Lidar system with a mode field expander

Patent metadata

Field	Value
Publication number	US-2020300980-A1
Application number	US-201916359217-A
Country	US
Kind code	A1
Filing date	Mar 20, 2019
Priority date	Mar 20, 2019
Publication date	Sep 24, 2020
Grant date	—

Abstract

A light detection and ranging (LIDAR) apparatus is provided that includes an optical source to emit an optical beam towards a target. The LIDAR apparatus further includes a mode field expander operatively coupled to the optical source to expand a mode area of the optical beam.

First claim

What is claimed is:

1 . A light detection and ranging (LIDAR) apparatus, comprising:
an optical source to emit an optical beam towards a target; and a mode field expander operatively coupled to the optical source to expand a mode area of the optical beam.

2 . The LIDAR apparatus of claim 1 , further comprising:
a first beam separator operatively coupled between the optical source and the mode field expander, the first beam separator to separate a first portion of the optical beam in a first direction towards the target and a second portion of the optical beam in a second direction as a local oscillator signal.

3 . The LIDAR apparatus of claim 2 , further comprising:
a beam combiner to generate a combined signal comprising the local oscillator signal and a target signal associated with the optical beam.

4 . The LIDAR apparatus of claim 3 , further comprising:
a photodetector operatively coupled to the beam combiner to receive the combined signal from the beam combiner.

5 . The LIDAR apparatus of claim 3 , wherein the mode field expander is operatively coupled between at least one optical device and the beam combiner, wherein the mode field expander receives the target signal from the at least one optical device, expands the mode area of the target signal and provides the target signal to the beam combiner.

6 . The LIDAR apparatus of claim 1 , further comprising:
a polarization beam splitter operatively coupled between the optical source and the mode field expander, the polarization beam splitter to pass a first polarization state of light through the polarization beam splitter in a first direction and reflect a second polarization state of light in a second direction different than the first direction.

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

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

9 . The LIDAR apparatus of claim 1 , further comprising:
a second optical source to emit a second optical beam towards the target, wherein a first wavelength of the optical beam is different than a second wavelength of the second optical beam.

10 . The LIDAR apparatus of claim 1 , further comprising:
an optical amplifier operatively coupled between the optical source and the mode field expander, the optical amplifier to amplify the optical beam.

11 . The LIDAR apparatus of claim 1 , wherein the at least one of the optical source or the mode field expander are implemented in a photonic chip.

12 . A method comprising:
generating, by an optical source of a light detection and ranging (LIDAR) system, an optical beam towards a target; and converting, by a mode field expander operatively coupled to the optical source, a mode area associated with the optical beam.

13 . The method of claim 12 , further comprising:
receiving, by a beam separator operatively coupled between the optical source and the mode field expander, the optical beam; and separating, by the first beam separator, a first portion of the optical beam in a first direction towards the target and a second portion of the optical beam in a second direction as a local oscillator signal.

14 . The method of claim 13 , further comprising:
receiving, by a beam combiner, a target signal associated with the optical beam and the local oscillator signal; and generating, by the beam combiner, a combined signal comprising the target signal and the local oscillator signal.

15 . The method of claim 14 , further comprising:
receiving, by a photodetector, the combined signal from the second beam separator.

16 . The method of claim 12 , further comprising:
transforming, by a polarization wave plate, a polarization of the optical beam.

17 . The method of claim 12 , further comprising:
generating, by a second optical source of the LIDAR system, a second optical beam towards the target, wherein the second optical beam has a different wavelength than the optical beam; and converting, by the mode field expander, a second mode area associated with the second optical beam.

18 . The method of claim 12 , wherein the mode field expander comprises an adiabatic mode expander.

19 . The method of claim 12 , further comprising:
receiving, by the mode field expander, a target signal associated with the optical beam; and converting a second mode area associated with the target signal.

20 . The method of claim 12 , further comprising:
amplifying, by an optical amplifier operatively coupled between the optical source and the mode field expander, the optical beam generated by the optical source.

Assignees

• Aeva Inc

Inventors

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

Classifications

• G01S17/42 Primary

  Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) · CPC title

• G01S17/34

  using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal · CPC title

• G01S7/481

  Constructional features, e.g. arrangements of optical elements · CPC title

• G01S7/48 Primary

  of systems according to group G01S17/00 · CPC title

• G01S7/4818

  using optical fibres · CPC title