Silicon photonics device and communication system therefor

1. A silicon photonics device comprising:

a substrate member;

an interface for receiving an input, the input including a transverse electric (TE) component and a transverse magnetic (TM) component;

a polarization beam splitter (PBS) overlying the substrate member, the PBS being configured to split the input into a TE output and a TM output, the TE output comprising the TE component, the TM output comprising the TM component;

a TE optimized demultiplexer (demux) overlying the substrate member, the TE optimized demux having a TE demux input coupled to the TE output, the TE optimized demux having a plurality of TE demux outputs, the TE optimized demux comprising a 300 nm×300 nm waveguide structure;

a TM optimized demux overlying the substrate member, the TM optimized demux having a TM demux input coupled to the TM output, the TM optimized demux having a plurality of TM demux outputs;

a plurality of paths including a first pair of paths and a second pair of paths;

a plurality of polarization beam combiners (PBC) including a first PBC and a second PBC, the first PBC being coupled to a first TE demux output and a first TM demux output via the first pair of paths, the first pair of paths being characterized by a first symmetrical length, the first PBC being configured to provide a first TE+TM output; and

a plurality of photodiode (PD) structures overlying the substrate, the plurality of PD structures including a first PD and a second PD, the first PD being coupled to the first PBC output.

2. The device of claim 1 wherein the second PBC is coupled to a second TE demux output and a second TM demux via the second pair of paths, the second pair of paths being characterized by a second symmetrical length.

3. The device of claim 2 wherein the second PD is coupled to the second PBC output.

4. The device of claim 1 wherein the TM optimized demux comprises an array waveguide gratings (AWG) structure.

5. The device of claim 1 wherein the PBS comprises a directional coupler.

6. The device of claim 1 wherein the PBC comprises a multimode interference coupler.

7. The device of claim 1 further comprising a silicon-on-insulator (SOI) layer overlaying the substrate member.

8. The device of claim 7 wherein the SOI layer is characterized by a top silicon thickness of 300 nm.

9. The device of claim 7 wherein the waveguide structure is configured from a portion of the substrate member.

10. The device of claim 7 wherein the waveguide structure comprises an index compensator material.

11. The device of claim 10 wherein the index compensator material comprises silicon based cladding material.

12. A silicon photonics device comprising:

a substrate member;

a polarization beam splitter (PBS) overlying the substrate member, the PBS being configured to split an input into a TE output and a TM output, the input comprising a transverse electric (TE) component and a transverse magnetic (TM) component, the TE output comprising TE component signals, the TM output comprising TM component signals;

a TE optimized demultiplexer (demux) overlying the substrate member, the TE optimized demux having a TE demux input coupled to the TE output, the TE optimized demux having a plurality of TE demux outputs, the TE optimized demux comprising an Echelle gratings structure characterized by a 300 nm top silicon thickness;

a TM optimized demux overlying the substrate member, the TM optimized demux having a TM demux input coupled to the TM output, the TM optimized demux having a plurality of TM demux outputs;

a plurality of paths including a first pair of paths and a second pair of paths;

a plurality of polarization beam combiners (PBC) including a first PBC and a second PBC, the first PBC being coupled to a first TE demux output and a first TM demux output via the first pair of paths, the first pair of paths being characterized by a first symmetrical length, the first PBC being configured to provide a first TE+TM output; and

a plurality of photodiode (PD) structures overlying the substrate, the plurality of PD structures including a first PD and a second PD, the first PD being coupled to the first PBC output.

13. The device of claim 12 wherein the Echelle grating structure comprises an index compensator material configured to provide the Echelle grating structure with at least two material index ratings.

14. The device of claim 13 wherein the index compensator material comprises SiO 2 , Si 3 N 4 , SiO x N y , and/or SiN x as a cladding material.

15. The device of claim 12 wherein the first PD comprises a first side, the first TE+TM output being coupled to the first side.

16. The device of claim 12 wherein the TE output and the TM output are characterized by different grating orders.

17. The device of claim 12 wherein the PBC is configured to align the first TE demux output and the first TM demux output using material birefringence characteristics.

18. The device of claim 12 wherein the PCB comprises a directional coupler, dimensions of the directional coupler being optimized based at least on birefringence characteristics.

19. The device of claim 12 wherein the TE output and the TM output are characterized by different indices.

20. A system comprising:

a polarization independent multiplexer/demultiplexer device comprising a waveguide characterized by a repeating feature of an Echelle grating, the Echelle grating including a SiO 2 region and a Si 3 N 4 region, a TE light input a TM light input being focused to the waveguide, wherein the TE light and the TM light are characterized by different grating orders; and

an interface coupled to the polarization independent multiplexer/demultiplexer device.