Electronically steerable free space optical communication beams

An experimental 4.1 km optical atmospheric communication link has been in operation between the Imperial College of Science and Technology and University College London since mid-April 1988. The authors describe the design features and the performance of the link, gives the initial assessment of atmospheric propagation at a wavelength of 830 nm in a typically urban environment and report the initial results of electronic beam steering experiments which involve no moving parts.<
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