Optical scanner and detector

Patent metadata

Field	Value
Publication number	US-11112491-B2
Application number	US-201816022525-A
Country	US
Kind code	B2
Filing date	Jun 28, 2018
Priority date	Jun 29, 2017
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

A light ranging and detection system achieving reconfigurable very wide field of view, high sampling of spatial points per second with high optical power handling by using architecture to efficiently combine different wavelengths, time and frequency coding, and spatial selectivity. The transmitter is capable of generating multiple narrow beams, encoding different beams and transmitting in different spatial directions. The receiver can differentiate and extract range and reflectivity information of reflected beams. Three dimensional imaging of the environment is achieved by scanning the field of view of the transmitter. Control and signal processing electronic circuitries fabricated in a chip are packaged together with a chip containing the photonic components of the ranging system.

First claim

What is claimed is:

1. A device comprising a plurality of optical scanners, each of the optical scanners comprising an optical phased array, each of the optical scanners comprising:
a power splitter configured to split light from a waveguide connecting at least one laser to a plurality of waveguides;
a plurality of amplitude modulators or phase modulators, each connected to the power splitter through a corresponding waveguide of the plurality of waveguides;
a plurality of emitters, each emitter connected to a corresponding amplitude or phase modulator through a corresponding waveguide; and
a plurality of lasers, each laser operating at a different wavelength relative to other lasers of the plurality of lasers, and further comprising at least one switch between the plurality of lasers and the power splitter, configured to switch between lasers of the plurality of lasers,
wherein:
the plurality of amplitude modulators or phase modulators is configured to receive control signals to control an amplitude or phase of the light,
the optical phased array is configured to emit a light beam in a spatial direction based on the amplitude or phase of the light, and
wherein each optical scanner of the plurality of optical scanners is configured to transmit light in a spatial direction different from other optical scanners of the plurality of optical scanners.

2. The device of claim 1 , wherein each spatial direction is parametrized by a first radiation angle and a second radiation angle, and each optical scanner of the plurality of optical scanners is configured to transmit light with a different first radiation angle or second radiation angle relative to adjacent optical scanners of the plurality of optical scanners.

3. The device of claim 1 , further comprising a plurality of encoders, each encoder configured to encode light of an optical scanner.

4. The device of claim 1 , wherein each emitter of the plurality of emitters comprises a grating coupler.

5. A device comprising a plurality of optical scanners, each of the optical scanners comprising an optical phased array, each of the optical scanners comprising:
a power splitter configured to split light from a waveguide connecting at least one laser to a plurality of waveguides;
a plurality of amplitude modulators or phase modulators, each connected to the power splitter through a corresponding waveguide of the plurality of waveguides;
a plurality of emitters, each emitter connected to a corresponding amplitude or phase modulator through a corresponding waveguide; and
a plurality of lasers, each laser operating at a different wavelength relative to other lasers of the plurality of lasers, and further comprising at least one multiplexer between the plurality of lasers and the power splitter, configured to multiplex light from the plurality of lasers,
wherein:
the plurality of amplitude modulators or phase modulators is configured to receive control signals to control an amplitude or phase of the light, and
the optical phased array is configured to emit a light beam in a spatial direction based on the amplitude or phase of the light.

6. The device of claim 5 , wherein the at least one multiplexer is an arrayed waveguide grating.

7. The device of claim 3 , wherein the plurality of encoders is configured to encode amplitude of the light, phase of the light, or both amplitude and phase of the light.

8. The device of claim 1 , wherein the plurality of lasers operates in pulsed mode.

9. The device of claim 1 , wherein the plurality of lasers operates in continuous wave frequency modulated mode.

10. The device of claim 1 , wherein the device comprises Si, and a thickness of Si decreases progressively from a first side of the device comprising the plurality of lasers, to a second side of the device comprising the plurality of emitters.

11. The device of claim 10 , wherein the thickness of Si at the first side is 3 micrometers, and the thickness of Si at the second side is 1 micrometer.

12. A system comprising the device of claim 7 , and a receiver, the receiver comprising:
a broadband receiver configured to receive light reflected from objects in an environment after emission from the optical phased array;
a plurality of decoders configured to decode amplitude or phase coding of the plurality of encoders; and
a digital signal processing unit configured to determine ranging from the receiver to the objects.

13. A method comprising:
generating light by at least one laser;
selecting a wavelength of the light;
splitting light from the at least one laser to a plurality of encoders;
encoding the light in a pattern by the plurality of encoders; and
transmitting the light in a spatial direction by an optical phased array comprising a plurality of emitters, each emitter connected to a corresponding encoder of the plurality of encoders through a corresponding waveguide,
wherein the at least one laser comprises a plurality of lasers, each laser operating at a different wavelength, and
selecting a wavelength comprises activating at least one switch to switch between lasers of the plurality of lasers.

14. The method of claim 13 , further comprising:
receiving light reflected by objects in an environment after transmission by the optical phased array;
decoding the received light; and
calculating a range of and reflectivity from the objects.

15. The method of claim 13 , wherein the pattern comprises an amplitude, phase, quantity, duration and period of square wave pulses.

16. A method comprising:
generating light by at least one laser;
selecting a wavelength of the light;
splitting light from the at least one laser to a plurality of encoders;
encoding the light in a pattern by the plurality of encoders; and
transmitting the light in a spatial direction by an optical phased array comprising a plurality of emitters, each emitter connected to a corresponding encoder of the plurality of encoders through a corresponding waveguide, wherein:
the at least one laser comprises a plurality of lasers, each laser operating at a different wavelength, and splitting light from the at least one laser to a plurality of encoders comprises:
transmitting light from the plurality of lasers to at least one passive multiplexer;
transmitting light from the at least one passive multiplexer to a splitter; and
transmitting light from the splitter to the plurality of encoders.

17. The method of claim 16 , further comprising:
receiving light reflected by objects in an environment after transmission by the optical phased array;
decoding the received light; and
calculating a range of and reflectivity from the objects.

18. The method of claim 16 , wherein the pattern comprises an amplitude, phase, quantity, duration and period of square wave pulses.

19. The device of claim 5 , wherein each spatial direction is parametrized by a first radiation angle and a second radiation angle, and each optical scanner of the plurality of optical scanners is configured to transmit light with a different first radiation angle or second radiation angle relative to adjacent optical scanners of the plurality of optical scanners.

Assignees

• Rockley Photonics Ltd

Inventors

• Abediasl Hooman
• Rickman Andrew George

Classifications

• G01S17/32

  using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated · CPC title

• G01S7/484 Primary

  Transmitters · CPC title

• G02B26/106

  having diffraction gratings as scanning elements, e.g. holographic scanners (holographic optical elements G02B5/32, holography G03H) · CPC title

• H01Q3/22

  varying the orientation in accordance with variation of frequency of radiated wave · CPC title

• G02B26/101

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title