Contract analysis

I. Executive Summary The purpose of this memorandum is to assess whether Lumos Photonics, Inc. ("Lumos" or "LPI") infringes the asserted Claims 1, 4, 7, 12, and 15 of U.S. Patent No. 10,234,567 ("the '567 Patent") through its LumosBridge™ 800G Optical Engine and LumosEdge™ 400ZR+ Pluggable Transceiver products. This analysis has been prepared at the direction of Alan Ngo in anticipation of the potential filing of a p

II. Background A. The '567 Patent The patent at issue in this analysis is U.S. Patent No. 10,234,567, titled "Integrated Waveguide Coupler with Tapered Mode Converter for Silicon Photonics Platforms" (hereinafter, "the '567 Patent"). The relevant bibliographic data for the '567 Patent is as follows: The '567 Patent is directed to the field of silicon photonics, and more specifically to integrated optical coupler arch

1. LumosBridge™ 800G Optical Engine. The LumosBridge™ 800G is a co-packaged optics ("CPO") engine designed for integration with hyperscale data center network switches. Co-packaged optics represents an emerging architecture in which optical transceivers are integrated directly onto the switch package rather than being deployed as separate pluggable modules. The LumosBridge™ 800G incorporates a silicon photonic integr

2. LumosEdge™ 400ZR+ Pluggable Transceiver. The LumosEdge™ 400ZR+ is a pluggable optical transceiver module in the QSFP-DD (Quad Small Form Factor Pluggable – Double Density) form factor, designed for metro and data center interconnect ("DCI") applications. The LumosEdge™ 400ZR+ implements the OIF (Optical Internetworking Forum) 400ZR+ specification and incorporates a silicon photonic integrated circuit with coherent

III. Claim Language — Asserted Claims This section sets forth the full text of each of the five asserted claims of the '567 Patent. Each claim is presented verbatim as it appears in the issued patent, with individual limitations identified and numbered for purposes of the element-by-element infringement analysis in Section V below. A. Independent Claim 1 Claim 1 of the '567 Patent recites:

1. An integrated optical coupler comprising: a tapered silicon waveguide having a tip width of less than 200 nanometers, the tapered silicon waveguide being disposed on a substrate and having a longitudinal axis extending from a first end to a second end, the tip width being measured at the first end; a silicon nitride waveguide layer disposed adjacent to the tapered silicon waveguide and vertically separated therefr

4. The integrated optical coupler of claim 1, wherein the tapered silicon waveguide has a taper length of between 100 micrometers and 500 micrometers, and wherein the tapered silicon waveguide has a cross-sectional height of between 150 nanometers and 340 nanometers along the longitudinal axis. Claim 4 depends from Claim 1 and adds the following additional limitations: • [4a] — "the tapered silicon waveguide has a ta

7. The integrated optical coupler of claim 1, wherein the silicon nitride waveguide layer has a width of between 2 micrometers and 12 micrometers at an input facet and is configured such that the coupling efficiency between the silicon nitride waveguide layer and the tapered silicon waveguide exceeds 90% over a wavelength range of 1260 nm to 1360 nm. Claim 7 depends from Claim 1 and adds the following additional limi

12. An optical transceiver system comprising: a silicon photonic integrated circuit disposed on a silicon-on-insulator substrate, the silicon photonic integrated circuit comprising: an integrated waveguide coupler including a tapered silicon waveguide having a tip width of less than 200 nanometers adiabatically coupled to a silicon nitride waveguide layer through evanescent field interaction, the integrated waveguide

15. The optical transceiver system of claim 12, wherein the silicon nitride waveguide layer has a refractive index of between 1.9 and 2.1 at a wavelength of 1310 nm, and wherein the cladding layer separating the tapered silicon waveguide from the silicon nitride waveguide layer comprises silicon dioxide having a thickness of between 100 nanometers and 300 nanometers. Claim 15 depends from Claim 12 and adds the follow

IV. Prosecution History Summary A thorough review of the prosecution history of the '567 Patent is essential to the infringement analysis because (1) the prosecution history directly informs the construction of the critical "adiabatically coupled" limitation, and (2) the amendments and arguments made during prosecution give rise to potential prosecution history estoppel that may foreclose or limit application of the

V. Literal Infringement Analysis — Element-by-Element This section presents an element-by-element analysis of each asserted claim against the two accused Lumos products. Under well-established patent law, literal infringement requires that each and every limitation of a claim be met by the accused product. Pemberton Partners LLC v. F. Hoffmann-La Roche Ltd., 580 F.3d 1340, 1374 (Fed. Cir. 2009). If even one limitatio

VI. Doctrine of Equivalents Analysis A. Applicability If the Court construes "adiabatically coupled" narrowly to require a gradual, continuous taper that prevents excitation of higher-order modes throughout the entire transition region — thereby excluding Lumos's segmented taper design from the literal scope of the claims — OWS may seek to establish infringement under the doctrine of equivalents as an alternative the