SAW modulators and light steering methods

Patent metadata

Field	Value
Publication number	US-11340513-B2
Application number	US-202017062960-A
Country	US
Kind code	B2
Filing date	Oct 5, 2020
Priority date	Jan 30, 2017
Publication date	May 24, 2022
Grant date	May 24, 2022

Abstract

An electro-holographic light field generator device is disclosed. The light field generator device has an optical substrate with a waveguide face and an exit face. One or more surface acoustic wave (SAW) optical modulator devices are included within each light field generator device. The SAW devices each include a light input, a waveguide, and a SAW transducer, all configured for guided mode confinement of input light within the waveguide. A leaky mode deflection of a portion of the waveguided light, or diffractive light, impinges upon the exit face. Multiple output optics at the exit face are configured for developing from each of the output optics a radiated exit light from the diffracted light for at least one of the waveguides. An RF controller is configured to control the SAW devices to develop the radiated exit light as a three-dimensional output light field with horizontal parallax and compatible with observer vertical motion.

First claim

What is claimed is:

1. An electro-holographic light field generator device, comprising:
a substrate;
an array of surface acoustic wave modulators having waveguides extending across the substrate; and
two dimensional array of diffractive optics for shaping output light from the substrate;
wherein the array of optics is an array of diffractive lenses.

2. The device as claimed in claim 1 , wherein the waveguides extend parallel to each other across the substrate.

3. The device as claimed in claim 1 , wherein a separation between the waveguides is less than 400 μm.

4. The device as claimed in claim 1 , wherein a length of the waveguides is less than 10 centimeters.

5. The device as claimed in claim 1 , wherein different ones of the waveguides carry different colors of light.

6. The device as claimed in claim 1 , wherein the array of optics is on an exit face of the substrate.

7. The device as claimed in claim 1 , wherein the diffractive lenses are arranged into lens strips, one strip for each waveguide.

8. The device as claimed in claim 7 , wherein a length of each of the diffractive lenses is less than 2 millimeters.

9. The device as claimed in claim 1 , wherein the two dimensional array of diffractive optics is formed on a distal face of the substrate.

10. The device as claimed in claim 1 , wherein the two dimensional array of diffractive optics increases an exit angle fan of the light from the substrate.

11. The device as claimed in claim 1 , wherein the array of surface acoustic wave modulators includes multiple SAW transducers.

12. The device as claimed in claim 1 , wherein each of the optics of the array has a length of 100 μm-2 mm.

13. The device as claimed in claim 1 , wherein the substrate includes at least three surface acoustic wave modulators.

14. The device as claimed in claim 1 , wherein the substrate includes twelve surface acoustic wave modulators.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Frank Ian W
• Byrnes Steven J
• Laine Juha-Pekka J
• Favalora Gregg E
• Register Joseph J
• Callahan Dennis M
• Moebius Michael G

Classifications

• G02F2203/28

  focussing or defocussing · CPC title

• G03H2225/36

  Polarisation · CPC title

• G02F2201/305

  diffraction grating · CPC title

• G02F1/11

  based on acousto-optical elements, e.g. using variable diffraction by sound or like mechanical waves (acousto-optical deflection G02F1/33) · CPC title

• G02F2203/07

  Polarisation dependent · CPC title