System and method for diffractive steering of electromagnetic radiation

Patent metadata

Field	Value
Publication number	US-10935868-B2
Application number	US-201816140714-A
Country	US
Kind code	B2
Filing date	Sep 25, 2018
Priority date	Sep 28, 2017
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

A light steeling system and method for diffractive steering of electromagnetic radiation such as visible light is disclosed. Embodiments of the light steering system include leaky-mode SAW modulators as light modulator devices. The SAW modulators preferably include reflective diffractive gratings. The gratings are mounted to/patterned upon an exit face that opposes an exit surface of the SAW modulator, in one example. Steering of light signals emitted from the SAW modulators in these systems can be accomplished by varying wavelength of light signals introduced to the SAW modulators, and/or by varying frequency of RF drive signals applied to the SAW modulators. In addition, light field generators that incorporate SAW modulators of the proposed light steering system within displays of the light field generators are also disclosed.

First claim

What is claimed is:

1. A light steering system, comprising:
a diffractive modulator that steers light using diffraction;
a multiwavelength light source that generates light at different wavelengths for input into the diffractive modulator;
a controller for controlling a wavelength of light generated by the multiwavelength light source to control an angle of light emitted from the diffractive modulator; and
a radio frequency signal generator for providing radio frequency drive signals to the modulator, wherein the radio frequency signal generator is controlled by the controller.

2. A system as claimed in claim 1 , wherein the diffractive modulator is an acoustic optic modulator.

3. A system as claimed in claim 1 , wherein the diffractive modulator is a surface acoustic wave (SAW) modulator.

4. A system as claimed in claim 1 , wherein the multiwavelength light source generates light that is tunable over a wavelength range of greater than 5 nanometers by the controller to control an angle of light emitted from the diffractive modulator.

5. A system as claimed in claim 1 , further comprising a grating for increasing a steered angle of the light from the diffractive modulator.

6. A system as claimed in claim 1 , wherein the controller modulates a wavelength of the light from the multiwavelength light source to provide a coarse change in angular extent of the light emitted by the diffractive modulator, and the controller frequency modulates of the RF drive signals generated by the radio frequency signal generator applied to the modulator to provide a fine change in the angular extent of the light emitted by the modulator.

7. A system as claimed in claim 1 , wherein the diffractive modulator comprises a substrate and a transducer, being driven by the radio frequency drive signals, for the substrate for generating a surface acoustic wave that diffracts light in the diffractive modulator.

8. A system as claimed in claim 7 , wherein the surface acoustic wave diffracts the light to propagate toward a distal face of the substrate and the light is redirected to exit out a proximal face of the substrate.

9. A system as claimed in claim 8 , wherein the light is redirected by a grating.

10. A system as claimed in claim 8 , wherein the light is redirected by a reflective diffractive grating.

11. A system as claimed in claim 8 , wherein the light, after exiting out of the proximal face, is further conditioned by an optical element.

12. A system as claimed in claim 11 , wherein the optical element is a diffractive lens.

13. A system as claimed in claim 11 , wherein the optical element is a refractive lens.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Byrnes Steven J
• Favalora Gregg E
• Frank Ian Ward
• Kopa Anthony
• Korn Jeffrey A
• Moebius Michael G

Classifications

• G03H1/2294

  Addressing the hologram to an active spatial light modulator · CPC title

• G02F1/335 Primary

  having an optical waveguide structure · CPC title

• G02F2203/22

  diffractive · CPC title

• G02F2203/24

  beam steering · CPC title

• G02B6/356

  in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links (switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001) · CPC title