Ground-to-satellite laser communication program at CRL using adaptive optics

This paper reports the application of an adaptive optics (AO) system to our ground-to-satellite laser communication system. We believe that the AO system is one of the best solutions to compensate the degradation of the laser beam due to an atmospheric turbulence and to realize a high bit-rate laser communication system. In the first stage of developing and designing the AO system, we have measured an atmospheric turbulence at Communications Research Laboratory (CRL), located in the west suburb of Tokyo. It shows that Fried's coherence length is about 5 cm in winter and 9 cm in summer at 0.8 mu m observing wavelength. We also simulated the AO performance of the laser communication system using our results of the atmospheric measurement.