Laser beam control in a LIDAR system

Patent metadata

Field	Value
Publication number	US-11614541-B2
Application number	US-201916570538-A
Country	US
Kind code	B2
Filing date	Sep 13, 2019
Priority date	Sep 13, 2019
Publication date	Mar 28, 2023
Grant date	Mar 28, 2023

Abstract

This disclosure describes techniques for operating a lidar device. The techniques include emitting light resulting in a plurality of non-parallel laser beam waves; directing the plurality of non-parallel laser beam waves towards a laser beam scanner; reflecting the non-parallel plurality of beam waves by the laser beam scanner towards a collimator device; collimating, with the collimator device, the plurality of non-parallel laser beam waves reflected by the laser beam scanner into a corresponding plurality of parallel plane waves; and directing the plurality of plane waves from the collimator device towards a field of interest.

First claim

What is claimed is:

1. A lidar device comprising:
a laser beam source configured to emit light resulting in a plurality of non-parallel laser beam waves;
a laser beam scanner; and
one or more lenses configured to direct the plurality of non-parallel laser beam waves towards the laser beam scanner, the laser beam scanner being configured to reflect the non-parallel plurality of beam waves towards a collimator device;
the collimator device being configured to:
collimate the plurality of non-parallel laser beam waves reflected by the laser beam scanner into a corresponding plurality of parallel plane waves; and
direct the plurality of plane waves comprising a beam width towards a field of interest, wherein the beam width is set based on a relative distance between the collimator device and the laser beam scanner.

2. The lidar device of claim 1 , wherein the plurality of non-parallel laser beam waves are spherical waves.

3. The lidar device of claim 2 , wherein the plurality of non-parallel laser beam waves directed by the one or more lenses converge at different angles at the laser beam scanner.

4. The lidar device of claim 1 , wherein the laser beam scanner is configured to linearly phase shift the plurality of non-parallel laser beam waves by rotating about an axis of the laser beam scanner.

5. The lidar device of claim 4 , wherein the collimator device comprises a fixed array of parabolic reflectors with each reflector configured to collimate the laser beam toward one of a plurality of directions.

6. The lidar device of claim 4 , wherein the collimator device is actively synchronized with the laser beam scanner by changing operation of the collimator device as the laser beam scanner rotates about the axis of the laser beam scanner.

7. The lidar device of claim 6 , wherein the collimator device comprises an active phase change device comprising a plurality of phase change devices, wherein different sets of the phase change devices are activated to change a refractive index of the phase change devices as the laser beam scanner rotates about the axis of the laser beam scanner so as to collimate the linearly phase shifted plurality of non-parallel laser beam waves into the corresponding plurality of parallel plane waves, wherein the refractive index of the different sets of the phase change devices is changed using a plurality of electrodes.

8. The lidar device of claim 6 , wherein the collimator device comprises an active phase change device comprising a layer of phase-change material (PCM) and a plurality of electrodes, wherein different sets of the electrodes are activated as the laser beam scanner rotates about the axis of the laser beam scanner so as to collimate the linearly phase shifted plurality of non-parallel laser beam waves into the corresponding plurality of parallel plane waves.

9. The lidar device of claim 6 , wherein the collimator device comprises a bendable mirror that actively bends as the laser beam scanner rotates about the axis of the laser beam scanner so as to collimate the linearly phase shifted plurality of non-parallel laser beam waves into the corresponding plurality of parallel plane waves.

10. A method for operating a lidar device, the method comprising:
emitting light resulting in a plurality of non-parallel laser beam waves;
directing the plurality of non-parallel laser beam waves towards a laser beam scanner;
reflecting the non-parallel plurality of beam waves by the laser beam scanner towards a collimator device;
collimating, with the collimator device, the plurality of non-parallel laser beam waves reflected by the laser beam scanner into a corresponding plurality of parallel plane waves; and
directing the plurality of plane waves comprising a beam width from the collimator device towards a field of interest, wherein the beam width is set based on a relative distance between the collimator device and the laser beam scanner.

11. The method of claim 10 , wherein an individual parallel plane wave of the plurality of parallel plane waves originates from a point on the collimator device where an individual one of the plurality of non-parallel laser beam waves is received by the collimator device.

12. The method of claim 10 , wherein the laser beam scanner is configured to linearly phase shift the plurality of non-parallel laser beam waves by rotating about an axis of the laser beam scanner.

13. The method of claim 12 , wherein the collimator device comprises a fixed array of parabolic reflectors with each reflector configured to collimate the laser beam toward one of a plurality of directions.

14. The method of claim 12 , further comprising actively synchronizing the collimator device with the laser beam scanner by changing operation of the collimator device as the laser beam scanner rotates about the axis of the laser beam scanner.

15. The method of claim 14 , wherein the collimator device comprises an active phase change device comprising a plurality of phase change devices, further comprising activating different sets of the phase change devices to change a refractive index of the phase change devices as the laser beam scanner rotates about the axis of the laser beam scanner so as to collimate the linearly phase shifted plurality of non-parallel laser beam waves into the corresponding plurality of parallel plane waves, wherein the refractive index of the different sets of the phase change devices is changed using a plurality of electrodes.

16. A lidar device apparatus comprising:
means for emitting light resulting in a plurality of non-parallel laser beam waves;
means for directing the plurality of non-parallel laser beam waves towards a laser beam scanner;
means for reflecting the non-parallel plurality of beam waves by the laser beam scanner towards a collimator device;
means for collimating, with the collimator device, the plurality of non-parallel laser beam waves reflected by the laser beam scanner into a corresponding plurality of parallel plane waves; and
means for directing the plurality of plane waves comprising a beam width from the collimator device towards a field of interest, wherein the beam width is set based on a relative distance between the collimator device and the laser beam scanner.

17. The lidar device apparatus of claim 16 , wherein the collimator device comprises an active phase change device comprising a plurality of phase change devices, wherein different sets of the phase change devices are activated to change a refractive index of the phase change devices as the laser beam scanner rotates about an axis of the laser beam scanner so as to collimate the plurality of non-parallel laser beam waves into the corresponding plurality of parallel plane waves, wherein the refractive index of the different sets of the phase change devices is changed using a plurality of electrodes.

18. The lidar device apparatus of claim 17 , wherein the beam width remains constant as the laser beam scanner rotates about an axis of the laser beam scanner.

19. The lidar device apparatus of claim 16 , wherein the plurality of non-parallel laser beam waves converge at different angles at the laser beam scanner.

20. The lidar device apparatus of claim 16 , wherein the laser beam scanner is configured to linearly phase shift the plurality of non-parallel laser beam waves by rotating about an axis of the laser beam scanner.

Assignees

• Analog Devices Inc

Inventors

• Jia Kemiao

Classifications

• G02B27/16

  used as aids for focusing · CPC title

• G02B27/30

  Collimators · CPC title

• G02B26/10

  Scanning systems · CPC title

• G01S7/4817

  relating to scanning · CPC title

• G01S7/4814 Primary

  of transmitters alone · CPC title