Free-space optical communication system with optical phased array telescope

Abstract

This invention provides improved systems and methods for optical communication with reduced size, weight, and power consumption. [Solution] A method for use between satellites or other distant systems undergoing large relative motion, comprising using a diamagnetically levitating magnetic actuator or other actuator to orient an optical phased array (OPA) to a distant target system by controlling the orientation of the OPA. The OPA has reduced size and mass compared to conventional telescopes, providing an equivalent beam aperture while reducing the size, weight, and cost of the OPA and associated actuators. The actuators allow the OPA to omit or have fewer phase shifter elements than previous steerable OPA telescopes, reducing complexity, cost, and power requirements.

Claims

1. It is a system, An optical phased array comprising a first optical expanding element having at least two emitter diffraction gratings and a beam splitter, wherein the at least two emitter diffraction gratings are configured to receive corresponding portions of an input optical beam via the beam splitter and emit corresponding portions of a composite output optical beam of the optical phased array, the input optical beam having a first aperture smaller than the second aperture of the composite output optical beam, and the relative phase between the light emitted from each of the at least two emitter diffraction gratings is static. A steering actuator is mechanically coupled to the optical phased array and configured to adjust the orientation of the optical phased array, A system that includes these features.

2. A system according to claim 1, wherein the steering actuator comprises a magnetic bearing, the magnetic bearing comprising a plurality of magnets and a layer of diamagnetic material configured to repel the plurality of magnets.

3. A system according to claim 1, wherein the optical phased array comprises a plurality of optical magnifying elements, including the first optical magnifying element, and each of the plurality of optical magnifying elements receives a corresponding portion of the input optical beam and emits a corresponding portion of the composite output optical beam.

4. A system according to claim 3, further comprising a fixed phase plate, wherein the fixed phase plate provides static phase adjustment to the light emitted from each of the plurality of optical magnifying elements.

5. The system according to claim 3, further, A plurality of phase shifters, each of which is operable to adjust the phase of light emitted from each corresponding optical expanding element among the plurality of optical expanding elements with respect to the phase of the input optical beam, A controller configured to perform controller operations, wherein the controller operations are A system comprising operating the plurality of phase shifters to control the direction of the composite output light beam relative to the optical phased array.

6. The system according to claim 5, further, An optical emitter configured to generate the input optical beam received by the optical phased array, A photodetector optically coupled to the optical phased array so as to receive light received by the optical phased array from the direction of the composite output light beam via the plurality of optical magnifying elements, Equipped with, The aforementioned controller operation further includes: The steering actuator is operated to orient the optical phased array toward the target, During the first period, the plurality of phase shifters are operated to control the direction of the composite output light beam in the first direction relative to the optical phased array. During the first period, the optical emitter is operated to generate a beam of light that encodes the first information, thereby optically transmitting the first information to the target. During the second period, the plurality of phase shifters are operated to control the direction of the composite output light beam to a second direction relative to the optical phased array, wherein the second direction differs from the first direction. A system comprising operating the photodetector to detect second information optically transmitted from the target and received via the optical phased array during the second period.

7. A system according to claim 1, further comprising an optical emitter, wherein the optical emitter is coupled to the optical phased array via a flexible optical fiber.

8. The system according to claim 1, wherein the input light beam includes light having a wavelength between 380 nanometers and 2400 nanometers.

9. The system according to claim 1, wherein the first optical expanding element comprises a first region and a second region, each of the at least two emitter diffraction gratings is associated with a tapered optical waveguide to which each emitter diffraction grating receives a corresponding portion of the input optical beam from the beam splitter, the at least two emitter diffraction gratings are located within the first region, the tapered optical waveguide and the beam splitter are located within the second region, and the ratio of the area of ​​the first region to the area of ​​the second region is greater than 19:

1.

10. The system according to claim 1, wherein the second aperture of the composite output light beam is greater than 5 centimeters.

11. The system according to claim 1, wherein the system is an artificial satellite system, and the system further comprises An optical emitter configured to generate the input optical beam received by the optical phased array, A controller configured to perform controller operations, wherein the controller operations are The steering actuator is operated to orient the optical phased array toward the target, A system comprising operating the optical emitter to generate a beam of light that encodes first information, thereby optically transmitting the first information to the target.

12. The system according to claim 1, further, Equipped with a photodetector, The photodetector is optically coupled to the optical phased array so as to receive light received by the optical phased array from the direction of the output light beam via the plurality of optical magnifying elements, and the photodetector is an avalanche photodiode in this system.

13. It is a method, A steering actuator is operated to orient the optical phased array toward a target, and the steering actuator is mechanically coupled to the optical phased array and configured to adjust the orientation of the optical phased array. During the first period, multiple phase shifters of the optical phased array are operated to control the direction of the output light beam of the optical phased array in a first direction relative to the optical phased array. During the first period, the first information is optically transmitted to the target, The optical emitter is operated to generate a beam of light that encodes the first information, The optical phased array is oriented toward the target, and the beam of light generated by the optical emitter is received by the optical phased array as an input light beam. During the second period, the plurality of phase shifters are operated to control the direction of the output light beam to a second direction relative to the optical phased array, wherein the second direction differs from the first direction. The system includes optically receiving second information from the target during the second period, and optically receiving the second information from the target during the second period is A method comprising operating a photodetector optically coupled to the optical phased array to detect the second information optically transmitted from the target and received via the optical phased array.

14. A method according to claim 13, wherein the steering actuator comprises a magnetic bearing and a plurality of coils, the magnetic bearing comprising a plurality of magnets and a layer of diamagnetic material configured to repel the plurality of magnets, and the steering actuator being operated to orient the optical phased array toward the target comprises adjusting the orientation of the optical phased array by controlling the current supplied to the plurality of coils to apply force to the plurality of magnets.

15. A method according to claim 13, wherein the photodetector is an avalanche photodiode.

16. A method according to claim 13, wherein the output light beam has an aperture greater than 5 centimeters.

17. A method according to claim 13, wherein the optical phased array comprises a first optical expanding element having at least two emitter diffraction gratings and a beam splitter, wherein the at least two emitter diffraction gratings are configured to receive corresponding portions of an input optical beam via the beam splitter and emit corresponding portions of a composite output optical beam of the optical phased array, the input optical beam having a first aperture smaller than a second aperture of the composite output optical beam, and the relative phase between the light emitted from each of the at least two emitter diffraction gratings is static.

18. A method according to claim 13, wherein the beam of light encoding the first information includes light having a wavelength between 380 nanometers and 2400 nanometers.

19. A product comprising a computer-readable medium, wherein the computer-readable medium stores program instructions that, when executed by a computer device, cause the computer device to perform an action to affect the method of any one of claims 13 to 18.

20. It is a system, A phased optical array configured to receive an input optical beam and emit an output optical beam, wherein the input optical beam has a first aperture smaller than the second aperture of the output optical beam. A system comprising: a steering actuator coupled to the optical phased array and configured to adjust the orientation of the optical phased array, wherein the steering actuator comprises a magnetic bearing, the magnetic bearing comprising a plurality of magnets and a layer of diamagnetic material configured to repel the plurality of magnets.

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