Lidar system with solid state spectral scanning

Patent metadata

Field	Value
Publication number	US-2020400798-A1
Application number	US-201916449189-A
Country	US
Kind code	A1
Filing date	Jun 21, 2019
Priority date	Jun 21, 2019
Publication date	Dec 24, 2020
Grant date	—

Abstract

A light detection and ranging (LIDAR) apparatus is provided that includes an optical source to emit a first optical beam having a first frequency and a second optical beam having a second frequency and a dispersive element to deflect the first optical beam having the first frequency at a first angle and the second optical beam having the second frequency at a second angle.

First claim

What is claimed is:

1 . A light detection and ranging (LIDAR) apparatus, comprising:
an optical source to emit a first optical beam having a first frequency and a second optical beam having a second frequency; and a dispersive element to deflect the first optical beam having the first frequency at a first angle and the second optical beam having the second frequency at a second angle.

2 . The LIDAR apparatus of claim 1 , wherein the dispersive element deflects the first optical beam and the second optical beam along a first axis, the LIDAR apparatus further comprising:
a scanner to deflect the first optical beam and the second optical beam along a second axis that is orthogonal to the first axis.

3 . The LIDAR apparatus of claim 1 , further comprising:
a polarization beam splitter (PBS) to pass a first polarization state of light through the PBS in a first direction and reflect a second polarization state of light in a second direction different than the first direction.

4 . The LIDAR apparatus of claim 1 , further comprising:
an optical circulator to direct the first optical beam and the second optical beam from the optical source in a first direction and direct a first target signal associated with the first optical beam and a second target signal associated with the second optical beam in a second direction.

5 . The LIDAR apparatus of claim 1 , further comprising:
a photodetector to receive a first combined signal comprising a first target signal and first local oscillator signal associated with the first optical beam and a second combined signal comprising a second target signal and second local oscillator signal associated with the second optical beam.

6 . The LIDAR apparatus of claim 5 , wherein the optical source and the photodetector are positioned on a photonic chip.

7 . The LIDAR apparatus of claim 1 , further comprising a polarization wave plate to transform a polarization state of the first optical beam and the second optical beam.

8 . The LIDAR apparatus of claim 7 , wherein the polarization wave plate comprises one of a quarter-wave plate or a half-wave plate.

9 . The LIDAR apparatus of claim 7 , wherein the polarization wave plate further comprises a reflector or a coating to return a portion of the first optical beam as a first local oscillator signal and a portion of the second optical beam as a second local oscillator signal.

10 . The LIDAR apparatus of claim 1 , wherein the first optical beam having the first frequency comprises a first linear chirp that is tuned around the first frequency and the second optical beam having the second frequency comprise a second linear chirp that is tuned around the second frequency.

11 . The LIDAR apparatus of claim 1 , further comprising:
an optical isolator comprising a tap to provide a portion of the first optical beam as a first reference signal and a portion of the second optical beam as a second reference signal to a reference arm circuit.

12 . The LIDAR apparatus of claim 11 , wherein the reference arm circuit comprises:
an interferometer to receive the first reference signal and the second reference signal; and a photodetector to receive the first reference signal and the second reference signal from the interferometer.

13 . The LIDAR apparatus of claim 12 , wherein the reference arm circuit further comprises:
a coupler to split a portion of the first reference signal to generate a first local oscillator signal and a portion of the second reference signal to generate a second local oscillator signal.

14 . A method comprising:
generating, by an optical source of a light detection and ranging (LIDAR) system, a first optical beam having a first frequency and a second optical beam having a second frequency; and providing, to a dispersive element, the first optical beam having the first frequency and the second optical beam having the second frequency, wherein the dispersive element deflects the first optical beam having the first frequency at a first angle and the second optical beam having the second frequency at a second angle.

15 . The method of claim 14 , wherein the dispersive element deflects the first optical beam and the second optical beam along a first axis, the method further comprising:
providing, to a scanner, the first optical beam and the second optical beam, wherein the scanner deflects the first optical beam and the second optical beam along a second axis that is orthogonal to the first axis.

16 . The method of claim 14 , further comprising:
splitting, by a first coupler, a portion of the first optical beam to generate a first local oscillator signal and a portion of the second optical beam to generate a second local oscillator signal; receiving a first target signal associated with the first optical beam and a second target signal associated with the second optical beam; combining, by a second coupler, the first target signal with the first local oscillator signal to generate a first combined signal, and the second target signal with the second local oscillator signal to generate a second combined signal; and providing the first combined signal and the second combined signal to a photodetector.

17 . The method of claim 14 , further comprising:
reflecting, by a reflector or a coating of a polarization wave plate, a portion of the first optical beam to generate a first local oscillator signal and the second optical beam to generate a second local oscillator signal; receiving a first target signal associated with the first optical beam and a second target signal associated with the second optical beam; combining, by a coupler, the first target signal with the first local oscillator signal to generate a first combined signal and the second target signal with the second local oscillator signal to generate a second combined signal; and providing the first combined signal and the second combined signal to a photodetector.

18 . The method of claim 14 , wherein generating the first optical beam having the first frequency and the second optical beam having the second frequency comprises:
generating a first linear chirp that is tuned around the first frequency and a second linear chirp that is tuned around the second frequency.

19 . The method of claim 14 , further comprising:
providing a portion of the first optical beam and the second optical beam as a reference signal to a reference arm circuit.

20 . The method of claim 14 , further comprising:
generating, by a plurality of optical sources of the LIDAR system, a plurality of optical beams, each of the plurality of optical beams having a different corresponding frequency.

Assignees

• Aeva Inc

Inventors

• Rezk Mina
• Kocaoglu Omer P
• Avci Oguzhan
• Oza Neal N
• Gagne Keith
• Behzadi Behsan

Classifications

• G01S17/08 Primary

  for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) · CPC title

• G01S7/4817 Primary

  relating to scanning · CPC title

• G01S7/4911 Primary

  Transmitters · CPC title

• G01S7/4814

  of transmitters alone · CPC title

• G01S7/4816

  of receivers alone · CPC title