Light field generator devices with series output couplers

Patent metadata

Field	Value
Publication number	US-10416468-B2
Application number	US-201815938700-A
Country	US
Kind code	B2
Filing date	Mar 28, 2018
Priority date	Mar 28, 2017
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

Electro-holographic light field generator devices comprising surface acoustic wave (SAW) optical modulators are disclosed that employ multiple output couplers. These output couplers might be distributed along waveguides of the SAW modulators, within output coupling regions. Each of these output couplers can be configured for directing an incident leaky mode light at different output angles. In some cases, it may be desirable to employ the output couplers to function as different sub-pixels, to provide light to different viewing directions. The output couplers may be mirrors, volume gratings, chirped gratings, reflection gratings, two dimensional gratings, and/or transmission gratings. The output couplers may be angled so that the coupling output fans for each optical modulator are offset from the waveguide for that optical modulator.

First claim

What is claimed is:

1. A light field generator device, comprising:
a device substrate;
an array of waveguides formed in the substrate;
one or more surface acoustic wave (SAW) transducers for generating a SAW in the substrate;
a set of output couplers for each of the waveguides for directing diffracted light from the waveguide at different output angles with respect to each other.

2. The light field generator device as claimed in claim 1 , further comprising multiple sets of output couplers for each of the waveguides.

3. The light field generator device as claimed in claim 1 , wherein the set of output couplers comprises at least three output couplers at different angles with respect to the waveguide.

4. The light field generator device as claimed in claim 1 , wherein each of the waveguides has a separate SAW transducer.

5. The light field generator device as claimed in claim 1 , wherein the SAW transducers are shared among adjacent waveguides.

6. The light field generator device as claimed in claim 1 , wherein the output couplers comprise volume gratings formed in the substrate.

7. The light field generator device as claimed in claim 1 , wherein the substrate comprises a SAW substrate bonded to a transparent substrate and the output couplers are gratings formed in the transparent substrate.

8. The light field generator device as claimed in claim 1 , wherein the output couplers comprise gratings bonded to a distal side of the substrate.

9. The light field generator device as claimed in claim 1 , wherein the output couplers comprise gratings bonded to or formed on side walls of trenches formed in a distal side of the substrate.

10. The light field generator device as claimed in claim 1 , wherein the output couplers are rotated with respect to the waveguide to provide horizontal and/or vertical parallax.

11. The light field generator device as claimed in claim 1 , wherein the output couplers are reflective gratings.

12. The light field generator device as claimed in claim 1 , wherein the output couplers are transmissive gratings.

13. The light field generator device as claimed in claim 1 , wherein the output couplers function as different sub-pixels, to provide light to different viewing directions.

14. The light field generator device as claimed in claim 1 , wherein the output couplers function to increase the angular fan of the exit light.

15. A 3D display system comprising one or more a light field generator devices, wherein each of the devices comprises:
a device substrate;
an array of waveguides formed in the substrate;
one or more surface acoustic wave (SAW) transducers for generating a SAW in the substrate; and
a set of output couplers for each of the waveguides for directing diffracted light from the respective waveguide at different output angles with respect to each other.

16. A method for generating a light field, comprising:
diffracting light out of waveguides with surface acoustic waves (SAWs) formed in a substrate;
directing the diffracted light with different output couplers arranged along the length of the waveguides and at different angles with respect to each other.

17. The method as claimed in claim 16 , wherein multiple sets of output couplers are provided for each of the waveguides.

18. The method as claimed in claim 16 , wherein the set of output couplers comprises at least three output couplers at different angles with respect to the waveguide.

19. The method as claimed in claim 16 , further comprising generating the SAWs with separate SAW transducers.

20. The method as claimed in claim 16 , further comprising generating the SAWs with shared transducers.

21. The method as claimed in claim 16 , wherein the output couplers comprise volume gratings formed in the substrate.

22. The method as claimed in claim 16 , wherein the substrate comprises a SAW substrate bonded to a transparent substrate and the output couplers are gratings formed in the transparent substrate.

23. The method as claimed in claim 16 , wherein the output couplers comprise gratings bonded to a distal side of the substrate.

24. The method as claimed in claim 16 , wherein the output couplers comprise gratings bonded to or formed on side walls of trenches formed in a distal side of the substrate.

25. The method as claimed in claim 16 , further comprising rotating the output couplers with respect to the waveguide to provide horizontal and/or vertical parallax.

26. The method as claimed in claim 16 , wherein the output couplers are reflective gratings.

27. The method as claimed in claim 16 , wherein the output couplers are transmissive gratings.

28. The method as claimed in claim 16 , further comprising the output couplers functioning as different sub-pixels, to provide light to different viewing directions.

29. The method as claimed in claim 16 , further comprising the output couplers functioning to increase the angular fan of the exit light.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

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

Classifications

• H04N13/302

  for viewing without the aid of special glasses, i.e. using autostereoscopic displays · CPC title

• H03H9/02968

  with optical devices (mounting in enclosures H03H9/12) · CPC title

• G03H2225/55

  Having optical element registered to each pixel · CPC title

• G03H2225/33

  Complex modulation · CPC title

• G03H2225/23

  Grating based SLM · CPC title