Use of semiconductor lasers in compact communication systems

A description is given of a voice communication system which utilizes an uncooled GaAs injection laser. Stable communication is provided by the system over distances up to 6 km for atmospheric signal attenuation up to 2.5 dB/km. The principal characteristics of the epitaxial laser are given for temperatures from –40 to +40°C and pulse repetition frequencies up to 10 kHz. The peak output power of the laser is 5 W. No deterioration in the operating characteristics has been found after 100 h. The total weight of the system, including a stand and a power supply unit, is 15 kg.