Experimental verification of an adaptive optical multi-aperture receive antenna for laser space communications

The feasibility of phased telescope arrays for coherent optical space communications is demonstrated by a proof-ofconcept laboratory experiment. The incident optical power is collected by four subtelescopes and coherently combined into a single monomode output fiber. The implemented optical receive array antenna is self-phasing, i.e. the optical subfield pistons are automatically adapted with respect to the direction of the incident wavefront. The telescope array is completely independent of any subsequent receiver and of the data modulation format employed. Our experimental setup operates at a wavelength of 1064nm. With an optical input power of 1nW per subaperture, the system efficiently combines the optical input subwaves and responds to a step-shaped change of the input wavefront direction within 1ms.