Laser beam projection system with dynamic phase compensation

1. An apparatus comprising:

at least one processor configured to:

determine a wavefront phase profile of return illumination reflected from a remote object, the wavefront phase profile based on interference between Doppler-shifted local oscillator (LO) illumination and the return illumination;

calculate a wavefront error based on a comparison between (i) the determined wavefront phase profile of the return illumination and (ii) a desired wavefront phase profile of a high energy laser (HEL) beam; and

control a deformable mirror to at least partially compensate the HEL beam for the calculated wavefront error.

2. The apparatus of claim 1 , wherein the at least one processor is configured to:

determine a Doppler shift associated with the remote object; and

control generation of the Doppler-shifted LO illumination based on the determined Doppler shift.

3. The apparatus of claim 2 , further comprising:

a Doppler sensor configured to measure a Doppler frequency of the return illumination relative to non-Doppler-shifted LO illumination;

wherein the at least one processor is configured to determine the Doppler shift associated with the remote object based on an output of the Doppler sensor.

4. The apparatus of claim 2 , wherein the at least one processor is configured to control generation of Doppler-shifted HEL LO illumination based on the determined Doppler shift.

5. The apparatus of claim 4 , wherein the at least one processor is configured to control the deformable mirror to adjust a hitspot of the HEL beam on the remote object based on interference between the Doppler-shifted HEL LO illumination and HEL return illumination.

6. The apparatus of claim 2 , further comprising:

an electro-optic modulator configured to generate the Doppler-shifted LO illumination.

7. The apparatus of claim 1 , wherein the at least one processor is configured to decompose the wavefront error into separate tilt, focus, and higher-order components.

8. The apparatus of claim 7 , wherein the at least one processor is configured to:

control one or more fast steering mirrors according to the tilt component of the wavefront error;

control a focus mechanism according to the focus component of the wavefront error; and

control the deformable mirror according to the higher-order components of the wavefront error.

9. The apparatus of claim 7 , wherein the at least one processor is configured to control the deformable mirror according to the tilt, focus, and higher-order components of the wavefront error.

10. The apparatus of claim 1 , further comprising:

a focal plane array configured to measure an interference pattern associated with the interference between the Doppler-shifted LO illumination and the return illumination;

wherein the at least one processor is configured to determine the wavefront phase profile of the return illumination based on an output of the focal plane array.

11. A method comprising:

determining a wavefront phase profile of return illumination reflected from a remote object, the wavefront phase profile based on interference between Doppler-shifted local oscillator (LO) illumination and the return illumination;

calculating a wavefront error based on a comparison between (i) the determined wavefront phase profile of the return illumination and (ii) a desired wavefront phase profile of a high energy laser (HEL) beam; and

controlling a deformable mirror to at least partially compensate the HEL beam for the calculated wavefront error.

12. The method of claim 11 , further comprising:

determining a Doppler shift associated with the remote object; and

controlling generation of the Doppler-shifted LO illumination based on the determined Doppler shift.

13. The method of claim 12 , further comprising:

measuring a Doppler frequency of the return illumination relative to non-Doppler-shifted LO illumination;

wherein the Doppler shift associated with the remote object is based on the Doppler frequency.

14. The method of claim 12 , further comprising:

controlling generation of Doppler-shifted HEL LO illumination based on the determined Doppler shift.

15. The method of claim 14 , wherein controlling the deformable mirror comprises:

controlling the deformable mirror to adjust a hitspot of the HEL beam on the remote object based on interference between the Doppler-shifted HEL LO illumination and HEL return illumination.

16. The method of claim 12 , further comprising:

generating the Doppler-shifted LO illumination by modifying an output of a master oscillator using an electro-optic modulator.

17. The method of claim 11 , further comprising:

decomposing the wavefront error into separate tilt, focus, and higher-order components.

18. The method of claim 17 , further comprising:

controlling one or more fast steering mirrors according to the tilt component of the wavefront error; and

controlling a focus mechanism according to the focus component of the wavefront error;

wherein controlling the deformable mirror comprises controlling the deformable mirror according to the higher-order components of the wavefront error.

19. The method of claim 17 , wherein controlling the deformable mirror comprises:

controlling the deformable mirror according to the tilt, focus, and higher-order components of the wavefront error.

20. The method of claim 11 , further comprising:

measuring an interference pattern associated with the interference between the Doppler-shifted LO illumination and the return illumination;

wherein the wavefront phase profile of the return illumination is based on the interference pattern.