Time-of-flight light source, time-of-flight imaging sensor, time-of-flight device and method

Patent metadata

Field	Value
Publication number	US-2022011435-A1
Application number	US-201917294324-A
Country	US
Kind code	A1
Filing date	Nov 14, 2019
Priority date	Nov 22, 2018
Publication date	Jan 13, 2022
Grant date	—

Abstract

The present disclosure pertains to a light source for a time-of-flight device having a vertical-cavity surface-emitting laser. The vertical-cavity surface-emitting laser has a liquid crystal section for providing light generated by the vertical-cavity surface-emitting laser at two or more distant wave-lengths.

First claim

1 . A light source for a time-of-flight device, comprising:
a vertical-cavity surface-emitting laser including a liquid crystal section for providing light generated by the vertical-cavity surface-emitting laser at two or more distant wavelengths.

2 . The light source of claim 1 , wherein the liquid crystal section is located within the vertical-cavity surface-emitting laser.

3 . The light source of claim 2 , wherein the vertical-cavity surface-emitting laser further includes a top reflector part and a bottom reflector part, wherein the liquid crystal section is located between the top reflector part and the bottom reflector part.

4 . The light source of claim 3 , wherein the vertical-cavity surface-emitting laser further includes an active section for generating the light, wherein the liquid crystal section is located between the top reflector part and the active section.

5 . The light source of claim 4 , wherein the vertical-cavity surface-emitting laser further includes a semiconductor substrate, wherein the bottom reflector part is located on the semiconductor substrate.

6 . The light source of claim 5 , wherein the vertical-cavity surface-emitting laser further includes an electrode and a current distributer configured to distribute current from the electrode, wherein the current distributer is located between the active section and the bottom reflector part.

7 . The light source of claim 6 , wherein the vertical-cavity surface-emitting laser further includes an injector configured to inject a current into the active section, wherein the injector is located adjacent to the current distributer.

8 . The light source of claim 7 , wherein the vertical-cavity surface-emitting laser further includes at least one spacer for adjusting tunnel junction, wherein the spacer are located between the liquid crystal section and the active section.

9 . The light source of claim 8 , wherein the vertical-cavity surface-emitting laser further includes two tunnel junctions, wherein the two tunnel junctions are at least partially surrounded by the spacer.

10 . The light source of claim 9 , wherein the vertical-cavity surface-emitting laser further includes at least one spreader for spreading the current injected, wherein the spreader is located between the liquid crystal section and the spacer.

11 . The light source of claim 1 , wherein the liquid crystal section is made of a nematic liquid crystal material.

12 . An imaging sensor for a time-of-flight device, comprising:
an imaging portion; and a liquid crystal portion for transferring light at two or more distant wavelengths to the imaging portion.

13 . The imaging sensor of claim 12 , wherein the liquid crystal portion is arranged on the imaging portion.

14 . The imaging sensor of claim 13 , wherein the liquid crystal portion is made of a nematic liquid crystal material.

15 . A time-of-flight device, comprising:
a light source, including:
a vertical-cavity surface-emitting laser including a liquid crystal section for providing light generated by the vertical-cavity surface-emitting laser at two or more distant wavelengths;
an imaging sensor, including:
an imaging portion; and
a liquid crystal portion for transferring light at two or more distant wavelengths to the imaging portion; and
a control configured to adjust the operating wavelength of the light source and the imaging sensor.

16 . The time-of-flight device of claim 15 , wherein the control is further configured to adjust the operating wavelength of the light source and the imaging sensor based on a predefined parameter.

17 . The time-of-flight device of claim 16 , further including:
a light sensor configured to detect an ambient light, wherein predefined parameter is indicative of the ambient light.

18 . The time-of-flight device of claim 16 , further including:
a temperature sensor configured to detect an ambient temperature, wherein the predefined parameter is indicative of the ambient temperature.

19 . The time-of-flight device of claim 16 , wherein the predefined parameter is indicative of an operating wavelength of a light source of another time-of-flight device.

20 . A time-of-flight method, comprising:
driving a light source including a vertical-cavity surface-emitting laser including a liquid crystal section for providing light generated by the vertical-cavity surface-emitting laser at two or more distant wavelengths, driving an imaging sensor including an imaging portion, and a liquid crystal portion for transferring light at two or more distant wavelengths to the imaging portion; and adjusting the operating wavelength of the light source and the imaging sensor.

Assignees

• Sony Semiconductor Solutions Corp

Inventors

• Belmonte Palermo Carlos

Classifications

• G01S7/481

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

• G01S7/4816

  of receivers alone · CPC title

• G01S17/894 Primary

  Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar · CPC title

• H01S5/423

  having a vertical cavity · CPC title

• H01S5/183 Primary

  having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL] · CPC title