The avalanche phototransistor—A novel type of radiation detector and its potential use in optical communication systems

The possibility of triggering avalanche transistors by optical signals and the resulting electrical characteristics are presented. These avalanche phototransistor (APT) detectors are capable of generating nanosecond output pulses at high current levels. A series connection of an APT and injection laser is shown to operate as a simple PCM-regenerator circuit in optical communication systems.