Mitigating cross-coupling in optical communications system

1. A system comprising:

a first communications terminal comprising:

an optical phased array (OPA) including a plurality of phase shifters configured to receive an optical communications beam from a second communications terminal; and

one or more processors configured to:

determine a link axis for communication with the second communications terminal based on the received optical communications beam;

identify a compensatory wavefront curvature for mitigating cross-coupling; and

generate a wavefront of an outgoing optical communications beam using the plurality of phase shifters based on the determined link axis and the compensatory wavefront curvature.

2. The system of claim 1 , further comprising the second communications terminal.

3. The system of claim 1 , wherein the one or more processors are further configured to identify the compensatory wavefront curvature by determining the compensatory wavefront curvature based on a distance between the first communications terminal and the second communications terminal, a wavelength of the wavefront, and an aperture sizes of the first communications terminal or the second communications terminal.

4. The system of claim 3 , wherein the one or more processors are further configured to:

determine an updated distance between the first communications terminal and the second communications terminal; and

adjust the compensatory wavefront curvature based on the updated distance.

5. The system of claim 4 , wherein the updated distance is determined based on timing information received by the first communications terminal from the second communications terminal.

6. The system of claim 1 , wherein the generated wavefront has a beam waist midway between the first communications terminal and the second communications terminal.

7. The system of claim 1 , wherein a radius of curvature of the generated wavefront when received at the second communications terminal is equal to a distance between the first communications terminal and the second communications terminal.

8. A method comprising for generating an outgoing communications beam at a first communications terminal, the method comprising:

determining, by one or more processors, a link axis for communication with a second communications terminal based on a received optical communications beam;

identifying, by the one or more processors, a compensatory wavefront curvature for mitigating cross-coupling; and

generating, by the one or more processors, a wavefront of an outgoing optical communications beam using a plurality of phase shifters of an optical phased array (OPA) architecture based on the determined link axis and the compensatory wavefront curvature.

9. The method of claim 8 , further comprising transmitting the outgoing optical communications beam to the second communications terminal.

10. The method of claim 8 , wherein identifying the compensatory wavefront curvature includes determining the compensatory wavefront curvature based on a distance between the first communications terminal and the second communications terminal, a wavelength of the wavefront, and respective aperture sizes of the first communications terminal and the second communications terminal.

11. The method of claim 10 , further comprising:

determining an updated distance between the first communications terminal and the second communications terminal; and

adjusting the compensatory wavefront curvature based on the updated distance.

12. The method of claim 11 , wherein the updated distance is determined based on timing information received by the first communications terminal from the second communications terminal.

13. The method of claim 8 , wherein the generated wavefront has a beam waist midway between the first communications terminal and the second communications terminal.

14. The method of claim 8 , wherein a radius of curvature of the generated wavefront when received at the second communications terminal is equal to a distance between the first communications terminal and the second communications terminal.

15. A non-transitory machine-readable medium on which instructions are stored, the instructions, when executed by one or more processors, cause the one or more processors to perform a method of generating an outgoing communications beam at a first communications terminal, the method comprising:

determining a link axis for communication with a second communications terminal based on a received optical communications beam;

identifying a compensatory wavefront curvature for mitigating cross-coupling; and

generating a wavefront of an outgoing optical communications beam using a plurality of phase shifters of an optical phased array (OPA) architecture based on the determined link axis and the compensatory wavefront curvature.

16. The medium of claim 15 , wherein the method further comprises transmitting the outgoing optical communications beam to the second communications terminal.

17. The medium of claim 15 , wherein identifying the compensatory wavefront curvature includes determining the compensatory wavefront curvature based on a distance between the first communications terminal and the second communications terminal, a wavelength of the wavefront, and an aperture sizes of the first communications terminal or the second communications terminal.

18. The medium of claim 17 , wherein the method further comprises:

determining an updated distance between the first communications terminal and the second communications terminal; and

adjusting the compensatory wavefront curvature based on the updated distance.

19. The medium of claim 15 , wherein the generated wavefront has a beam waist midway between the first communications terminal and the second communications terminal.

20. The medium of claim 15 , wherein a radius of curvature of the generated wavefront when received at the second communications terminal is equal to a distance between the first communications terminal and the second communications terminal.