Structured light generator and object recognition apparatus including the same

Patent metadata

Field	Value
Publication number	US-10402993-B2
Application number	US-201816040155-A
Country	US
Kind code	B2
Filing date	Jul 19, 2018
Priority date	Mar 30, 2016
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A structured light generator includes a light source configured to emit light, and a first meta optical device including a first metasurface including nanostructures having sub-wavelength dimensions that are less than a wavelength of the light emitted from the light source, the first metasurface being configured to form a distribution of light rays from the light emitted from the light source to thereby radiate structured light.

First claim

What is claimed is:

1. A structured light generator comprising:
a light source configured to emit light; and
a first meta optical device comprising a first metasurface comprising nanostructures having sub-wavelength dimensions that are less than a wavelength of the light emitted from the light source,
wherein the first metasurface is configured to form a distribution of light rays from the light emitted from the light source to thereby radiate structured light; and,
a second meta optical device provided between the light source and the first meta optical device, the second meta optical device comprising a second metasurface configured to receive the light emitted from the light source, adjust a beam shape of the light emitted from the light source, and propagate the light having the adjusted beam shape to the first meta optical device.

2. The structured light generator of claim 1 , wherein the nanostructures of the first meta optical device have forms that are configured to realize a predetermined transmission intensity distribution and transmission phase distribution with respect to the emitted light incident thereon.

3. The structured light generator of claim 1 , wherein:
the light source comprises a light exit surface through which the emitted light exits; and
the first meta optical device has a monolithic structure and is provided directly on the light exit surface of the light source.

4. The structured light generator of claim 1 , wherein the nanostructures of the first meta optical device have shapes and an arrangement that are determined such that a transmission intensity distribution and transmission phase distribution with respect to the emitted light incident thereon are repeated.

5. The structured light generator of claim 4 , wherein the nanostructures of the first meta optical device have the shapes and distribution such that two transmission phase modulation values are obtained.

6. The structured light generator of claim 5 , wherein the two transmission phase modulation values are 0 and π.

7. The structured light generator of claim 4 , wherein a distance from the light source to the first metasurface is determined such that a contrast of a structured light pattern formed by the distribution of the light rays is a maximum.

8. The structured light generator of claim 7 , wherein the distance (d) from the light source to the first metasurface satisfies the following condition:

d
=

m
⁢

⁢

2
⁢

a
1
2

λ

,

wherein λ denotes the wavelength of the light emitted from the light source, a 1 denotes a period at which a same structure is repeated in the first meta optical device, and m denotes a natural number.

9. The structured light generator of claim 1 , wherein the first meta optical device and the second meta optical device share a supporting substrate supporting the first metasurface and the second metasurface, and
the first metasurface and the second metasurface are respectively provided on different surfaces of the supporting substrate, the different surfaces facing each other.

10. The structured light generator of claim 1 , further comprising a third meta optical device comprising a third meta surface configured to repeatedly form the distribution of the light rays formed by the first meta optical device in a predetermined angular space.

11. The structured light generator of claim 1 , wherein the nanostructures have cylindrical shapes.

12. The structured light generator of claim 1 , wherein the first meta optical device is directly disposed on and in contact with the second meta optical device.

13. The structured light generator of claim 12 , wherein the nanostructures comprise a dielectric material having a refractive index greater than a refractive index of the substrate.

14. The structured light generator of claim 1 , wherein a distance from the light source to the first metasurface is set to be inversely proportional to the wavelength of the light emitted from the light source, and directly proportional to a square of a period at which a same structure is repeated in the first meta optical device.

15. The structured light generator of claim 12 , wherein some nanostructures among the nanostructures comprise a dielectric material having a refractive index greater than a refractive index of the substrate, and other nanostructures among the nanostructures comprise a conductive material.

16. A structured light generator comprising:
a light source configured to emit light;
a first meta optical device comprising a first metasurface comprising nanostructures having sub-wavelength dimensions that are less than a wavelength of the light emitted from the light source,
wherein the first metasurface is configured to form a distribution of light rays from the light emitted from the light source to thereby radiate structured light in a predetermined beam pattern; and
a third meta optical device comprising a third meta surface configured to duplicate the predetermined beam pattern of the structured light that is radiated from the first meta optical device in a predetermined angular space,
wherein the first meta optical device is disposed between the light source and the third meta optical device, so that the light rays is directly propagated from the first metasurface to the third meta surface.

17. The structured light generator of claim 16 , wherein the first meta optical device and the third meta optical device share a substrate supporting the first metasurface and the third metasurface, and
the first metasurface and the third metasurface are respectively provided on opposite surfaces of the substrate, the opposite surfaces facing each other.

18. A three-dimensional (3D) object recognition apparatus comprising:
a structured light generator of claim 1 ;
a sensor configured to receive the structured light reflected from the object; and
a processor configured to analyze a shape or motion of the object by comparing pattern changes in the structured light radiated by the structured light generator and the structured light received by the sensor.

19. A three-dimensional (3D) object recognition apparatus comprising:
a structured light generator of claim 16 ;
a sensor configured to receive the structured light reflected from the object; and
a processor configured to analyze a shape or motion of the object by comparing pattern changes in the structured light radiated by the structured light generator and the structured light received by the sensor.

20. An electronic device comprising the 3D object recognition apparatus of claim 18 .

Assignees

• Samsung Electronics Co Ltd
• California Inst Of Techn

Inventors

• Han Seunghoon
• Naqavi Ali
• Atwater Harry

Classifications

• G02B5/1809

  with pitch less than or comparable to the wavelength · CPC title

• G06T7/248

  involving reference images or patches · CPC title

• G02B1/002

  made of materials engineered to provide properties not available in nature, e.g. metamaterials · CPC title

• G02B5/00

  Optical elements other than lenses (light guides G02B6/00; optical logic elements G02F3/00) · CPC title

• G02B27/0938 Primary

  Using specific optical elements · CPC title