Systems, devices, and methods for angle- and wavelength-multiplexed holographic optical elements

Patent metadata

Field	Value
Publication number	US-10133075-B2
Application number	US-201615145609-A
Country	US
Kind code	B2
Filing date	May 3, 2016
Priority date	May 4, 2015
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

Systems, devices, and methods for combined angle- and wavelength multiplexing in holographic optical elements (“HOE”) are described. An angle- and wavelength-multiplexed HOE includes multiple angle-multiplexed sets of wavelength-multiplexed holograms. Each set of wavelength-multiplexed holograms includes at least two holograms that are each responsive to a different wavelength of light. Each angle-multiplexed set of wavelength-multiplexed holograms includes a respective set of wavelength-multiplexed holograms that are all responsive to light that is incident thereon with and angle of incidence that is within a particular range. An example application is described in which an angle- and wavelength-multiplexed HOE is used as a holographic combiner in a wearable heads-up display, where angle-multiplexing provides multiple spatially-separated exit pupils in the eyebox of the display and wavelength-multiplexing provides multiple colors to each respective exit pupil.

First claim

The invention claimed is:

1. An angle- and wavelength-multiplexed holographic optical element (“HOE”) comprising:
at least one layer of holographic material that includes:
a first set of wavelength-multiplexed holograms, wherein each respective hologram in the first set of wavelength-multiplexed holograms is responsive to light of a respective wavelength and unresponsive to light of other wavelengths, wherein all of the holograms in the first set of wavelength-multiplexed holograms are responsive to light that is incident thereon with an angle of incidence that is within a first range of angles of incidence and unresponsive to light that is incident thereon with an angle of incidence that is outside of the first range of angles of incidence, wherein the first set of wavelength-multiplexed holograms includes a first hologram that is responsive to light of a first wavelength and unresponsive to light of other wavelengths and a second hologram that is responsive to light of a second wavelength and unresponsive to light of other wavelengths, the second wavelength different from the first wavelength, wherein the first set of wavelength-multiplexed holograms directs a first set of light signals to a first location, and wherein each respective hologram in the first set of wavelength-multiplexed holograms converges light of a respective wavelength to a same first focus; and
a second set of wavelength-multiplexed holograms, wherein each respective hologram in the second set of wavelength-multiplexed holograms is responsive to light of a respective wavelength and unresponsive to light of other wavelengths, wherein all of the holograms in the second set of wavelength-multiplexed holograms are responsive to light that is incident thereon with an angle of incidence that is within a second range of angles of incidence and unresponsive to light that is incident thereon with an angle of incidence that is outside of the second range of angles of incidence, the second range of angles of incidence different from and non-overlapping with the first range of angles of incidence, wherein the second set of wavelength-multiplexed holograms includes a first hologram that is responsive to light of the first wavelength and unresponsive to light of other wavelengths and a second hologram that is responsive to light of the second wavelength and unresponsive to light of other wavelengths, and wherein the second set of wavelength-multiplexed holograms directs a second set of light signals to a second distinct location, wherein the second set of light signals is discrete from the first set of light signals, wherein the first set of wavelength-multiplexed holograms is unresponsive to the second set of light signals and the second set of light signals passes through at least one hologram of the first set of wavelength-multiplexed holograms before incidence on the second set of wavelength-multiplexed holograms, and wherein each respective hologram in the second set of wavelength-multiplexed holograms converges light of a respective wavelength to a same second focus, the second focus spatially separated from the first focus.

2. The angle- and wavelength-multiplexed HOE of claim 1 wherein:
the first set of wavelength-multiplexed holograms includes a third hologram that is responsive to light of a third wavelength and unresponsive to light of other wavelengths, the third wavelength different from both the first wavelength and the second wavelength; and
the second set of wavelength-multiplexed holograms includes a third hologram that is responsive to light of the third wavelength and unresponsive to light of other wavelengths.

3. The angle- and wavelength-multiplexed HOE of claim 1 wherein:
each respective hologram in the first set of wavelength-multiplexed holograms applies a same first optical function to light of a respective wavelength; and
each respective hologram in the second set of wavelength-multiplexed holograms applies a same second optical function to light of a respective wavelength, the second optical function different from the first optical function.

4. The angle- and wavelength-multiplexed HOE of claim 3 wherein both the first optical function and the second optical function include a reflection function.

5. The angle- and wavelength-multiplexed HOE of claim 1 wherein at least one layer of holographic material includes a holographic material selected from a group consisting of: a holographic film, a silver halide compound, and a photopolymer.

6. The angle- and wavelength-multiplexed HOE of claim 1 wherein the at least one layer of holographic material includes a first layer of holographic material and both the first set of wavelength-multiplexed holograms and the second set of wavelength-multiplexed holograms are included in the first layer of holographic material.

7. The angle- and wavelength-multiplexed HOE of claim 1 wherein the at least one layer of holographic material includes a first layer of holographic material that includes the first set of wavelength-multiplexed holograms and a second layer of holographic material that includes the second set of wavelength-multiplexed holograms, the second layer of holographic material carried by the first layer of holographic material.

8. The angle- and wavelength-multiplexed HOE of claim 1 wherein the at least one layer of holographic material includes a stack of layers of holographic material comprising:
a first set of layers of holographic material, wherein each layer of holographic material in the first set of layers of holographic material includes a respective one of the wavelength-multiplexed holograms in the first set of wavelength-multiplexed holograms; and
a second set of layers of holographic material, wherein each layer of holographic material in the second set of layers of holographic material includes a respective one of the wavelength-multiplexed holograms in the second set of wavelength-multiplexed holograms.

9. The angle- and wavelength-multiplexed HOE of claim 1 , further comprising:
at least one additional set of wavelength-multiplexed holograms, wherein for each additional set of wavelength-multiplexed holograms:
each respective wavelength-multiplexed hologram in the set of wavelength-multiplexed holograms is responsive to light of a respective wavelength and unresponsive to light of other wavelengths; and
all of the wavelength-multiplexed holograms in the set of wavelength-multiplexed holograms are responsive to light that is incident thereon with an angle of incidence that is within a particular range of angles of incidence and unresponsive to light that is incident thereon with an angle of incidence that is outside of the particular range of angles of incidence, and
wherein each additional set of wavelength-multiplexed holograms is responsive to light that is incident thereon with an angle of incidence that is within a respective range of angles of incidence and unresponsive to light that is incident thereon with an angle of incidence that is outside of the respective range of angles of incidence.

10. A wearable heads-up display (“WHUD”) comprising:
a support structure that in use is worn on a head of a user;
a scanning laser projector carried by the support structure; and
an angle- and wavelength-multiplexed holographic combiner carried by the support structure, wherein the angle- and wavelength-multiplexed holographic combiner is positioned within a field of view of an eye of the user when the support structure is worn on the head of the user, and wherein the angle- and wavelength-multiplexed holographic combiner comprises at least one layer of holographic material, the at least one layer of holographic material including:
a first set of wavelength-multiplexe

Assignees

• Thalmic Labs Inc

Inventors

• Bailey Matthew
• Alexander Stefan
• Morrison Vance R
• Mahon Thomas
• Holland Lloyd Frederick
• Choi Jaehong

Classifications

• G03H1/2286

  Particular reconstruction light (G03H1/24 takes precedence); Beam properties · CPC title

• G02B5/32

  Holograms used as optical elements · CPC title

• G02B2027/0123

  comprising devices increasing the field of view · CPC title

• G02B27/017

  Head mounted · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title