Switching characteristics of laser diode switch

Switching characteristics for laser diode switches controlled by the forward injection current have been studied. Pumping rate dependences for the internal gain and for the extinction ratio, defined as the ratio of output signal power to total power, were analyzed numerically and experimentally. They were in good agreement. Turn-on response time is determined mainly by the space-charge capacitance and was seen typically to be ten times the carrier lifetime. The fall time was almost equal to the carrier lifetime. A method to reduce turn-on response time by preshaping the drive pulse is also analyzed. The turn-on response time could be reduced to about 1 ns.