Displaying three-dimensional objects

Patent metadata

Field	Value
Publication number	US-11415937-B2
Application number	US-202117478207-A
Country	US
Kind code	B2
Filing date	Sep 17, 2021
Priority date	Sep 17, 2020
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, an optically diffractive device includes: first and second diffractive components and a color-selective polarizer therebetween. The first diffractive component is configured to diffract a first color of light in a first polarization state incident at a first incident angle with a first diffraction efficiency at a first diffracted angle, and diffract a second color of light in a second polarization state with a diffraction efficiency substantially less than the first diffraction efficiency. The color-selective polarizer is configured to rotate the second polarization state of the second color of light to the first polarization state. The second diffractive component is configured to diffract the second color of light in the first polarization state with a second diffraction efficiency at a second diffracted angle substantially identical to the first diffracted angle.

First claim

What is claimed is:

1. An optical device comprising:
a first optically diffractive component configured to: i) diffract a first color of light in a first polarization state incident at a first incident angle with a first diffraction efficiency at a first diffracted angle; and ii) diffract a second color of light in a second polarization state incident at a second incident angle with a diffraction efficiency that is substantially smaller than the first diffraction efficiency;
a color-selective polarizer configured to rotate a polarization state of the second color of light in the second polarization state incident on the color-selective polarizer from the second polarization state to the first polarization state; and
a second optically diffractive component configured to diffract the second color of light in the first polarization state incident at the second incident angle with a second diffraction efficiency at a second diffracted angle,
wherein the color-selective polarizer is between the first and second optically diffractive components, and
wherein the optical device is configured such that the diffracted first color of light at the first diffracted angle is incident on the second optically diffractive component and transmitted through the second optically diffractive component.

2. The optical device of claim 1 , wherein the second optically diffractive component is configured to diffract the first color of light in the second polarization state at the first incident angle with a diffraction efficiency substantially smaller than the second diffraction efficiency.

3. The optical device of claim 1 , further comprising:
a third optically diffractive component; and
a second color-selective polarizer between the second and third optically diffractive components,
wherein the second color-selective polarizer is configured to: when a third color of light is incident in the second polarization state on the second color-selective polarizer, rotate a polarization state of the third color of light from the second polarization state to the first polarization state, and
wherein the third optically diffractive component is configured to: when the third color of light is incident on the third optically diffractive component at a third incident angle and in the first polarization state, diffract the third color of light at a third diffracted angle with a third diffraction efficiency.

4. The optical device of claim 3 , wherein the color-selective polarizer is configured to rotate a polarization state of the first color of light from the first polarization state to the second polarization state, and
wherein the second color-selective polarizer is configured to rotate the polarization state of the second color of light from the first polarization state to the second polarization state, without rotation of the polarization state of the first color of light.

5. The optical device of claim 3 , further comprising:
a third color-selective polarizer configured to rotate the polarization state of each of the first and second colors of light from the second polarization state to the first polarization state, without rotation of the polarization state of the third color of light,
wherein the third optically diffractive component is between the second and third color-selective polarizers.

6. The optical device of claim 3 , wherein the third optically diffractive component is configured to diffract each of the first and second colors of light incident in the second polarization state with a diffraction efficiency substantially smaller than the third diffraction efficiency,
wherein the first optically diffractive component is configured to diffract the third color of light incident in the second polarization state with a diffraction efficiency substantially smaller than the first diffraction efficiency, and
wherein the second optically diffractive component is configured to diffract each of the first and third colors of light incident in the second polarization state with a diffraction efficiency substantially smaller than the second diffraction efficiency.

7. The optical device of claim 3 , wherein the second color-selective polarizer comprises a pair of a first sub-polarizer and a second sub-polarizer,
wherein the first sub-polarizer is configured to rotate the polarization state of the second color of light from the first polarization state to the second polarization state, without rotation of the polarization state of each of the first and third colors of light, and
wherein the second sub-polarizer is configured to rotate the polarization state of the third color of light from the second polarization state to the first polarization state, without rotation of the polarization state of each of the first and second colors of light.

8. The optical device of claim 3 , further comprising:
a fourth color-selective polarizer configured to rotate a polarization state of the first color of light from the second polarization state to the first polarization state, without rotation of the polarization state of each of the second and third colors of light,
wherein the first optically diffractive component is between the fourth color-selective polarizer and the color-selective polarizer.

9. The optical device of claim 3 , wherein each of the first, second, and third optically diffractive components comprises:
a respective holographic grating formed in a recording medium,
a carrier film attached to a side of the recording medium, and
a diffraction substrate attached to another side of the recording medium opposite to the carrier film,
wherein the carrier film of the first optically diffractive component is attached to a first side of the color-selective polarizer, and the diffraction substrate of the second optically diffractive component is attached to a second, opposite side of the color-selective polarizer, and
wherein the carrier film of the second optically diffractive component is attached to a first side of the second color-selective polarizer, and the diffraction substrate of the second optically diffractive component is attached to a second, opposite side of the second color-selective polarizer.

10. The optical device of claim 3 , further comprising:
a substrate; and
an anti-reflective coating on a surface of the substrate,
wherein the first optically diffractive component is between the substrate and the color-selective polarizer.

11. The optical device of claim 1 , comprising: a front surface and a back surface, wherein the first color of light and the second color of light are incident on the front surface, and
wherein the optical device further comprises: an anti-reflective coating on the back surface.

12. The optical device of claim 1 , comprising a plurality of optical components including the first optically diffractive component, the color-selective polarizer, and the second optically diffractive component,
wherein adjacent two optical components of the plurality of optical components are attached together through a refractive index matching material.

13. The optical device of claim 1 , wherein each of the first and second optically diffractive components comprises a respective Bragg grating formed in a recording medium, and
wherein the respective Bragg grating comprises a plurality of fringe planes with a fringe tilt angle θ t and a fringe spacing Λ perpendicular to the fringe planes in a volume of the recording medium, and
wherein the respective Bragg grating is configured such that, when an incident angle on the recording medium is an on-Bragg angle, a respective diffracted angle θ m is satisfied with Bragg's equation as below:
mλ=

Assignees

• Pacific Light & Hologram Inc

Inventors

• Qaderi Kamran
• Hart Stephen John
• Hess Robert Alan
• Blackley Jonathan Seamus

Classifications

• G02B27/4272

  having plural diffractive elements positioned sequentially along the optical path · CPC title

• G03H1/2202 Primary

  Reconstruction geometries or arrangements · CPC title

• G03H1/0005

  Adaptation of holography to specific applications (holographic optical element G02B5/32; holographic scanner G02B26/106; recognition using holographic mask G06V10/88; holographic memories G11B7/0065, G11C13/042) · CPC title

• G02F1/13306

  Circuit arrangements or driving methods for the control of single liquid crystal cells (G02F1/132, G02F1/133382 take precedence) · CPC title

• G03H2001/0088

  for video-holography, i.e. integrating hologram acquisition, transmission and display · CPC title