Compensation of slowly varying wavefront aberrations of low-cost meter-scale optical communication receiver mirror systems is reported. Our goal is to reduce the surface wavefront error of a low-cost large aperture telescope mirror from multiple waves to about 1-wave or less peak-to-valley (P-V). Both spatial light modulators and monolithic deformable mirrors are applied in our active optical compensation systems. Spatial light modulators with only one wave stroke can compensate for aberrations of over 10-waves P-V by using 2π phase wraps, while deformable mirrors are limited to 10- wave aberrations (P-V), due to stroke limitations of commercially available systems. We demonstrate aberration compensations of a low-cost 0.6-m diameter mirror using a deformable mirror and a 0.3-m diameter telescope using a spatial light modulator. Upon aberration compensation, image quality is recovered close to the original, with the residual distortion limited by the diffraction efficiency. The laser beam spot size is reduced by a factor of four, and the measured received signal level is increased ten-fold.

Date Published: 24 February 2009
PDF: 7 pages
Proc. SPIE 7199, Free-Space Laser Communication Technologies XXI, 71990D (24 February 2009); doi: 10.1117/12.811894

Published in SPIE Proceedings Vol. 7199:
Free-Space Laser Communication Technologies XXI
Hamid Hemmati, Editor(s)