Holographically displaying three-dimensional objects

Patent metadata

Field	Value
Publication number	US-12230176-B2
Application number	US-202418907386-A
Country	US
Kind code	B2
Filing date	Oct 4, 2024
Priority date	May 12, 2023
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

Methods, apparatus, devices, subsystems, and systems for holographically displaying three-dimensional objects are provided. In one aspect, an optical device includes: an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device; an in-coupling diffractive structure configured to diffract the light to propagate in the optical guiding device; and out-coupling diffractive structures configured to diffract at least part of the light out of the optical guiding device along a second direction different from the first direction. The out-coupling diffractive structures are configured to have gradually increased diffraction efficiencies for the light along the first direction away from the in-coupling diffractive structure. A first diffraction efficiency of the in-coupling diffractive structure is no smaller than a first threshold, and a second diffraction efficiency of each out-coupling diffractive structure is no greater than a second threshold that is no greater than the first threshold.

First claim

The invention claimed is:

1. An optical device, comprising:
an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device, the light having a spectral bandwidth with a peak wavelength;
an in-coupling diffractive structure configured to diffract the light to propagate in the optical guiding device; and
a plurality of out-coupling diffractive structures arranged downstream the in-coupling diffractive structure along the first direction and configured to diffract at least part of the light out of the optical guiding device along a second direction different from the first direction,
wherein the plurality of out-coupling diffractive structures are configured to have gradually increased diffraction efficiencies for the light along the first direction away from the in-coupling diffractive structure, and
wherein a first diffraction efficiency of the in-coupling diffractive structure for light with the peak wavelength is no smaller than a first threshold, and a second diffraction efficiency of each of the plurality of out-coupling diffractive structures for the light with the peak wavelength is no greater than a second threshold, the first threshold being greater than the second threshold.

2. The optical device of claim 1 , wherein the first diffraction efficiency is no smaller than 60%, and the second diffraction efficiency is no greater than 20%.

3. The optical device of claim 1 , wherein the in-coupling diffractive structure comprises a first reflection grating, a first transmission grating, or a first transflection grating, and
wherein each of the plurality of out-coupling diffractive structures comprises a respective second reflection grating, a respective second transmission grating, or a respective second transflection grating.

4. The optical device of claim 1 , wherein the in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and each of the plurality of out-coupling diffractive structures is configured to cause a second optical dispersion for the light, and
wherein the first optical dispersion and the second optical dispersion are compensated with each other, such that light diffracted out of the optical guiding device has no or little optical dispersion.

5. The optical device of claim 1 , wherein the diffracted light from the in-coupling diffractive structure propagates via total internal reflection in the optical guiding device along the first direction to be sequentially incident on each of the plurality of out-coupling diffractive structures along the first direction, and wherein the plurality of out-coupling diffractive structures are configured such that diffracted light by each of the plurality of out-coupling diffractive structures out of the optical guiding device has a same optical power, and
wherein the diffracted light from the in-coupling diffractive structure is incident on each of the plurality of out-coupling diffractive structures with a same incident angle, and wherein each of the plurality of out-coupling diffractive structures is configured such that the diffracted light by each of the plurality of out-coupling diffractive structures has a same diffraction angle.

6. A system comprising:
a display; and
an optical device comprising:
an optical guiding device configured to guide light to propagate along a first direction within the optical guiding device, the light having a spectral bandwidth with a peak wavelength;
an in-coupling diffractive structure configured to diffract the light to propagate in the optical guiding device; and
a plurality of out-coupling diffractive structures arranged downstream the in-coupling diffractive structure along the first direction and configured to diffract at least part of the light out of the optical guiding device along a second direction that is different from the first direction,
wherein the plurality of out-coupling diffractive structures are configured to have gradually increased diffraction efficiencies for the light along the first direction away from the in-coupling diffractive structure, and
wherein a first diffraction efficiency of the in-coupling diffractive structure for light with the peak wavelength is no smaller than a first threshold, and a second diffraction efficiency of each of the plurality of out-coupling diffractive structures for the light with the peak wavelength is no greater than a second threshold, the first threshold being greater than the second threshold.

7. The system of claim 6 , wherein the first diffraction efficiency is no smaller than 60%, and the second diffraction efficiency is no greater than 20%.

8. The system of claim 6 , wherein the in-coupling diffractive structure is configured to cause a first optical dispersion for the light, and each of the plurality of out-coupling diffractive structures is configured to cause a second optical dispersion for the light, and
wherein the first optical dispersion and the second optical dispersion are compensated with each other, such that light diffracted out of the optical guiding device has no or little optical dispersion.

9. The system of claim 6 , wherein the diffracted light from the in-coupling diffractive structure propagates via total internal reflection in the optical guiding device along the first direction to be sequentially incident on each of the plurality of out-coupling diffractive structures along the first direction, and wherein the plurality of out-coupling diffractive structures are configured such that diffracted light by each of the plurality of out-coupling diffractive structures out of the optical guiding device has a same optical power, and
wherein the diffracted light from the in-coupling diffractive structure is incident on each of the plurality of out-coupling diffractive structures with a same incident angle, and wherein each of the plurality of out-coupling diffractive structures is configured such that the diffracted light by each of the plurality of out-coupling diffractive structures has a same diffraction angle.

10. The system of claim 6 , wherein the display comprises a plurality of display elements extending along the first direction and a third direction perpendicular to the first direction and the second direction,
wherein the optical guiding device is a first optical guiding device, the in-coupling diffractive structure is a first in-coupling diffractive structure, and the plurality of out-coupling diffractive structures is a plurality of first out-coupling diffractive structures, and
wherein the system further comprises:
a second optical guiding device extending along the first direction and the third direction,
a plurality of second in-coupling diffractive structures arranged in or on the second optical guiding device along the first direction, and
multiple groups of second out-coupling diffractive structures, each group of second out-coupling diffractive structures being arranged in or on the second optical guiding device along the third direction,

wherein, for each of the plurality of second in-coupling diffractive structures,
the second in-coupling diffractive structure is configured to receive first light diffracted from a respective first out-coupling diffractive structure and diffract the first light to propagate in the second optical guiding device via TIR along the third direction to be sequentially incident on a corresponding group of second out-coupling diffractive structures, and
each of the corresponding group of second out-coupling diffractive structures is configured to receive second light reflected from the second optical guiding device and diffract the second light out of the second optical guiding device

Assignees

• Pacific Light & Hologram Inc

Inventors

• Blackley Jonathan Seamus
• Bahr Richard
• Boyett Watson Brent
• Colin Sylvain Marcel
• Green Robin James
• Guasch Isaac Serrano
• Hart Stephen John
• Hess Robert Alan
• Hsu Margaret H
• Jutrzenka Christoph Von
• Kim Deagyu
• Loya Mark Anthony
• Macneill Kelly Swan
• Neil Benjamin Francis
• Qaderi Kamran
• Qin Tina
• Ramirez Jesus Manuel Caridad
• Sashidharan Jayakrishna
• Sefami Asher Zelig
• Smith Jeff
• Srinivasiah Robert David
• Walavalkar Sameer Sudhir
• Wiensch Joshua D
• Williamson Daniel Dereck

Classifications

• G02F1/13439

  characterised by their electrical, optical, physical properties; materials therefor; method of making · CPC title

• G09G3/36

  using liquid crystals · CPC title

• G09G3/3413

  Details of control of colour illumination sources · CPC title

• G02F1/134309

  characterised by their geometrical arrangement · CPC title

• G09G3/003 Primary

  to produce spatial visual effects · CPC title