Experimental assessment of semiconductor lasers for optical data links in space

The suitability for intersatellite optical communication of four commercially available semiconductor lasers emitting at 830 nm was tested in order to establish operating parameters yielding high-power optical pulses. The near and far field patterns and the spectral distribution of the pulse energy were measured to characterize the laser types. For laser lifetime the choice of the coding format plays an important role. Results show that pulse position modulation ensures the longest lifetime for a given maximum pulse power. For the laser best-suited for the foreseen application, the maximum distance which can be bridged in space with 0.1 m diameter antennas at 10 Mbit/sec is 10,000 km are described.