Polarization splitters
Various embodiments relate to polarization splitters. A polarization splitter may include a silicon nitride (SiN) waveguide core configured to receive an input light signal having a first polarization mode and a second polarization mode. The polarization splitter may further include a silicon (Si) slot waveguide core disposed proximate the SiN waveguide core. The Si slot waveguide core may include a tapered portion at a first end configured to couple the first polarization mode to the Si slot waveguide.
1. A polarization splitter, comprising:
a silicon nitride (SiN) waveguide core configured to receive an input light signal including a first polarization mode and a second polarization mode; and
a silicon (Si) slot waveguide core disposed proximate the SiN waveguide core and including a tapered portion at a first end and configured to couple the first polarization mode to the Si slot waveguide core.
2. The polarization splitter of claim 1 , wherein the SiN waveguide core includes a coupling region aligned with the tapered portion of the Si slot waveguide core in at least two orthogonal directions.
3. The polarization splitter of claim 1 , further comprising a second SiN waveguide core spaced from the SiN waveguide core.
4. The polarization splitter of claim 3 , wherein the Si slot waveguide core further includes a second tapered portion at a second end, opposite the first end and configured to couple the first polarization mode to the second SiN waveguide core.
5. The polarization splitter of claim 4 , further comprising a polarization rotator disposed between an input port and an output port of the SiN waveguide core.
6. The polarization splitter of claim 1 , wherein the first polarization mode comprises a transverse electric (TE) polarization mode and the second polarization mode comprises a transverse magnetic (TM) polarization mode.
7. The polarization splitter of claim 1 , wherein the SiN waveguide core is formed in a layer of a Si photonic integrated circuit (PIC) and the Si slot waveguide core is formed in another layer of the Si PIC.
8. The polarization splitter of claim 1 , wherein the tapered portion has a length of about 300 μm.
9. A system that includes a polarization splitter (PS), the PS comprising:
a silicon nitride (SiN) channel waveguide configured to: receive an input light signal including a first polarization mode and a second polarization mode; and output a beam including the second polarization mode; and
a silicon (Si) slot waveguide disposed beneath the SiN channel waveguide and including a tapered portion at a first end and configured to couple the first polarization mode to the Si slot waveguide, the Si slot waveguide configured to output a beam including the first polarization mode.
10. The system of claim 9 , wherein the SiN channel waveguide includes a coupling region aligned with the tapered portion of the Si slot waveguide in at least two orthogonal directions.
11. The system of claim 9 , wherein the tapered portion of the Si slot waveguide has a width of about 320 nm at the first end and a width of about 400 nm at a second, opposite end of the tapered portion.
12. The system of claim 9 , wherein the SiN channel waveguide has a width of about 420 nm.
13. The system of claim 9 , wherein the tapered portion has a length of about 300 μm.
14. The system of claim 9 , further comprising a polarization rotator disposed between an input port and an output port of the SiN channel waveguide.
15. The system of claim 9 , wherein the first polarization mode comprises a transverse electric (TE) polarization mode and the second polarization mode comprises a transverse magnetic (TM) polarization mode.
16. The system of claim 9 , wherein the SiN channel waveguide is formed in a layer of a Si photonic integrated circuit (PIC) and the Si slot waveguide is formed in another layer of the Si PIC.
17. A polarization splitter, comprising:
a silicon nitride (SiN) waveguide core including a coupling region and configured to receive an input light signal including a first polarization mode and a second polarization mode; and
a silicon (Si) slot waveguide core disposed proximate the SiN waveguide core and including slot-to-channel converter, the Si waveguide core configured to couple to the first polarization mode.
18. The polarization splitter of claim 17 , wherein the Si slot waveguide core includes a tapered portion aligned with the coupling region of the SiN waveguide core in at least two orthogonal directions.
19. The polarization splitter of claim 17 , wherein the SiN waveguide core includes an input port to receive the input light signal and an output port to output a first output light signal including the second polarization mode, wherein the Si slot waveguide core includes an output port to output a second output light signal including the first polarization mode.
20. The polarization splitter of claim 17 , wherein the SiN waveguide core is formed in a layer of a Si photonic integrated circuit (PIC) and the Si slot waveguide core is formed in another layer of the Si PIC.