Heterogeneous integration of curved mirror structure for passive alignment in chip-scale lidar

Patent metadata

Field	Value
Publication number	US-10976414-B2
Application number	US-201816018730-A
Country	US
Kind code	B2
Filing date	Jun 26, 2018
Priority date	Jul 12, 2017
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A chip-scale coherent lidar system includes a photonic chip that includes a light source, a transmit beam coupler to provide an output signal, and a receive beam coupler to receive a received signal based on a reflection of the output signal by a target. The system also includes a transmit beam steering device to transmit the output signal out of the system, and a receive beam steering device to obtain the received signal into the system. A transmit beam curved mirror reflects the output signal from the transmit beam coupler to the transmit beam steering device. A receive beam curved mirror reflects the received signal from the receive beam steering device to the receive beam coupler. The transmit beam curved mirror and the receive beam curved mirror are formed in a substrate that is heterogeneously integrated with the photonic chip.

First claim

What is claimed is:

1. A chip-scale coherent lidar system, comprising:
a photonic chip that includes a light source, a transmit beam coupler configured to provide an output signal, and a receive beam coupler configured to receive a received signal based on a reflection of the output signal by a target;
a transmit beam steering device configured to transmit the output signal out of the system, wherein the transmit beam steering device is implemented as a two-dimensional microelectromechanical system (MEMS) mirror;
a receive beam steering device configured to obtain the received signal into the system, wherein the receive beam steering device is implemented as a two-dimensional MEMS mirror;
a transmit beam curved mirror configured to reflect the output signal from the transmit beam coupler to the transmit beam steering device; and
a receive beam curved mirror configured to reflect the received signal from the receive beam steering device to the receive beam coupler, wherein the transmit beam curved mirror and the receive beam curved mirror are formed in a substrate that is heterogeneously integrated with the photonic chip.

2. The lidar system according to claim 1 , wherein the photonic chip includes alignment marks configured to facilitate passive alignment of the photonic chip with the substrate that includes the transmit beam curved mirror and the receive beam curved mirror.

3. The lidar system according to claim 1 , wherein the light source is configured to output a frequency modulated continuous wave as the output signal.

4. The lidar system according to claim 1 , wherein the photonic chip is formed on a packaging substrate.

5. The lidar system according to claim 4 , wherein the transmit beam steering device and the receive beam steering device are also formed on the packaging substrate.

6. The lidar system according to claim 5 , wherein the transmit beam steering device and the receive beam steering device are formed non-parallel to the photonic chip on the packaging substrate.

7. The lidar system according to claim 1 , wherein a center-to-center distance between the transmit beam curved mirror and the receive beam curved mirror is a same as a distance between the transmit beam coupler and the receive beam coupler on the photonic chip.

8. The lidar system according to claim 1 , wherein the transmit beam curved mirror is formed using lithographic techniques with a curvature configured to collimate the output signal from the transmit beam coupler, and the receive beam curved mirror is formed using lithographic techniques with a curvature configured to focus the received signal from the receive beam steering device onto the receive beam coupler of the photonic chip.

9. The lidar system according to claim 8 , wherein a second transmit beam curved mirror is stamped based on a mold formed from the transmit beam curved mirror, and a second receive beam curved mirror is stamped based on a mold formed from the receive beam curved mirror.

10. The lidar system according to claim 1 , wherein the lidar system is within or on a vehicle and is configured to detect a location and speed of an object relative to the vehicle.

11. A method of assembling a coherent lidar system, comprising:
forming a transmit curved mirror and a receive curved mirror side-by-side in a substrate as a curved mirror structure;
forming a photonic chip on a packaging substrate, the photonic chip including a light source, a transmit beam coupler configured to provide an output signal, and a receive beam coupler to receive a received signal based on a reflection of the output signal by a target; and
heterogeneously integrating the curved mirror structure with the photonic chip;
disposing a transmit beam steering device and a receive beam steering device side-by-side on the packaging substrate, wherein the transmit beam steering device and the receive beam steering device are each implemented as a two-dimensional microelectromechanical system (MEMS) mirror.

12. The method according to claim 11 , wherein the disposing the transmit beam steering device and the receive beam steering device includes separating the transmit beam steering device and the receive beam steering device by a same distance as a center-to-center distance between the transmit curved mirror and the receive curved mirror.

13. The method according to claim 11 , wherein the disposing the transmit beam steering device and the receive beam steering device is on a non-parallel plane with the photonic chip.

14. The method according to claim 11 , wherein the heterogeneously integrating the curved mirror structure with the photonic chip includes using alignment marks on the photonic chip to passively align the curved mirror structure with the photonic chip.

15. The method according to claim 11 , wherein the forming the transmit curved mirror and the receive curved mirror includes using photolithography and etching.

16. The method according to claim 15 , further comprising forming a second transmit curved mirror and a second receive curved mirror includes stamping the second transmit curved mirror and the second receive curved mirror using molds formed respectively from the transmit curved mirror and the receive curved mirror.

17. A vehicle, comprising:
a coherent lidar system comprising:
a photonic chip that includes a light source, a transmit beam coupler configured to provide an output signal, and a receive beam coupler configured to receive a received signal based on a reflection of the output signal by a target and focusing it onto a receive beam coupler on the photonic chip;
a transmit beam steering device configured to transmit the output signal out of the system, wherein the transmit beam steering device is implemented as a two-dimensional microelectromechanical system (MEMS) mirror;
a receive beam steering device configured to obtain the received signal into the system, wherein the receive beam steering device is implemented as a two-dimensional MEMS mirror;
a transmit beam curved mirror configured to reflect the output signal from the transmit beam coupler to the transmit beam steering device; and
a receive beam curved mirror configured to reflect the received signal from the receive beam steering device to the receive beam coupler, wherein the transmit beam curved mirror and the receive beam curved mirror are formed in a substrate that is heterogeneously integrated with the photonic chip; and

a vehicle controller configured to use information from the lidar system to augment or automate vehicle systems.

18. The vehicle according to claim 17 , wherein the transmit beam steering device and the receive beam steering device are formed non-parallel to the photonic chip on the packaging substrate.

19. The vehicle according to claim 17 , wherein a center-to-center distance between the transmit beam curved mirror and the receive beam curved mirror is a same as a distance between the transmit beam coupler and the receive beam coupler on the photonic chip.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Sayyah Keyvan
• Efimov Oleg
• Patterson Pamela
• Sarkissian Raymond
• Schaffner James H
• Huang Biqin
• Hammon David

Classifications

• H10W46/607

  Located on parts of packages, e.g. on encapsulations or on package substrates · CPC title

• H10W46/301

  for alignment · CPC title

• H10W46/00

  Marks applied to devices, e.g. for alignment or identification · CPC title

• G02B6/1228

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

• H10F77/413

  directly associated or integrated with the devices, e.g. back reflectors (directly associated or integrated with photovoltaic cells H10F77/42) · CPC title