Beamsplitter architecture for monostatic LiDAR

Patent metadata

Field	Value
Publication number	US-11953625-B2
Application number	US-202016773145-A
Country	US
Kind code	B2
Filing date	Jan 27, 2020
Priority date	Jan 27, 2020
Publication date	Apr 9, 2024
Grant date	Apr 9, 2024

Abstract

A LiDAR system includes a light source and an arrayed micro-optic configured to receive light from the light source so as to produce and project a two-dimensional array of light spots on a scene. The LiDAR system also includes receiver optics having an array of optical detection sites configured so as to be suitable for establishing a one-to-one correspondence between light spots in the two-dimensional array and optical detection sites in the receiver optics. The LiDAR system further includes a beamsplitter and a lens. The LiDAR system may also include a mask placed in the light path between the beamsplitter and the receiver optics. Alternatively, the LiDAR system may include a controller programmed to activate or deactivate each optical detection site.

First claim

What is claimed is:

1. A light detection and ranging (LiDAR) system comprising:
a light source;
an arrayed micro-optic defining an array of optical emission sites and configured to receive light from the light source so as to produce and project a two-dimensional array of light spots on a scene;
receiver optics having an array of optical detection sites assigned and aligned to each emission site to establish a one-to-one correspondence between the light spots in the two-dimensional array and the optical detection sites in the receiver optics; and
a beamsplitter and a lens arranged so that light travels from the arrayed micro-optic to the beamsplitter, from the beamsplitter to the lens, and from the lens to the scene and further so that light reflected from the scene travels from the scene to the lens, from the lens to the beamsplitter, and from the beamsplitter to the receiver optics.

2. The LiDAR system of claim 1 , further comprising a mask having an array of apertures placed in the light path between the beamsplitter and the receiver optics, wherein each of the apertures is placed in front of a respective one of the optical detection sites.

3. The LiDAR system of claim 2 , wherein the mask is built into the receiver optics.

4. The LiDAR system of claim 2 , wherein the mask comprises a metal layer having a plurality of openings, each opening being in the light path leading to a respective one of the optical detection sites.

5. The LiDAR system of claim 4 , wherein the metal is aluminum or copper.

6. The LiDAR system of claim 1 , wherein a shape of at least one of the apertures corresponds to a shape of a light spot received at the respective optical detection site.

7. The LiDAR system of claim 1 , wherein a shape of at least one of the apertures is different from a shape of another one of the apertures.

8. The LiDAR system of claim 1 , wherein a shape of least one of the apertures is selected to mitigate variations in manufacturing of the respective optical detection site or a thermal shift of the respective optical detection site.

9. The LiDAR system of claim 1 , wherein the beamsplitter is a polarization selective beamsplitter.

10. A light detection and ranging (LiDAR) system comprising:
a light source;
an arrayed micro-optic defining an array of optical emission sites and configured to receive light from the light source so as to produce and project a two-dimensional array of light spots on a scene;
receiver optics having an array of optical detection sites assigned and aligned to each emission site to establish a one-to-one correspondence between light spots in the two-dimensional array and optical detection sites in the receiver optics;
a beamsplitter and a lens arranged so that light travels from the arrayed micro-optic to the beamsplitter, from the beamsplitter to the lens, and from the lens to the scene and further so that light reflected from the scene travels from the scene to the lens, from the lens to the beamsplitter, and from the beamsplitter to the receiver optics; and
a controller,
wherein the controller is programmed to selectively activate or deactivate each one of the optical detection sites in the array of optical detection sites.

11. The LiDAR system of claim 10 , wherein a size of each optical detection site is smaller than a size of each light spot projected onto the receiver optics.

12. The LiDAR system of claim 10 , wherein the optical detection sites are SPAD detectors.

13. The LiDAR system of claim 10 , wherein the optical detection sites are SiPM detectors.

14. The LiDAR system of claim 10 , further comprising an array of lenslets placed in a light path between the beamsplitter and the receiver optics, wherein each lenslet is placed in front of a respective one of the optical detection sites.

15. The LiDAR system of claim 10 , wherein the arrayed micro-optic comprises an array of optical emission sites and wherein the controller is further configured to selectively activate or deactivate each one of the optical emission sites in the array of optical emission sites.

16. The LiDAR system of claim 15 , wherein an activation state of at least one of the array of optical emission sites determines an activation state of an associated at least one of the optical detection sites in the array of optical detection sites.

17. A light detection and ranging (LiDAR) system comprising:
a light source;
an arrayed micro-optic defining an array of optical emission sites and configured to receive light from the light source so as to produce and project a two-dimensional array of light spots on a scene;
receiver optics having an array of optical detection sites configured assigned and aligned to each emission site to establish a one-to-one correspondence between the light spots in the two-dimensional array and the optical detection sites in the receiver optics;
a lens; and
a beamsplitter, disposed between the arrayed micro-optic and the lens, the arrayed micro-optic being located on one side of the beamsplitter, the receiver optics being located on the other side of the beamsplitter, such that the arrayed micro-optic and the optical detection sites are approximately aligned to form a mirror-image pair with respect to a semi-reflective surface of the beamsplitter, the beamsplitter configured such that outgoing light travels from the arrayed micro-optic to the beamsplitter, from the beamsplitter to the lens, and from the lens to the scene and incoming light reflected from the scene travels from the scene to the lens, from the lens to the beamsplitter, and from the beamsplitter to the receiver optics.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Moebius Michael G
• Benney Lucas D
• Spector Steven J
• Byrnes Steven J

Classifications

• G01S7/4816 Primary

  of receivers alone · CPC title

• G01S7/4917

  superposing optical signals in a photodetector, e.g. optical heterodyne detection · CPC title