Optical gyroscope with weak measurement amplification readout

Patent metadata

Field	Value
Publication number	US-12018944-B2
Application number	US-202318172043-A
Country	US
Kind code	B2
Filing date	Feb 21, 2023
Priority date	Oct 27, 2020
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

A photonic device for detecting rotation and a corresponding method for operation thereof are disclosed. The photonic device includes a readout structure coupled to a ring resonator at one or more coupling points. Light is split between a lower waveguide and an upper waveguide of the readout structure in a forward direction at a beam splitter. The light in the waveguides traveling in the forward direction is coupled into the ring resonator and subsequently back into the waveguides in a reverse direction. The light is spatially phase tilted and is combined at the beam splitter. The combined light is detected by a split detector.

First claim

What is claimed is:

1. A method of detecting a rotation of a photonic device, the method comprising:
inputting light at an input port formed by one or more waveguides of a readout structure;
splitting, at a beam splitter, the light between a lower path and an upper path of the one or more waveguides in a forward direction;
coupling the light in the lower path traveling in the forward direction into a ring resonator at a lower coupling point and the light in the upper path traveling in the forward direction into the ring resonator at an upper coupling point, wherein the lower path at least partially extends
past the lower coupling point in the forward direction and the upper path at least partially extends past the upper coupling point in the forward direction;
coupling the light in the ring resonator into the lower path in a reverse direction at the lower coupling point and the light in the ring resonator into the upper path in the reverse direction at the upper coupling point;
combining, at the beam splitter, the light in the lower path traveling in the reverse direction and the light in the upper path traveling in the reverse direction to form output light; and
detecting the output light at an output port formed by the one or more waveguides, wherein the rotation is calculated based on the output light.

2. The method of claim 1 , wherein the lower path and the upper path are unconnected to each other.

3. The method of claim 1 , wherein the beam splitter is formed by positioning a region of the lower path within a threshold distance of a region of the upper path.

4. The method of claim 1 , wherein the photonic device includes a light source for generating the light.

5. The method of claim 1 , wherein the ring resonator introduces a relative phase shift between the light in the lower path traveling in the reverse direction and the light in the upper path traveling in the reverse direction.

6. The method of claim 1 , further comprising calculating the rotation based on an analysis of the output light.

7. The method of claim 6 , wherein calculating the rotation based on the analysis of the output light includes:
determining an intensity difference between a first lobe and a second lobe of the output light; and
calculating the rotation based on the intensity difference.

8. The method of claim 1 , wherein the photonic device comprises a gyroscope.

9. A photonic device comprising:
a ring resonator; and
a readout structure coupled to the ring resonator at one or more coupling points, the readout structure comprising:
one or more waveguides forming:
a lower path and an upper path;
an input port coupled to the lower path or the upper path, the input port configured to receive light; and
an output port coupled to the lower path or the upper path, the output port configured to output the light;

a beam splitter for splitting the light between the lower path and the upper path in a forward direction and for combining the light in the lower path traveling in a reverse direction and the light in the upper path traveling in the reverse direction to form output light; and
a detector for detecting the output light at the output port;

wherein the photonic device is configured to:
couple the light in the lower path traveling in the forward direction into the ring resonator at a lower coupling point and the light in the upper path traveling in the forward direction into the ring resonator at an upper coupling point, wherein the lower path at least partially extends past the lower coupling point in the forward direction and the upper path at least partially extends past the upper coupling point in the forward direction; and
couple the light in the ring resonator into the lower path in a reverse direction at the lower coupling point and the light in the ring resonator into the upper path in the reverse direction at the upper coupling point.

10. The photonic device of claim 9 , wherein the lower path and the upper path are unconnected to each other.

11. The photonic device of claim 9 , wherein the beam splitter is formed by positioning a region of the lower path within a threshold distance of a region of the upper path.

12. The photonic device of claim 9 , further comprising a light source configured to generate the light.

13. The photonic device of claim 9 , wherein the ring resonator introduces a relative phase shift between the light in the lower path traveling in the reverse direction and the light in the upper path traveling in the reverse direction.

14. The photonic device of claim 9 , wherein a rotation of the photonic device is calculated based on an analysis of the output light.

15. The photonic device of claim 14 , wherein the rotation is calculated based on an intensity difference between a first lobe and a second lobe of the output light.

16. The photonic device of claim 9 , wherein the photonic device comprises a gyroscope.

Assignees

• Drs Network & Imaging Systems Llc

Inventors

• Lopez Marco A
• Jordan Andrew
• Lyons Kevin
• Steinmetz John

Classifications

• G02B6/29338

  Loop resonators · CPC title

• G01C19/662 Primary

  signal readout; dither compensators · CPC title