Holographic and diffractive optical encoding systems

Patent metadata

Field	Value
Publication number	US-11092930-B2
Application number	US-201916635159-A
Country	US
Kind code	B2
Filing date	Jan 14, 2019
Priority date	Jan 14, 2018
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

Holographic and diffractive optical encoding techniques for forming reflection or transmission holograms. The encoding device includes a substrate having an interference pattern that can propagate light along a light propagation path from one side of the substrate to another side of the substrate. Furthermore, an optical element may be used to propagate light according to a four-dimensional light field coordinate system.

First claim

What is claimed is:

1. A waveguide comprising:
a substrate comprising a photographic medium; and
an interference pattern encoded in the photographic medium, the interference pattern defining an array of substrate sites in the substrate;
wherein the interference pattern is configured to propagate light along light propagation paths extending from light locations on a first side of the substrate toward a second side of the substrate;
wherein the light propagation paths comprise sets of light propagation paths that extend through a same substrate site and a same light location, wherein each set of light propagation paths are configured to extend in substantially a unique direction on the second side of the substrate and converge from the same substrate site to the same light location on the first side of the substrate, the unique direction being determined by an angular direction of a chief ray propagation path in each set of light propagation paths; and
whereby, the array of substrate sites is configured to propagate light according to a four-dimensional light field coordinate system comprising spatial coordinates defined by positions of the substrate sites and angular coordinates defined by the unique directions of the sets of light propagation paths for each substrate site.

2. The waveguide of claim 1 , wherein the photographic medium comprises at least one of the materials selected from the group consisting of photographic emulsions, dichromated gelatin, photoresists, photothermoplastics, photopolymer, and photorefractives.

3. The waveguide of claim 1 , wherein the interference pattern comprises holograms encoded to direct light as an array of lenslets, thereby forming a holographic lenslet array (“HLA”), and wherein the holograms comprise at least one of reflective holograms and transmissive holograms.

4. The waveguide of claim 3 , wherein the HLA comprises a plane subdivided into sites, and the substrate sites correspond to the sites of the HLA, and wherein the sites of the HLA are each configured to direct light as a lenslet.

5. A holographic energy directing system, the system comprising the waveguide of claim 1 and an illumination source array (“ISA”) configured to provide illumination at the light locations on the first side of the substrate.

6. The holographic energy directing system of claim 5 , wherein the ISA comprises a plurality of light sources at the light locations on the first side of the substrate.

7. The holographic energy directing system of claim 5 , wherein the ISA defines a plane subdivided into sites, and the sites of the ISA each correspond to at least one respective site of the HLA and each comprise a plurality of ISA subsite locations corresponding to the light locations on the first side of the substrate.

8. The holographic energy directing system of claim 7 , wherein the corresponding sites of the HLA and the ISA at least partially overlap, or have different dimensions, or are co-centered.

9. The holographic energy directing system of claim 7 , wherein the chief ray propagation path comprises the light propagation path between one of the ISA subsite locations and a center of the corresponding respective site of the HLA, and wherein the unique direction of each set of light propagation paths is determined by a chief ray angle (“CRA”) of the respective chief ray propagation path.

10. The holographic energy directing system of claim 9 , wherein, for each ISA subsite location of a first site of the ISA, a corresponding site of the HLA in the interference pattern is encoded with a common input reference beam angle determined by the CRA of the respective chief ray propagation path for each ISA subsite location.

11. The holographic energy directing system of claim 9 , wherein, for each ISA subsite location of a first site of the ISA, a corresponding site of the HLA in the interference pattern is encoded with output object beam angles determined by light propagation paths converging from HLA subsite locations in the corresponding site of the HLA to each ISA subsite location of the first site of the ISA.

12. The holographic energy directing system of claim 9 , wherein, for each ISA subsite location of a first site of the ISA, a corresponding site of the HLA in the interference pattern is encoded with a common input reference beam angle determined by the CRA of the respective chief ray propagation path for each ISA subsite location and with output object beam angles determined by light propagation paths converging from HLA subsite locations in the corresponding site of the HLA to each ISA subsite location of the first site of the ISA.

13. The holographic energy directing system of claim 12 , wherein, for the first site of the ISA and the corresponding site of the HLA, one of the respective HLA subsite locations is encoded at one time with the common input reference beam angle for a single respective ISA subsite location and one of the output object beam angles for the single respective ISA subsite location.

14. The holographic energy directing system of claim 12 , wherein, for the first site of the ISA and the corresponding site of the HLA, a plurality of the respective HLA subsite locations are encoded at the same time with the common input reference beam angle for a single respective ISA subsite location and the respective plurality of the output object beam angles for the single respective ISA subsite location.

15. The holographic energy directing system of claim 12 , wherein, for the first site of the ISA and the corresponding site of the HLA, one of the respective HLA subsite locations is encoded at one time with a plurality of common input reference beam angles for a respective plurality of ISA subsite locations and the respective plurality of the output object beam angles for the respective plurality of ISA subsite locations.

16. An array of waveguides comprising:
a substrate comprising a photographic medium;
an interference pattern encoded in the photographic medium, the interference pattern defining an array of substrate sites in the substrate, each substrate site comprising a plurality of substrate subsites; and
an optical element, the optical element defining an array of optical element sites each corresponding to a respective substrate site, each optical element site comprising a plurality of optical element subsite locations;
wherein the interference pattern is configured to propagate light along light propagation paths extending through the substrate subsites of each substrate site to the optical element subsite locations of the respective optical element site, wherein the light propagation paths comprise sets of light propagation paths that extend through a same optical element site and a same substrate subsite of a corresponding substrate site;
wherein each set of light propagation paths extend from the optical element away from substrate in substantially a unique direction and converge from different optical element subsite locations of the same optical element site to the same substrate subsite of the corresponding substrate site, the unique direction being determined by an angular direction of a chief ray propagation path in each set of light propagation paths; and
whereby, the array of optical element sites is configured to propagate light according to a four-dimensional light field coordinate system comprising spatial coordinates defined by positions of the optical sites and angular coordinates defined by the unique directions of the sets of light propagation paths for each optical site.

17. The array of waveguides of claim 16 , wherein the p

Assignees

• Light Field Lab Inc

Inventors

• Karafin Jonathan Sean
• Bevensee Brendan Elwood

Classifications

• G03H2223/16

  Optical waveguide, e.g. optical fibre, rod · CPC title

• G03H2223/23

  Diffractive element · CPC title

• G03H2222/34

  Multiple light sources · CPC title

• G03H2223/14

  Diffuser, e.g. lens array, random phase mask · CPC title

• G03H2001/2228

  adapted for reflection and transmission reconstruction · CPC title