Direct-detection free-space optical communications link using 1 mu m wavelength laser diode transmitter

The performance of a 1.047 mu m wavelength semiconductor laser diode in a 50 Mbps free-space communications experiment is reported. This laser diode at 1.047 mu m makes it possible to construct high-power master oscillator power amplifier (MOPA) transmitters for space communications. The MOPA system would consist of the diode and a Nd-doped crystal amplifier. A 200 photon/bit sensitivity at a bit error rate of 10/sup -6/ is demonstrated and the performance parameters are characterized pertinent to the construction of a MOPA laser. This is believed to be the highest direct direction sensitivity at this wavelength reported to date.<
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