Method and apparatus for light field generation

Patent metadata

Field	Value
Publication number	US-10599098-B2
Application number	US-201815876719-A
Country	US
Kind code	B2
Filing date	Jan 22, 2018
Priority date	Jan 26, 2017
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A nanophotonic phased array is configured to generate dynamic three-dimensional imagery when employed as an oscillatory beam-steering device. A scanning nanophotonic phased array generates programmable light fields. That is, a phased array generates reconfigurable light fields when controlled to perform an angular scan of incident illumination synchronized with respect to modulation of the incident illumination.

First claim

What is claimed is:

1. A radiation projector comprising:
a plurality of nanophotonic antennas configured to emit electromagnetic radiation;
a plurality of phase delay elements, each phase delay element characterized by a phase delay, at least one phase delay element associated with at least one of the plurality of nanophotonic antennas; and
a control signal generator configured to generate a control signal associated with the plurality of delay elements,
wherein the control signal generator is further configured to recurrently update phase delays of the plurality of phase delay elements in such a manner as to cause the electromagnetic radiation to substantially span at least one contiguous solid angle.

2. A radiation projector according to claim 1 wherein an output of the plurality of nanophotonic antennas generates a three dimensional light field of imagery.

3. A radiation projector according to claim 1 further comprising:
a modulator for receiving data representative of a three dimensional scene scanned in several different directions and producing a plurality of time-varying illumination patterns.

4. A radiation projector according to claim 3 wherein the electromagnetic radiation emitted by the antennas is visible light.

5. A radiation projector according to claim 3 wherein the plurality of nanophotonic antennas is coupled to the modulator for dividing the time-varying illumination patterns into a plurality of paths, wherein a path is associated with each antenna within the array.

6. A radiation projector according to claim 5 wherein the plurality of delay elements are a plurality of phase shifters each associated with an antenna for shifting the phase of the time-varying illumination patterns collectively so that the patterns are modulated in synchrony for each of several directions.

7. A radiation projector according to claim 1 , wherein the phase delay elements shift the phase in a single direction.

8. A radiation projector according to claim 1 , wherein the phase delay elements shift the phase in both a horizontal and a vertical direction.

9. A radiation projector according to claim 1 further comprising:
a controller for providing phase shift control signals to each of the phase delay elements to provide a sequence of video images.

10. A radiation projector according to claim 1 , wherein the phase delay elements are phase shifters and the phase shifters are associated with an array of nanophotonic antennas that represent a single pixel and the phase shifters for the single pixel receive a phase control signal in the x direction and in the y direction.

11. A radiation projector according to claim 1 , wherein only two phase shift control values are needed to steer a radiation pattern from an antenna.

12. A radiation projector according to claim 1 wherein the plurality of nanophotonic antennas are divided into a plurality of arrays and each array represents a single pixel.

13. A radiation projector according to claim 1 wherein the plurality of nanophotonic antennas are divided into a plurality of arrays and each array represents a single hogel.

14. A radiation projector according to claim 1 wherein the plurality of nanophotonic antennas are divided into a plurality of arrays and each array represents a single wafel.

15. A radiation projector according to claim 1 wherein the plurality of phase delay elements is a MEMS phase shifter that mechanically alters phase based upon movement of a phase actuator.

16. A radiation projector according to claim 15 wherein the phase actuator is a membrane.

17. A radiation projector according to claim 1 further comprising:
a database containing the data representative of the three dimensional scene scanned from several different directions.

18. A radiation projector according to claim 1 wherein the emitted output radiation can be directed to converge at a spatial region, such that a viewer can view the emitted output radiation if the viewer is within the spatial region and the viewer cannot view the emitted output radiation if the viewer is outside of the spatial region.

19. A radiation projector according to claim 18 wherein the nanophotonic antennas are controlled with a second control signal to steer the emitted output radiation in a second direction.

20. A radiation projector according to claim 1 , wherein the nanophotonic antennas are controlled with a first control signal to steer the emitted output radiation in a first direction.

21. A radiation projector according to claim 1 , wherein the plurality of nanophotonic antennas are arranged in an array and the array is arranged on a two dimensional surface.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Favalora Gregg E
• Spector Steven J
• Lane Benjamin F

Classifications

• H04N13/305

  using lenticular lenses, e.g. arrangements of cylindrical lenses · CPC title

• G03H1/0443 Primary

  Digital holography, i.e. recording holograms with digital recording means (holobject computation G03H1/0866) · CPC title

• G02F1/2955

  by controlled diffraction or phased-array beam steering (controlled diffraction for optical waveguide switching G02F1/313) · CPC title

• G03H2001/0088

  for video-holography, i.e. integrating hologram acquisition, transmission and display · CPC title

• H04N13/32 Primary

  using arrays of controllable light sources; using moving apertures or moving light sources · CPC title