Field experiment of laser energy transmission and laser to electric conversion

In this paper, the authors report the result of the field experiment of laser power transmission over 500 m using different laser systems, i.e. CO₂, YAG, etc. The efficiency of energy transmission over a long time period under various meteorological conditions was measured. The authors have observed large and long time scale fluctuation of beam pointing. It is found that the position of laser beam at the receiving site is correlated to the temperature difference between laser path height and ground. The laser to electricity conversion experiment has been performed using GaAs, c-Si, tandem-type a-Si, and CuInSe₂ (CIS) solar cells. Finally, the authors briefly introduce the proposal on the space experiment of laser power transmission at the Japanese Experiment Module (JEM) on the International Space Station