Holographic and diffractive optical encoding systems

Patent metadata

Field	Value
Publication number	US-2022035311-A1
Application number	US-202117375609-A
Country	US
Kind code	A1
Filing date	Jul 14, 2021
Priority date	Jan 14, 2018
Publication date	Feb 3, 2022
Grant date	—

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

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; 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 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”).

4 . The waveguide of claim 3 , wherein the holograms comprise reflective holograms.

5 . The waveguide of claim 3 , wherein the holograms comprises transmissive holograms.

6 . 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.

7 . The waveguide of claim 6 , wherein the sites of the HLA are each configured to direct light as a lenslet.

8 . 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.

9 . The holographic energy directing system of claim 8 , wherein the ISA comprises a plurality of light sources at the light locations on the first side of the substrate.

10 . The holographic energy directing system of claim 8 , wherein the ISA defines a plane subdivided into sites, and the sites of the ISA each corresponding to at least one respective site of the HLA and each comprising a plurality of ISA subsite locations corresponding to the light locations on the first side of the substrate.

11 . The holographic energy directing system of claim 10 , wherein the corresponding sites of the HLA and the ISA at least partially overlap.

12 . The holographic energy directing system of claim 10 , wherein the corresponding sites of the HLA and the ISA have different dimensions.

13 . The holographic energy directing system of claim 10 , wherein the corresponding sites of the HLA and the ISA are co-centered.

14 . The holographic energy directing system of claim 10 , 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.

15 . The holographic energy directing system of claim 14 , 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.

16 . The holographic energy directing system of claim 15 , 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.

17 . The holographic energy directing system of claim 15 , 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.

18 . The holographic energy directing system of claim 15 , 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.

19 . The holographic energy directing system of claim 1815 , 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.

20 . The holographic energy directing system of claim 1815 , 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.

21 .- 36 . (canceled)

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