A Technique of Modulating Pulsed Semiconductor Lasers

This paper gives details of the pulse-position modulation technique as applied in the case of a pulsed room-temperature-operated GaAs laser diode for communication purposes. The input analog signal is converted into a digital format and information transmission takes place through the laser pulses occurring at different positions in time. Special care is taken to synchronize the receiver with the transmitter. At the receiver the analog information is reconstructed. The technique can be incorporated in the development of a short-haul point-point-to-point voice communication system using the laser diode.