Avalanche transistors to generate jitter-free nanosecond current pulses for driving GaAs laser diodes at low temperatures

GaAs laser diodes can be modulated at very high frequencies Transistors operating in the avalanche mode are capable of producing very fast jitter-free pulses. The Current output is comparable to that required by GaAs laser diodes at low temperatures. It is observed that avalanche-transistor performance is not significantly affected by cooling to low temperatures. It can therefore be used to directly drive a laser diode at low temperatures. This overcomes the problems associated with transmission of very fast current pulses at low impedance levels.