Polarization splitter-rotator having silicon based waveguide with silicon nitride segment

Patent metadata

Field	Value
Publication number	US-2024241237-A1
Application number	US-202418615890-A
Country	US
Kind code	A1
Filing date	Mar 25, 2024
Priority date	Dec 21, 2020
Publication date	Jul 18, 2024
Grant date	—

Abstract

A polarization splitter-rotator (PSR) is described. The PSR having a silicon nitride based waveguide including a first silicon nitride segment comprising a tapered width in a longitudinal direction and a ridge extending in a transverse direction and an adiabatic coupler coupled with the first silicon nitride segment.

First claim

What is claimed is:

1 . A polarization splitter-rotator (PSR), comprising:
a silicon nitride based waveguide comprising:
a first silicon nitride segment comprising a tapered width in a longitudinal direction and a ridge extending in a transverse direction; and
an adiabatic coupler coupled with the first silicon nitride segment.

2 . The PSR of claim 1 , wherein the first silicon nitride segment comprises a first layer and a second layer.

3 . The PSR of claim 2 , wherein the first layer comprises a first section and a second section, wherein the first section extends from a first end of the first silicon nitride segment to a converging plane with increasing width.

4 . The PSR of claim 2 , wherein the adiabatic coupler passes a first fundamental transverse electric (TE0) mode of an optical beam through a first path and a second TE0 mode of the optical beam through a second path.

5 . The PSR of claim 2 , wherein the second layer comprises the ridge, wherein the ridge extends above the first layer.

6 . The PSR of claim 2 , wherein a width of the first layer is less than a width of the second layer.

7 . The PSR of claim 3 , wherein a length of the first section is larger than a length of the second section.

8 . The PSR of claim 2 , wherein a thickness of the first layer is from 300 nanometers (nm) to 600 nm, and wherein a thickness of the second layer is from 100 nm to 500 nm.

9 . The PSR of claim 2 , wherein the first layer has a width from 500 nanometers (nm) to 2000 nm, and wherein the second layer has a maximum width from 1000 nm to 3000nm.

10 . The PSR of claim 2 , wherein the first layer has a length from 500 micron (μm) to 5000 μm, and wherein the second layer has a length from 500 μm to 5000 μm.

11 . A light detection and ranging (LiDAR) system, comprising:
a polarization splitter-rotator (PSR) comprising a silicon nitride based waveguide to split and rotate a target return signal of an optical beam from a target, the silicon nitride based waveguide comprising a first silicon nitride segment, the first silicon nitride segment comprising a first silicon nitride segment comprising a tapered width in a longitudinal direction and a ridge extending in a transverse direction; and an adiabatic coupler coupled with the first silicon nitride segment.

12 . The LIDAR system of claim 11 , further comprising:
an optical element to generate a local oscillator (LO) signal from the optical beam; and an optical detector to mix the target return signal with the LO signal to generate a heterodyne signal to extract range and velocity information of the target.

13 . The LiDAR system of claim 11 , wherein the first silicon nitride segment comprises a first layer and a second layer.

14 . The LiDAR system of claim 13 , wherein the first layer comprises a first section and a second section, wherein the first section extends from a first end of the first silicon nitride segment to a converging plane with increasing width.

15 . The LiDAR system of claim 13 , wherein the adiabatic coupler passes a first fundamental transverse electric (TE0) mode of the optical beam through a first path and a second TE0 mode of the optical beam through a second path.

16 . The LiDAR system of claim 13 , wherein the second layer comprises the ridge, wherein the ridge extends above the first layer.

17 . The LiDAR system of claim 13 , wherein a width of the first layer is less than a width of the second layer.

18 . The LiDAR system of claim 14 , wherein a length of the first section is larger than a length of the second section.

19 . The LiDAR system of claim 13 , wherein a thickness of the first layer is from 300 nanometers (nm) to 600 nm, and wherein a thickness of the second layer is from 100 nm to 500 nm.

20 . The LiDAR system of claim 13 , wherein the first layer has a width from 500 nanometers (nm) to 2000 nm, and wherein the second layer has a maximum width from 1000 nm to 3000 nm.

Assignees

• Aeva Inc

Inventors

• Shen Bing
• Masuda Kevin
• Huff Brett E
• Srinivasan Pradeep

Classifications

• G02B6/1228

  Tapered waveguides, e.g. integrated spot-size transformers (for coupling with fibres G02B6/305) · CPC title

• G02B2006/1215

  Splitter · CPC title

• G01S17/06

  Systems determining position data of a target · CPC title

• G02B2006/12138

  Sensor · CPC title

• G02B6/126

  using polarisation effects {(G02B6/1226 takes precedence)} · CPC title