testimony, trial preparation, and trial testimony. My compensation is not contingent in any way on the opinions I express or the outcome of this litigation.

3. I have been asked to serve as a technical expert on infringement of four United States utility patents asserted by OWS against Defendant Lumicore Technologies, Inc. ("Lumicore" or "Defendant") in this action. Specifically, I have been asked to analyze whether certain products manufactured, sold, offered for sale, used, and/or imported by Lumicore infringe the asserted claims of U.S. Patent Nos. 10,234,847 (the "'8

4. Calderwood & Harkness LLP, through its partners and associates Alan Ngo (Responsible Partner), Wendy Schultz (Lead Associate), and Omar Siddiqui (Working Associate), and in coordination with local counsel Whitmore & Callahan LLP (James "Jim" Callahan, Local Counsel), has asked me to analyze and provide my expert opinions on the following issues: (a) Whether certain products manufactured, sold, offered for sale, us

5. My analysis covers all three accused product lines identified in OWS's P.R. 3-1 Infringement Contentions served September 16, 2024: the LumiLink 400G-ZR+ transceiver module, the LumiLink 800G-DR8 transceiver module, and the LumiEdge 1600G-LR transceiver module (collectively, the "Accused Products"). C. Summary of Opinions

6. Based on my education, training, professional experience, my review and analysis of the technical materials and evidence described in Section III of this report, and my understanding of the applicable legal standards as explained to me by counsel, it is my opinion, to a reasonable degree of scientific and engineering certainty, that: (a) LumiLink 400G-ZR+ infringes the asserted claims of the '847 Patent (Claims 1,

7. These opinions are based on my extensive review and analysis of the physical teardown data from Benchmark Semiconductor Analysis, LLC, Lumicore's own internal design documents and engineering specifications produced in discovery, deposition testimony from key Lumicore and OWS witnesses, the prosecution histories of each asserted patent, and the complete intrinsic records of the four patents-in-suit. The detailed b

8. I reserve the right to supplement or amend this report based on additional discovery, including but not limited to documents and testimony produced after the date of this report. In particular, I reserve the right to revise my opinions as necessary following the Court's claim construction order arising from the Markman hearing currently scheduled for March 14, 2025, before the Honorable James R. Gilstrap. This rep

9. I further reserve the right to respond to the rebuttal opinions of Lumicore's designated technical expert, Dr. Rajesh Sundaram of Pacific Western University, whose report has not yet been served as of the date of this report. I understand that Lumicore's expert rebuttal report is due on or about July 15, 2025, and I will prepare a rebuttal report addressing Dr. Sundaram's opinions to the extent they conflict with

10. I also reserve the right to supplement my opinions based on any evidence developed through additional depositions, expert reports on damages, or other proceedings in this case. Nothing in this report should be interpreted as a waiver of any opinion or position not expressly addressed herein.

II. QUALIFICATIONS AND BACKGROUND A. Education

11. I hold a Ph.D. in Electrical Engineering with a specialization in Integrated Photonics from the Northfield Institute of Technology, which I received in 1999. My doctoral dissertation, entitled "Monolithic Integration of Silicon Photonic Waveguide Arrays for Dense Wavelength-Division Multiplexing Applications," was supervised by Professor Harold V. Steinberg and was recognized with the NIT Outstanding Doctoral Res

12. I received my Master of Science degree in Electrical Engineering from the Massachusetts Institute of Technology in 1995, where my thesis research focused on coherent optical detection systems for long-haul telecommunications applications. This work gave me deep familiarity with coherent transceiver architectures, including the modulation and detection techniques that are central to the '193 Patent.

13. I received my Bachelor of Science degree in Physics from Stanford University in 1993, graduating summa cum laude with distinction. My undergraduate research involved the characterization of semiconductor laser diodes and their coupling to optical fibers, which introduced me to the principles of grating coupler design and polarization management that are relevant to the '015 Patent. B. Professional Experience

14. I have been a Professor of Electrical Engineering & Photonics at the Northfield Institute of Technology since 2002, and I was granted tenure in 2005. Prior to joining NIT, I held a postdoctoral research position at the Westmark Group (2000–2002), where I worked on silicon photonic integrated circuit design for optical interconnects. In total, I have more than twenty-five years of professional and research experie

15. During my career, I have published over 150 peer-reviewed journal articles and conference papers in leading venues including Nature Photonics, Optica, IEEE Journal of Lightwave Technology, IEEE Photonics Technology Letters, Optics Express, and the proceedings of the Optical Fiber Communication Conference (OFC), the European Conference on Optical Communication (ECOC), and the Conference on Lasers and Electro-Optic

16. I hold twelve (12) issued United States utility patents in the field of silicon photonics. These patents cover inventions relating to waveguide taper designs, integrated coherent receiver architectures, micro-thermal management structures for photonic circuits, and grating coupler geometries with enhanced polarization handling. A complete listing of my patents is included in my curriculum vitae (Appendix D).

17. Throughout my career, I have served as a technical consultant to multiple semiconductor and optical networking companies, including advising on photonic integrated circuit design, optical transceiver architecture, and silicon photonic fabrication process development. My consulting engagements have given me practical, hands-on experience with the commercial design and manufacture of the types of devices at issue i

18. I have previously been retained as an expert witness in patent infringement matters involving photonic integrated circuits and optical transceiver technologies. A complete listing of my prior testimony is provided in Appendix E. Specifically, within the past four years, I have testified as an expert at trial in Coriant Technologies GmbH v. Harborline Partners LLC, No. 3:20-cv-04517-WHO (N.D. Cal.) and provided de

19. As noted above, I am being compensated at the rate of $950 per hour for all time spent on this engagement. This rate is consistent with the rates I have charged in prior expert engagements in patent litigation. My compensation is in no way contingent upon the opinions I express, the outcome of this litigation, or the success of any party. I am being compensated for my time and expertise, regardless of the conclus

20. My full curriculum vitae, including a complete listing of my education, employment history, publications, patents, prior expert engagements, honors and awards, and professional affiliations, is attached to this report as Appendix D (Exhibit 1) and is incorporated herein by reference.

21. In forming the opinions expressed in this report, I have reviewed, analyzed, and relied upon the materials described below. A complete enumeration of all materials considered is set forth in Appendix C to this report. I reserve the right to rely on additional materials produced or made available after the date of this report. A. Patent Documents

22. I have reviewed the complete patents-in-suit, including the specifications, claims, drawings, and cover pages of the following United States utility patents: (a) U.S. Patent No. 10,234,847 (the "'847 Patent"), entitled "Multi-Channel Silicon Photonic Waveguide Multiplexer with Low Insertion Loss," filed September 14, 2016, and issued March 19, 2019. The original and current assignee of the '847 Patent is Optiwave

23. I have confirmed that all maintenance fees are current on all four asserted patents, and that each patent remains in force as of the date of this report. I understand from counsel that the chain of title for each patent has been verified and is not disputed. B. Prosecution Histories

24. I have reviewed the complete file histories (prosecution histories) of all four asserted patents as prosecuted by Cascade IP Advisors, LLC (Dr. Martin Chu, Lead Patent Prosecution Attorney, 1550 Crystal Drive, Suite 600, Arlington, VA 22202). My review of the prosecution histories included all office actions issued by the United States Patent and Trademark Office ("USPTO"), all applicant responses and amendments,

25. I have reviewed the following claim construction materials filed or exchanged in this action: (a) OWS's Opening Claim Construction Brief, filed November 15, 2024; (b) Lumicore's Responsive Claim Construction Brief, filed December 6, 2024; (c) OWS's Reply Claim Construction Brief, filed December 20, 2024; (d) Lumicore's Sur-Reply Claim Construction Brief, filed January 10, 2025; (e) Joint Claim Construction Statem

26. This infringement report is based on OWS's proposed claim constructions for all fourteen disputed terms. As noted in Section XI below, my opinions are subject to revision based on the claim construction ruling that will issue following the Markman hearing scheduled for March 14, 2025. D. Infringement Contentions

27. I have reviewed OWS's P.R. 3-1 Infringement Contentions, served on Lumicore on September 16, 2024, together with the accompanying Infringement Claim Charts for each asserted patent and each Accused Product. These materials identify, on a claim-by-claim and limitation-by-limitation basis, the specific structures, acts, and evidence supporting OWS's contention that each Accused Product infringes the asserted claims

28. I have reviewed extensive materials relating to the Accused Products, including the following: (a) Benchmark Semiconductor Analysis, LLC Teardown Reports. Benchmark Semiconductor Analysis, LLC ("Benchmark"), located at 2244 Mission College Boulevard, Santa Clara, CA 95054, performed independent physical teardowns of each of the three Accused Products. I have reviewed the following teardown reports: (i) LumiLink 4

29. I have reviewed the following deposition transcripts, including all exhibits thereto: (a) Deposition of Dr. Sandra Michaud, Chief Technology Officer, Lumicore Technologies, Inc., taken November 19, 2024. Dr. Michaud's testimony is significant to my analysis for several reasons. Among other things, Dr. Michaud admitted that Lumicore's design team reviewed OWS's published patent application No. 2018/0123456 (which

30. In addition to the materials described above, I have reviewed the following: (a) Lumicore's Invalidity Contentions, served October 14, 2024, including all twenty-three (23) prior art references cited by Lumicore. I have reviewed these references for context in understanding Lumicore's anticipated defenses, although I have not been asked to opine on validity in this report. (b) OWS's product documentation for its

IV. PERSON OF ORDINARY SKILL IN THE ART (POSITA) A. Definition

31. It is my opinion that a person of ordinary skill in the art ("POSITA") at the time of the filing dates of the asserted patents would have had the following qualifications: (a) A Master of Science (M.S.) or Doctor of Philosophy (Ph.D.) degree in electrical engineering, photonics, optical engineering, applied physics, or a closely related field; and (b) At least three (3) years of professional or research experienc

32. I note that, consistent with general principles recognized in the art, a higher level of education may substitute for some professional experience, and vice versa. For example, a person with a Ph.D. in integrated photonics and two years of relevant post-doctoral or industry experience would qualify as a POSITA, as would a person with an M.S. degree and five or more years of hands-on design experience in silicon p

33. The POSITA definition set forth above is consistent with the definition I provided in my Declaration in Support of OWS's Opening Claim Construction Brief, submitted on November 15, 2024. This definition reflects the level of sophistication of the art at the relevant time periods, as evidenced by the complexity and technical depth of the specifications of the four asserted patents, the nature and content of the pr

34. I understand that Lumicore's designated expert, Dr. Rajesh Sundaram of Pacific Western University, may propose a different POSITA definition in his expert report. I reserve the right to address Dr. Sundaram's proposed definition in my rebuttal report, should his definition differ materially from the one I have set forth here.

35. In order to provide the Court and jury with the necessary context for understanding the infringement analysis that follows, I will briefly describe the relevant technologies. The four asserted patents relate to specific innovations in the field of silicon photonics, and each addresses a distinct technical challenge within that field: waveguide multiplexing (the '847 Patent), coherent optical transceiver integrati

36. Silicon photonics is a technology platform for fabricating optical devices and circuits on silicon substrates using standard semiconductor fabrication processes that are compatible with complementary metal-oxide-semiconductor ("CMOS") manufacturing. The fundamental advantage of silicon photonics lies in its ability to leverage the enormous infrastructure and economies of scale of the silicon semiconductor industr

37. Silicon photonic technology has found its most significant commercial applications in data-center interconnects and telecommunications, where there is a relentless demand for higher bandwidth, lower power consumption, and smaller form factors. Modern data centers require enormous volumes of optical transceivers to connect servers, switches, and routers across short-reach, medium-reach, and long-reach links. Silic

38. Key components that can be fabricated on a silicon photonic platform include: • Optical waveguides: The fundamental building blocks that guide light on the chip, analogous to electrical wires in an electronic circuit. Silicon waveguides exploit the high refractive-index contrast between silicon (n ≈ 3.48 at 1550 nm) and silicon dioxide (n ≈ 1.44) to confine and route optical signals with sub-micron cross-sections

39. Wavelength-division multiplexing ("WDM") is a technique for combining multiple optical signals of different wavelengths onto a single waveguide or optical fiber, thereby multiplying the data-carrying capacity of the optical link. WDM is essential to modern optical communications because it allows a single fiber or waveguide to carry many independent data channels simultaneously, each at a different wavelength of

40. Several different approaches exist for implementing waveguide multiplexers on silicon photonic platforms. These include: • Arrayed Waveguide Gratings (AWGs): AWGs use an array of waveguides with precisely controlled path-length differences to create constructive interference at specific output positions for each wavelength. AWGs are widely used for high-channel-count multiplexing but can suffer from relatively hi

41. Key performance metrics for waveguide multiplexers include insertion loss (the optical power lost when signals pass through the multiplexer, measured in decibels), crosstalk (the degree to which a signal on one wavelength channel leaks into an adjacent channel), channel count (the number of wavelength channels the multiplexer can handle), and channel spacing (the spectral separation between adjacent channels, typ

42. The '847 Patent is entitled "Multi-Channel Silicon Photonic Waveguide Multiplexer with Low Insertion Loss" and addresses the challenge of achieving low insertion loss in a multi-channel waveguide multiplexer fabricated on a silicon photonic platform. The patent discloses novel waveguide geometry and coupling designs that achieve significantly lower insertion loss than prior art multiplexer architectures. C. Coher

43. Coherent optical transceivers represent a significant advancement over traditional direct-detect transceivers. In a direct-detect system, the receiver simply detects the intensity (power) of the incoming optical signal. In contrast, a coherent transceiver detects both the amplitude and phase of the optical signal by interfering the received signal with a local oscillator (a reference laser). This coherent detecti

44. In addition, coherent transceivers can exploit polarization-division multiplexing (PDM), which doubles the data rate by independently modulating data onto two orthogonal polarization states of the optical signal. When combined with advanced modulation formats, PDM-enabled coherent transceivers can achieve aggregate data rates of 400 Gbps, 800 Gbps, and beyond on a single wavelength channel.

45. The integration of coherent transceiver functionality onto a silicon photonic substrate offers significant advantages in terms of cost, size, power consumption, and manufacturability. Key components of an integrated coherent transceiver include: • Modulator: Encodes data onto the optical carrier using phase and amplitude modulation. For coherent transceivers, nested Mach-Zehnder modulators or IQ modulators are co

46. The '193 Patent is entitled "High-Bandwidth Coherent Optical Transceiver Integrated on Silicon Substrate" and addresses the challenge of integrating all of these coherent transceiver functions onto a single silicon photonic platform, achieving high bandwidth and performance through innovative integration architecture and coherent detection module design. D. Thermal Management of Photonic Integrated Circuits

47. Photonic integrated circuits ("PICs") generate significant heat during operation, particularly from integrated electronic components (such as driver amplifiers, TIAs, and DSP interfaces), on-chip or hybrid-integrated laser sources, and thermo-optic tuning elements. This heat generation is a critical problem because many photonic devices are highly sensitive to temperature variations. For example, ring resonator-b

48. Effective thermal management is therefore essential for maintaining the performance, reliability, and lifetime of photonic integrated circuits. Traditional approaches to thermal management in PICs have included thermoelectric coolers (TECs), heat spreaders, and conventional heat sinks attached to the top or bottom of the PIC package. However, these approaches often provide insufficient heat dissipation for the in

49. Micro-channel heat sinks represent an advanced approach to thermal management that provides exceptionally high heat-flux dissipation. In a micro-channel heat sink, coolant (which may be a liquid or a two-phase fluid) is routed through channels with very small hydraulic diameters—typically on the order of tens to hundreds of micrometers. The small hydraulic diameter creates a large surface-area-to-volume ratio, wh

50. The '562 Patent is entitled "Method for Thermal Management of Photonic Integrated Circuits Using Embedded Micro-Channel Heat Sinks" and discloses a method for managing the thermal load in PICs by embedding micro-channel heat sinks within or adjacent to the PIC substrate, with specific innovations in micro-channel geometry, integration with the PIC fabrication process, and thermal coupling architecture. E. Polariz

51. Grating couplers are structures used to couple light between optical fibers and on-chip waveguides in silicon photonic integrated circuits. The coupling is achieved by a periodic or quasi-periodic pattern of ridges or grooves etched into the waveguide surface, which diffracts light at a specific angle determined by the grating period and the wavelength of light. Grating couplers are favored over edge couplers in

52. A fundamental challenge with standard one-dimensional grating couplers is that they are inherently polarization-sensitive. The diffraction efficiency of a grating depends on the orientation of the electric field of the incoming light relative to the grating grooves. Light polarized parallel to the grating grooves (transverse electric, or "TE," mode) diffracts differently from light polarized perpendicular to the

53. Polarization-diverse grating couplers solve this problem by coupling both TE and TM polarization states with comparable efficiency. One common approach is to use a two-dimensional grating structure—a grating with periodicity in two orthogonal directions—that simultaneously diffracts both polarization states into separate on-chip waveguides. The two waveguides then carry the two polarization components independent

54. The '015 Patent is entitled "Polarization-Diverse Grating Coupler for Silicon Photonic Transceivers" and discloses an innovative grating coupler design that achieves polarization diversity through specific grating geometry, polarization-splitting architecture, and sub-wavelength features that enhance coupling efficiency for both TE and TM modes.

VI. THE ASSERTED PATENTS A. U.S. Patent No. 10,234,847 (the "'847 Patent")