Contract analysis

I. EXECUTIVE SUMMARY A. Overview of the Asserted Patents This memorandum analyzes the prosecution histories of the four United States utility patents asserted by Optiwave Semiconductor Corp. ("OWS" or "Optiwave") in its complaint against Lumicore Technologies, Inc., filed on May 1, 2024, in the United States District Court for the Eastern District of Texas. The four asserted patents are:

1. U.S. Patent No. 9,678,562 ("the '562 Patent") — "Method for Thermal Management of Photonic Integrated Circuits Using Embedded Micro-Channel Heat Sinks," issued June 13, 2017;

2. U.S. Patent No. 10,234,847 ("the '847 Patent") — "Multi-Channel Silicon Photonic Waveguide Multiplexer with Low Insertion Loss," issued March 19, 2019;

3. U.S. Patent No. 10,891,193 ("the '193 Patent") — "High-Bandwidth Coherent Optical Transceiver Integrated on Silicon Substrate," issued January 12, 2021; and

4. U.S. Patent No. 11,402,015 ("the '015 Patent") — "Polarization-Diverse Grating Coupler for Silicon Photonic Transceivers," issued August 2, 2022. All four patents are United States utility patents currently in force. Maintenance fees are current on all four patents, and no inter partes review ("IPR") petitions have been filed to date against any of the asserted patents. B. Family Relationships and Shared Provision

1. Prosecution History Estoppel ("PHE") — Claims 3 and 7 of the '193 Patent and Claim 12 of the '015 Patent: Narrowing amendments made during prosecution to overcome prior-art rejections trigger the Festo presumption of surrender for doctrine-of-equivalents ("DOE") contentions. Calderwood & Harkness's position is that the tangential-relation exception to the Festo presumption applies in both instances, but this is a

2. Inequitable Conduct Allegation — '193 Patent: Lumicore filed a counterclaim on June 17, 2024, alleging inequitable conduct and unenforceability of the '193 Patent based on the alleged failure of named inventor Dr. Jian-Wei Huang to disclose a material prior publication to the USPTO during prosecution. Calderwood & Harkness assesses this counterclaim as ultimately unsuccessful under the Brightmoor & Co. standard, b

3. Priority Date Vulnerability — '015 Patent: If the provisional application (No. 62/499,117) does not adequately support the polarization-diverse grating coupler claims of the '015 Patent, the effective filing date for those claims shifts from April 7, 2017 to August 30, 2019, potentially opening the door to Lumicore's prior-conception defense and additional intervening prior art. This issue is discussed in detail i

II. U.S. PATENT NO. 9,678,562 (THE '562 PATENT) A. Bibliographic Data • Title: "Method for Thermal Management of Photonic Integrated Circuits Using Embedded Micro-Channel Heat Sinks" • Filing Date: November 22, 2014 • Issue Date: June 13, 2017 • Application No.: 14/550,812 • Original Assignee: Solara Optics, Inc. • Current Assignee: Optiwave Semiconductor Corp. (acquired via Asset Purchase Agreement dated June 15, 20

1. First Office Action (Non-Final Rejection) — March 10, 2015 The USPTO issued a non-final office action on March 10, 2015, rejecting Claims 1–7, 15, and 20–24 under 35 U.S.C. § 102(a)(1) as anticipated by Li Wei, "Thermal Solutions for Photonic Integrated Circuits," presented at the Optical Fiber Communications Conference (OFC 2013), March 2013 ("Li Wei"). Claims 8–14 were rejected under 35 U.S.C. § 103 as obvious o

2. Applicant's Response to First Office Action — July 8, 2015 Dr. Martin Chu of Cascade IP Advisors filed a response on July 8, 2015, amending claims and presenting arguments to overcome the rejections. Amendments to Claims: Independent Claim 1 was amended to add a structural limitation specifying the relationship between the micro-channels and the active photonic components: "1. A method for thermal management of a

3. Second Office Action (Final Rejection) — November 12, 2015 The examiner issued a final rejection on November 12, 2015, maintaining the § 103 rejection of Claims 8–14 over Li Wei in combination with Bergmann. The examiner accepted the applicant's amendments to Claims 1–7 and 15–24, withdrawing the § 102 rejection of those claims and the § 112(b) rejection of Claims 15–19. However, the examiner maintained that Claim

4. Applicant's Response — Request for Continued Examination (RCE) — February 16, 2016 Dr. Chu filed a Request for Continued Examination ("RCE") on February 16, 2016, accompanied by further amendments to Claims 8–14 and additional arguments. Independent Claim 8 was amended to add a limitation requiring that the manifold inlet and outlet be "monolithically integrated into the PIC substrate," which Dr. Chu argued was no

5. Examiner Interview — April 22, 2016 An examiner interview was conducted by telephone on April 22, 2016. Participants included Dr. Martin Chu (Cascade IP Advisors) and Primary Examiner David R. Nguyen (Art Unit 2882). The interview summary form, filed April 25, 2016, indicates that the examiner agreed that the monolithic integration limitation in amended Claim 8 distinguished the claimed invention from the Li Wei /

6. Notice of Allowance — June 8, 2016 The examiner issued a Notice of Allowance on June 8, 2016, allowing Claims 1–24 as amended. The examiner's statement of reasons for allowance stated: "The prior art of record, including Li Wei and Bergmann, does not teach or suggest the combination of forming micro-channels with a hydraulic diameter of less than 1 mm directly beneath an active waveguide region of a photonic integ

1. Original Assignment (November 22, 2014): The application was filed by Solara Optics, Inc. All three named inventors (Dr. Elena Sorokina, Dr. Marcus T. Brenner, and Yuki Tanaka) executed assignments to Solara Optics, Inc. as of the filing date. The assignment was recorded at the USPTO on December 3, 2014 (Reel/Frame: 034,321/0045).

2. Asset Purchase Agreement (June 15, 2018): Solara Optics, Inc. transferred the '562 Patent to Optiwave Semiconductor Corp. pursuant to an Asset Purchase Agreement dated June 15, 2018, for a total consideration of $34.5 million covering twelve patents, including the '562 Patent. The assignment was recorded at the USPTO on July 2, 2018 (Reel/Frame: 046,274/0112).

3. Chain of Title Confirmation: The chain of title from the named inventors through Solara Optics, Inc. to OWS has been reviewed and confirmed as clean. There are no gaps, competing claims, or unresolved encumbrances. Solara Optics, Inc. was dissolved in 2020; however, the dissolution occurred after the assignment to OWS and does not affect OWS's ownership rights. Gregory Falk, the former Vice President of Engineerin

1. Applicant's Remarks (July 8, 2015): Dr. Chu's remarks in the response to the first office action defined micro-channels as having a hydraulic diameter of "less than 1 mm, consistent with the commonly understood meaning of 'micro-channel' in the thermal management art." This language directly supports OWS's proposed upper bound of 1 mm and does not limit the term to the narrower 10–200 µm range proposed by Lumicore

2. Examiner's Oral Statement (April 22, 2016): The examiner stated in the interview summary that "micro-channel heat sink" is "understood to refer to a heat-dissipating structure with channels having a hydraulic diameter of less than 1 mm, as defined in the specification." This examiner statement corroborates OWS's construction.

3. No Closed-Loop Limitation: At no point during prosecution did the applicant or the examiner limit "micro-channel heat sink" to a "closed-loop liquid-cooling system." The specification describes both open-loop and closed-loop embodiments, and neither the applicant's amendments nor the examiner's reasons for allowance imposed such a limitation. Lumicore's proposed construction impermissibly imports a limitation from

1. Bergmann (U.S. Patent No. 8,412,007) Lumicore asserts Bergmann as an obviousness reference under § 103 against the '562 Patent. Bergmann was before the examiner during prosecution and was cited in the first office action (March 10, 2015) as part of a § 103 combination with Li Wei. The applicant distinguished Bergmann during prosecution by amending the claims to require monolithic integration of manifold structures

2. Li Wei (OFC 2013 Conference Paper) Lumicore asserts Li Wei as an anticipation reference under § 102 against the '562 Patent. Li Wei was before the examiner and was the primary basis for the § 102 rejection in the first office action. The applicant overcame the § 102 rejection by amending the claims to add the "directly beneath an active waveguide region" limitation and by arguing that Li Wei described channels adj

3. Priority Date Analysis The '562 Patent's effective filing date is November 22, 2014. Both Bergmann (issued April 2, 2013) and Li Wei (published March 2013) predate this filing date and qualify as prior art under § 102(a)(1). No swearing-behind evidence was submitted during prosecution, and none would be applicable under the current first-inventor-to-file regime (the '562 Patent was filed after the AIA effective da

4. Secondary Considerations Secondary considerations of non-obviousness applicable to the '562 Patent are discussed in the separate Secondary Considerations Memorandum (to be completed December 2024). OWS intends to rely on evidence of commercial success (the technology is embodied in OWS's OW-ThermalMax product line, which has generated over $120 million in revenue since launch), long-felt but unresolved need for ef

1. Prosecution History Estoppel The amendments made during prosecution of the '562 Patent narrowed the claims in several respects: the addition of the "hydraulic diameter of less than 1 mm" limitation, the "directly beneath an active waveguide region" limitation, and the "monolithically integrated" manifold limitation. However, because DOE is not asserted for any of the '562 Patent claims in this litigation, the pros

2. Claim Scope Narrowing Lumicore may argue that the applicant's prosecution arguments — particularly the statement distinguishing Li Wei based on the 2 mm channel dimension — create a prosecution disclaimer limiting "micro-channel" to channels significantly smaller than 1 mm. However, the applicant's statement was directed to distinguishing a specific reference, not to defining the full scope of the term, and the cl

3. Inequitable Conduct We have not identified any material references that were known to the applicants or prosecution counsel but were not disclosed to the USPTO during prosecution of the '562 Patent. All prior-art references identified in the specification's background section and in the inventors' knowledge at the time of filing appear to have been disclosed via IDS or were independently cited by the examiner. The

III. U.S. PATENT NO. 10,234,847 (THE '847 PATENT) A. Bibliographic Data • Title: "Multi-Channel Silicon Photonic Waveguide Multiplexer with Low Insertion Loss" • Filing Date: September 14, 2016 • Issue Date: March 19, 2019 • Application No.: 15/265,490 • Original Assignee: Optiwave Semiconductor Corp. • Current Assignee: Optiwave Semiconductor Corp. • Named Inventors: Dr. Jian-Wei Huang; Dr. Elena Sorokina; Dr. Marcu

1. First Office Action (Non-Final Rejection) — April 18, 2017 The USPTO issued a non-final office action on April 18, 2017, rejecting Claims 1–8 under 35 U.S.C. § 102(a)(1) as anticipated by Takahashi et al., "Dense WDM Silicon Photonic Multiplexer," IEEE Photonics Technology Letters, Vol. 26, No. 5, pp. 485–488, March 2014 ("Takahashi"). Claims 9–15 were rejected under 35 U.S.C. § 103 as obvious over Takahashi in vi

2. Applicant's Response — August 22, 2017 Dr. Martin Chu filed a response on August 22, 2017, amending claims and presenting arguments to overcome the rejections. Amendments to Claims: Independent Claim 1 was amended to add a structural limitation distinguishing the claimed waveguide multiplexer from the arrayed waveguide grating disclosed in Takahashi: "1. A silicon photonic waveguide multiplexer, comprising: a plur

3. Second Office Action (Non-Final) — January 9, 2018 The examiner issued a second non-final office action on January 9, 2018, withdrawing the § 102 rejection of Claims 1–8 over Takahashi and the § 103 rejection of Claims 9–15 over Takahashi/Simonsen. However, the examiner raised a new § 103 rejection of Claims 1–8 over a newly cited reference: Park et al., "Cascaded Mach-Zehnder Lattice Filter for Silicon Photonic W

4. Applicant's Response — May 7, 2018 Dr. Chu filed a response on May 7, 2018, arguing that Park did not disclose the claimed insertion-loss performance and that the examiner had not established a prima facie case of obviousness. Dr. Chu submitted supplemental experimental data (under a Rule 132 Declaration from Dr. Jian-Wei Huang) demonstrating that the specific MZI cascade design described in the '847 Patent specif

5. Examiner Interview — June 15, 2018 An examiner interview was conducted by telephone on June 15, 2018. Participants included Dr. Martin Chu (Cascade IP Advisors) and Primary Examiner Sarah K. Yoo (Art Unit 2872). The interview summary form, filed June 18, 2018, indicates that the examiner found Dr. Huang's comparative data persuasive and agreed that the claimed insertion-loss performance was not taught or rendered

6. Notice of Allowance — August 14, 2018 The examiner issued a Notice of Allowance on August 14, 2018, allowing Claims 1–22 as amended. The examiner's statement of reasons for allowance stated: "The prior art of record does not teach or suggest a silicon photonic waveguide multiplexer with a waveguide combining region comprising a cascade of Mach-Zehnder interferometer stages that achieves an insertion loss of less t

1. Takahashi et al. (March 2014) Lumicore asserts Takahashi as an anticipation reference under § 102 against the '847 Patent. Takahashi was before the examiner during prosecution and was the primary basis for the § 102 rejection of Claims 1–8 in the first office action. The examiner withdrew the § 102 rejection after the applicant amended the claims to recite the MZI cascade architecture. Thus, Takahashi was consider

2. Simonsen (PCT/EP2015/071234, September 17, 2015) Lumicore asserts Simonsen as an obviousness reference under § 103, presumably in combination with other references. Simonsen was before the examiner during prosecution and was cited in the § 103 rejection of Claims 9–15. The examiner withdrew the rejection after the applicant's amendment. Critically, Simonsen's publication date (September 17, 2015) is after the '562

3. Other References Lumicore's invalidity contentions cite a total of six prior-art references against the '847 Patent. In addition to Takahashi and Simonsen, Lumicore cites Park et al. (November 2014), U.S. Patent Application Publication No. 2015/0331181 to Chen (November 2015), and two additional references. Park was before the examiner (cited in the second office action), and the examiner's reasons for allowance s

1. Waveguide Multiplexer Prosecution Disclaimer Risk The principal risk for the '847 Patent is that Lumicore successfully argues that the prosecution history limits "waveguide multiplexer" and the combining-region limitation to MZI-cascade architectures only. If the accused products employ a different multiplexer architecture (e.g., an echelle grating or a micro-ring resonator array), Lumicore could argue non-infring

2. Prosecution History Estoppel DOE is not asserted for any of the '847 Patent claims. The prosecution history estoppel risk is therefore limited to claim construction breadth, not DOE scope. Risk assessment: LOW.

3. Cross-Patent Consistency The '847 Patent shares named inventor Dr. Elena Sorokina with the '562 Patent, and the prosecution arguments in the '847 Patent regarding thermal management (in Claims 16–22) must be consistent with the prosecution arguments in the '562 Patent. No inconsistencies have been identified. Risk assessment: LOW.

IV. U.S. PATENT NO. 10,891,193 (THE '193 PATENT) A. Bibliographic Data • Title: "High-Bandwidth Coherent Optical Transceiver Integrated on Silicon Substrate" • Filing Date: April 7, 2017 • Issue Date: January 12, 2021 • Application No.: 15/481,692 • Original Assignee: Optiwave Semiconductor Corp. • Current Assignee: Optiwave Semiconductor Corp. • Named Inventors: Dr. Jian-Wei Huang; Dr. Nikolai Petrov; Dr. Amara Osei