Contract analysis

1. A polarization-diverse grating coupler for a silicon photonic transceiver, comprising: a silicon-on-insulator substrate having a silicon device layer and a buried oxide layer; a two-dimensional grating structure formed in the silicon device layer, the grating structure comprising a periodic array of sub-wavelength features arranged in two orthogonal directions; wherein the two-dimensional grating structure is conf

2. The grating coupler of claim 1, wherein the sub-wavelength features have a period in each orthogonal direction of between 550 nm and 650 nm.

3. The grating coupler of claim 1, wherein the etch depth of the sub-wavelength features is between 50 nm and 180 nm.

4. The grating coupler of claim 1, further comprising a polarization rotator disposed in one of the first and second waveguides to convert the TM mode to a TE mode.

5. A silicon photonic transceiver module comprising: an optical input port configured to receive an optical signal from an optical fiber; a polarization-diverse grating coupler formed on a silicon-on-insulator substrate, the grating coupler comprising a two-dimensional sub-wavelength grating that splits the optical signal into a TE-polarized component directed to a first on-chip waveguide and a TM-polarized component

6. The transceiver module of claim 5, further comprising a waveguide multiplexer coupled to the coherent detection module for wavelength-division multiplexing of multiple optical channels.

7. The transceiver module of claim 5, wherein the grating coupler and the coherent detection module are monolithically integrated on a single silicon die.

8. A method of coupling light into a silicon photonic transceiver, comprising: directing an optical signal from an optical fiber onto a two-dimensional sub-wavelength grating formed in a silicon device layer of a silicon-on-insulator substrate; diffracting, by the two-dimensional sub-wavelength grating, a transverse-electric (TE) polarization component of the optical signal into a first silicon waveguide; diffracting

9. The method of claim 8, further comprising rotating the polarization of the TM component to a TE mode before processing.

10. The method of claim 8, wherein the diffracting steps achieve a coupling efficiency of at least −2 dB for each polarization component.

11. The method of claim 8, wherein the two-dimensional sub-wavelength grating comprises features having a period of between 550 nm and 650 nm in each of two orthogonal directions.

12. A polarization-diverse grating coupler, comprising: a two-dimensional sub-wavelength grating formed on a silicon photonic substrate, the grating comprising an array of etched features arranged in a two-dimensional periodic pattern with sub-wavelength periodicity in at least two directions; a first output waveguide coupled to the grating and configured to receive a first polarization state of an input optical sign

13. The grating coupler of claim 12, wherein the etched features comprise circular holes or pillars.

14. The grating coupler of claim 12, further comprising an apodization region wherein the dimensions of the etched features vary gradually from a center of the grating to a periphery.

15. The grating coupler of claim 12, further comprising a reflective layer disposed beneath the silicon photonic substrate to enhance upward coupling efficiency.

16. An integrated optical transceiver for data-center interconnect, comprising: a photonic integrated circuit formed on a silicon-on-insulator substrate; at least one polarization-diverse grating coupler integrated on the photonic integrated circuit, each grating coupler comprising a two-dimensional sub-wavelength grating configured to couple both transverse-electric and transverse-magnetic polarization states of an

17. The integrated optical transceiver of claim 16, wherein the aggregate data rate is at least 800 Gbps.

18. The integrated optical transceiver of claim 16, further comprising a thermal management structure for dissipating heat generated by the photonic integrated circuit.

19. The integrated optical transceiver of claim 16, wherein each polarization-diverse grating coupler achieves a polarization-dependent loss of less than 0.5 dB.

20. The integrated optical transceiver of claim 16, wherein the two-dimensional sub-wavelength grating of each grating coupler has a footprint of less than 20 µm × 20 µm. Filed as Exhibit D to the Complaint in Optiwave Semiconductor Corp. v. Lumicore Technologies, Inc., Case No. 2:24-cv-00319-JRG (E.D. Tex.), filed April 22, 2024. Counsel for Plaintiff: Alan Ngo, Marcus Delgado, Wendy Schultz, Omar Siddiqui Calderwoo