Optical wedge in fmcw lidar optics system

Patent metadata

Field	Value
Publication number	US-2025334792-A1
Application number	US-202418649285-A
Country	US
Kind code	A1
Filing date	Apr 29, 2024
Priority date	Apr 29, 2024
Publication date	Oct 30, 2025
Grant date	—

Abstract

A LiDAR system that includes an optical wedge is disclosed herein. The LiDAR system transmits, along a Tx chief ray axis, a Tx beam that, in either order, passes through a source lens and contacts a surface of the optical wedge. The source lens is centered about the Tx chief ray axis. The optical wedge directs the Tx beam at a first angle relative to the Tx chief ray axis. The optical wedge refracts a BPLO beam at a second angle relative to the Tx chief ray axis. The second angle is different from the first angle. A system lens receives the Tx beam and the BPLO beam according to a symmetric beam footprint on the system lens.

First claim

What is claimed is:

1 . A method of using an optical wedge in a light detection and ranging (LiDAR) system, comprising:
transmitting, along a transmit (Tx) chief ray axis, a Tx beam that, in either order, passes through a source lens and contacts a surface of the optical wedge, the source lens being centered about the Tx chief ray axis; directing, by the optical wedge, the Tx beam from the optical wedge at a first angle relative to the Tx chief ray axis; refracting, by the optical wedge, a back projected local oscillator (BPLO) beam from the optical wedge at a second angle relative to the Tx chief ray axis, the second angle being different from the first angle; and receiving, at a system lens, the Tx beam and the BPLO beam according to a symmetric beam footprint on the system lens.

2 . The method of claim 1 , wherein the surface of the optical wedge is an apex surface that is molded at an apex angle, the optical wedge further including an unmolded surface at an opposite side of the optical wedge as the apex surface.

3 . The method of claim 1 , wherein the surface of the optical wedge is an unmolded surface, the optical wedge further including an apex surface molded at an apex angle at an opposite side of the optical wedge as the unmolded surface.

4 . The method of claim 1 , wherein the optical wedge is tilted from a perpendicular angle relative to the Tx chief ray axis.

5 . The method of claim 1 , wherein the optical wedge is included in an array of optical wedges comprising at least a second optical wedge, the method further comprising:
transmitting, along a second Tx chief ray axis, a second Tx beam that, in either order, passes through a second source lens and contacts a second surface of the at least the second optical wedge, the second source lens being centered about the second Tx chief ray axis.

6 . The method of claim 5 , wherein the array of optical wedges directs the Tx beam and the second Tx beam from the array of optical wedges at a same first angle as the first angle, and wherein the array of optical wedges refracts the BPLO beam and a second BPLO beam from the array of optical wedges at a same second angle as the second angle, the second BPLO beam being refracted from the second optical wedge.

7 . The method of claim 6 , wherein the Tx beam and the BPLO beam are symmetric on the system lens relative to the second Tx beam and the second BPLO beam.

8 . The method of claim 1 , wherein the symmetric beam footprint on the system lens is symmetric about an optical axis of the LiDAR system, the system lens being centered about the optical axis, the optical axis being parallel to the Tx chief ray axis.

9 . The method of claim 1 , wherein the Tx beam and the BPLO beam converge toward a target plane.

10 . A light detection and ranging (LiDAR) system including an optical wedge, the LiDAR system configured to:
transmit, along a transmit (Tx) chief ray axis, a Tx beam that, in either order, passes through a source lens and contacts a surface of the optical wedge, the source lens being centered about the Tx chief ray axis; direct by the optical wedge, the Tx beam from the optical wedge at a first angle relative to the Tx chief ray axis; refract, by the optical wedge, a back projected local oscillator (BPLO) beam from the optical wedge at a second angle relative to the Tx chief ray axis, the second angle being different from the first angle; and receive, at a system lens, the Tx beam and the BPLO beam according to a symmetric beam footprint on the system lens.

11 . The LiDAR system of claim 10 , wherein the surface of the optical wedge is an apex surface that is molded at an apex angle, the optical wedge further including an unmolded surface at an opposite side of the optical wedge as the apex surface.

12 . The LiDAR system of claim 10 , wherein the surface of the optical wedge is an unmolded surface, the optical wedge further including an apex surface molded at an apex angle at an opposite side of the optical wedge as the unmolded surface.

13 . The LiDAR system of claim 10 , wherein the optical wedge is tilted from a perpendicular angle relative to the Tx chief ray axis.

14 . The LiDAR system of claim 10 , wherein the optical wedge is included in an array of optical wedges comprising at least a second optical wedge, the LiDAR system further configured to:
transmit, along a second Tx chief ray axis, a second Tx beam that, in either order, passes through a second source lens and contacts a second surface of the at least the second optical wedge, the second source lens being centered about the second Tx chief ray axis.

15 . The LiDAR system of claim 14 , wherein the array of optical wedges directs the Tx beam and the second Tx beam from the array of optical wedges at a same first angle as the first angle, and wherein the array of optical wedges refracts the BPLO beam and a second BPLO beam from the array of optical wedges at a same second angle as the second angle, the second BPLO beam being refracted from the second optical wedge.

16 . The LiDAR system of claim 15 , wherein the Tx beam and the BPLO beam are symmetric on the system lens relative to the second Tx beam and the second BPLO beam.

17 . The LiDAR system of claim 10 , wherein the symmetric beam footprint on the system lens is symmetric about an optical axis of the LiDAR system, the system lens being centered about the optical axis, the optical axis being parallel to the Tx chief ray axis.

18 . A light detection and ranging (LiDAR) system including an array of optical wedges, the LiDAR system configured to:
transmit, along respective transmit (Tx) chief ray axes, a plurality of Tx beams including a first Tx beam and a second Tx beam, the plurality of Tx beams being, in either order, passed through an array of source lens and contacted to the array of optical wedges, each source lens in the array of source lenses being centered about the respective Tx chief ray axes; direct, by the array optical wedges, the first Tx beam and the second Tx beam at a same first angle from a local oscillator (LO) window; refract, by the array of optical wedges, a plurality of back projected local oscillator (BPLO) beams including a first BPLO beam and a second BPLO beam, the plurality of BPLO beams being refracted at a same second angle from the LO window; and receive, at a system lens, the plurality of Tx beams and the plurality of BPLO beams according to a symmetric beam footprint on the system lens.

19 . The LiDAR system of claim 18 , wherein the array of optical wedges includes an apex surface profile molded according to an apex angle and an unmolded surface profile on an opposite side of the array of optical wedges as the apex surface profile.

20 . The LiDAR system of claim 18 , wherein the array of optical wedges is tilted from a perpendicular angle relative to the respective Tx chief ray axes.

Assignees

• Aeva Inc

Inventors

• Xiao Shijun
• Smith Daniel Gene

Classifications

• 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

• G02B26/10

  Scanning systems · CPC title

• G01S7/4817

  relating to scanning · CPC title

• G02B26/0891 Primary

  forming an optical wedge · CPC title