Optical system with polarization volume hologram

Patent metadata

Field	Value
Publication number	US-11860571-B2
Application number	US-202117528180-A
Country	US
Kind code	B2
Filing date	Nov 16, 2021
Priority date	May 20, 2019
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

A system is provided. The system includes a first PVH layer configured to deflect a first polarized light having a first handedness. The system includes a second PVH layer coupled to the first PVH layer and configured to deflect a second polarized light having a second handedness opposite to the first handedness. The system includes an optical sensor configured to generate a first image based on the first polarized light deflected by the first PVH layer and generate a second image based on the second polarized light deflected by the second PVH layer.

First claim

What is claimed is:

1. A system, comprising:
a first polarization volume hologram (PVH) layer configured to deflect a first polarized light having a first handedness;
a second PVH layer coupled to the first PVH layer and configured to deflect a second polarized light having a second handedness opposite to the first handedness; and
an optical sensor configured to generate a first image based on the first polarized light deflected by the first PVH layer, and generate a second image based on the second polarized light deflected by the second PVH layer.

2. The system of claim 1 , wherein
the first PVH layer is configured with a first helix twist of the first handedness, and
the second PVH layer is configured with a second helix twist of the second handedness.

3. The system of claim 1 , further comprising a light source configured to emit a third light that is reflected by a target as the first polarized light toward the first PVH layer, and as the second polarized light toward the second PVH layer.

4. The system of claim 1 , wherein each of the first polarized light and the second polarized light is an infrared light.

5. The system of claim 4 , further comprising:
a light source configured to emit a third light that is reflected by a target as the first polarized light toward the first PVH layer, and as the second polarized light toward the second PVH layer, wherein the third light has a first wavelength in an infrared spectrum.

6. The system of claim 5 , wherein
the light source is a first light source, and
the system further comprises:
a second light source configured to emit a fourth light that is reflected by the target toward the first PVH layer and the second PVH layer, the fourth light having a second wavelength in the infrared spectrum that is different from the first wavelength.

7. The system of claim 6 , wherein:
the first wavelength corresponds to a first Bragg period of a first Bragg grating formed by liquid crystal (LC) molecules in the first PVH layer, and
the second wavelength corresponds to a second Bragg period of a second Bragg grating formed by LC molecules in the second PVH layer.

8. The system of claim 1 , wherein the first image and the second image are different perspective views of a same region of a target.

9. The system of claim 1 , wherein the first image and the second image are images of different regions of a target.

10. The system of claim 1 , wherein the first PVH layer and the second PVH layer are included in a PVH composite film, the system further comprises:
an optical switch arranged between the PVH composite film and the optical sensor, and configured to switch between:
a first state, in which the optical switch transmits the first polarized light deflected by the first PVH layer and blocks the second polarized light deflected by the second PVH layer, and
a second state, in which the optical switch transmits the second polarized light deflected by the second PVH layer and blocks the first polarized light deflected by the first PVH layer.

11. The system of claim 1 , wherein
the first image and the second image are superimposed on each other, and
the system further comprises:
a processor configured to separate the first image and the second image based on features in the first image and the second image.

12. The system of claim 1 , wherein a first optical axis of the first PVH layer and a second optical axis of the second PVH layer extend in a same direction.

13. The system of claim 1 , wherein a first optical axis of the first PVH layer and a second optical axis of the second PVH layer extend in different directions.

14. The system of claim 1 , wherein a first field of view (FOV) of the first PVH layer encompasses a second FOV of the second PVH layer.

15. The system of claim 1 , wherein a first FOV of the first PVH layer is the same as a second FOV of the second PVH layer.

16. The system of claim 1 , wherein a first FOV of the first PVH layer and a second FOV of the second PVH layer do not encompass each other.

17. The system of claim 1 , wherein the first PVH layer and the second PVH layer have different optical powers.

18. A system, comprising:
a first polarization volume hologram (PVH) layer configured to deflect a first polarized light having a first handedness and having a first field of view (FOV); and
a second PVH layer coupled to the first PVH layer and configured to deflect a second polarized light having a second handedness opposite to the first handedness, and having a second FOV,
wherein the first FOV encompasses the second FOV.

19. The system of claim 18 , wherein a first optical axis of the first PVH layer and a second optical axis of the second PVH layer extend in a same direction.

20. The system of claim 18 , wherein a first optical axis of the first PVH layer and a second optical axis of the second PVH layer extend in different directions.

Assignees

• Meta Platforms Tech Llc

Inventors

• Ouderkirk Andrew John
• Sharma Robin
• Noble Hannah
• Amirsolaimani Babak
• Sulai Yusufu Njoni Bamaxam

Classifications

• G03H1/0248 Primary

  Volume holograms · CPC title

• G02B5/32

  Holograms used as optical elements · CPC title

• G02B27/283

  used for beam splitting or combining · CPC title

• G03H1/0256

  having specific functional layer · CPC title

• G03H2223/23

  Diffractive element · CPC title