Contract analysis

I. Executive Summary The purpose of this memorandum is to assess the viability of Optiwave Semiconductor Corp.'s ("OWS" or "Plaintiff") infringement theories for U.S. Patent No. 10,234,567 ("the '567 Patent") following the Markman Order issued on February 17, 2023, by the Honorable Edward J. Torvelis of the United States District Court for the Northern District of California. This analysis addresses all five asserted

II. Background A. The '567 Patent Overview U.S. Patent No. 10,234,567, entitled "Integrated Waveguide Coupler with Tapered Mode Converter for Silicon Photonics Platforms," was filed on March 14, 2017, and issued on March 19, 2019, after prosecution before the United States Patent and Trademark Office. The patent is assigned to Optiwave Semiconductor Corp., our client. The named inventors on the '567 Patent are: (1) D

1. LumosBridge™ 800G Optical Engine. The LumosBridge™ 800G is a co-packaged optics (CPO) engine designed for integration with high-bandwidth switch ASICs in hyperscale data center environments. The product was first shipped commercially in the first quarter of 2022. Based on publicly available pricing information and discovery responses, the unit price of the LumosBridge™ 800G ranges from approximately $1,200 to $1,8

2. LumosEdge™ 400ZR+ Pluggable Transceiver. The LumosEdge™ 400ZR+ is a QSFP-DD form factor pluggable optical transceiver designed for metro and data center interconnect (DCI) applications. The product has been in production and commercially available since the third quarter of 2021. Unit pricing for the LumosEdge™ 400ZR+ ranges from approximately $600 to $900 per unit. Based on Lumos's annual report on Form 10-K for

III. The Court's Claim Construction — "Adiabatically Coupled" A. Summary of the Parties' Positions The parties presented sharply divergent proposed constructions for the term "adiabatically coupled" as it appears in Claim 1 of the '567 Patent. The dispute centered on whether the term should be construed functionally — defining the coupling by the result it achieves — or structurally — defining the coupling by the phy

1. OWS's Proposed Construction OWS proposed that "adiabatically coupled" be construed to mean: "coupled such that optical mode transitions occur without significant power loss." OWS's construction was grounded in several arguments. First, OWS contended that the term should be given its plain and ordinary meaning to a person of ordinary skill in the art of integrated photonics. OWS argued that in the field, "adiabatic

2. Lumos's Proposed Construction Lumos proposed that "adiabatically coupled" be construed to mean: "coupled through a gradual, continuous taper that prevents excitation of higher-order modes throughout the entire transition region." Lumos's construction was grounded in both intrinsic and extrinsic evidence. Lumos argued, first, that the prosecution history compelled a structural interpretation. The "adiabatically cou

1. A gradual taper — the taper must vary smoothly and gradually in width, not abruptly or in discrete steps.

2. A continuous taper — the taper must be continuous, without segmentation, discontinuities, or discrete coupling sections. A taper composed of discrete segments separated by transition discontinuities does not satisfy this requirement.

3. Designed and configured to prevent higher-order mode excitation — the taper must be designed and configured such that higher-order optical modes are not excited during the mode transition. This is a design-intent requirement that reinforces the structural character of the limitation.

4. Over the entire transition length — the above properties must be maintained over the entire length of the taper transition, not merely at discrete points or in isolated sections. The critical consequence of this construction is that it imposes a structural limitation on the coupling mechanism, not merely a functional one. A coupler that achieves low-loss mode transfer through a mechanism other than a gradual, cont

IV. Claim-by-Claim Infringement Analysis Under the Court's Construction A. Claim 1 Claim 1 is the independent claim from which all other asserted claims depend. The dispositive limitation for purposes of the infringement analysis is "adiabatically coupled," as construed by the Court.

1. The Dispositive Limitation: "Adiabatically Coupled" Lumos's Accused Design. Based on the discovery produced to date — including Lumos's technical design documents (LMPH-000147523 through LMPH-000147891), process design kit specifications, and internal engineering presentations — as well as publicly available technical documentation (including Lumos's published papers, conference presentations, and product datashee

V. Doctrine of Equivalents Analysis Even where literal infringement cannot be established, a patentee may sometimes rely on the doctrine of equivalents ("DOE") to capture accused products that perform substantially the same function, in substantially the same way, to achieve substantially the same result as the claimed invention. See Warner-Jenkinson Co. v. Harborline Enterprises Davis Chem. Co., 520 U.S. 17 (1997).

1. The Narrowing Amendment The "adiabatically coupled" limitation was not present in the original claims of the '567 Patent application as filed on March 14, 2017. It was added by amendment during prosecution in response to the United States Patent and Trademark Office's second office action, which maintained a rejection of the claims under 35 U.S.C. § 102(a)(1) as anticipated by the Tanaka prior art — U.S. Patent No

2. Application of *Festo* Under the Supreme Court's decision in Festo Corp. v. Fenmore & Co., 535 U.S. 722 (2002), when a patent holder narrows a claim by amendment during prosecution for a reason related to patentability, there is a presumption that the amendment surrendered the territory between the original claim and the amended claim. This presumption of prosecution history estoppel prevents the patent holder fro

3. Analysis of the *Festo* Rebuttal Exceptions Under Festo, the presumption of prosecution history estoppel can be rebutted in three narrow circumstances. We analyze each in turn. Exception 1: Unforeseeability. The patentee may rebut the presumption by showing that the alleged equivalent was unforeseeable at the time of the amendment. Here, segmented taper couplers were well-known and well-documented in the art at th

4. Conclusion on Estoppel Because all three Festo rebuttal exceptions fail, the presumption of prosecution history estoppel is unrebutted. OWS is estopped from asserting the doctrine of equivalents with respect to the "adiabatically coupled" limitation against Lumos's segmented taper coupler design. This forecloses any DOE-based infringement theory for all five asserted claims. B. Independent DOE Analysis (Even Absen

VI. Impact Assessment: Comparison to Pre-Markman Position The Court's Markman Order has fundamentally altered the litigation posture with respect to the '567 Patent. A comparison of the pre-Markman and post-Markman positions illustrates the magnitude of this shift. Pre-Markman Position. Under OWS's proposed functional construction of "adiabatically coupled," the infringement case against the '567 Patent was assessed

VII. Consideration of Alternative Theories A. Indirect Infringement We have considered whether OWS's infringement theories for the '567 Patent could be reformulated as claims of indirect infringement — either induced infringement under 35 U.S.C. § 271(b) or contributory infringement under 35 U.S.C. § 271(c). The answer is no. Both theories of indirect infringement require, as an essential predicate, the existence of

VIII. Conclusions and Recommendations Based on the foregoing analysis, we reach the following conclusions and recommendations: Conclusion. Infringement of asserted Claims 1, 4, 7, 12, and 15 of U.S. Patent No. 10,234,567 is untenable under the Court's Markman Order construction of "adiabatically coupled." Lumos's segmented (non-continuous) taper coupler architecture, as implemented in both the LumosBridge™ 800G Optic