3-TERMINAL OPERATION ANALYSIS OF EXCITON ABSORPTION REFLECTION SWITCHES (EARSS)

Three-terminal operation of photonic switching arrays consisting of multiple-quantum-well (MQW) modulators and heterojunction phototransistors (HPT's) connected with distributed Bragg reflectors (DBR's) are analyzed and experimentally examined. It is shown that both NOR and OR gate characteristics are achieved by modifying the electrical connection between the MQW modulators and HPT's, and that a memory function is obtained by controlling DBR transmission. By implementing an optimum load resistor for the HPT's, both switch-on and-off times are balanced and minimum switching energy is obtained. Estimates indicate that reductions of residual carrier concentrations in the collector layer of the HPT's and operating voltage of the MQW modulators give a switching energy as low as 1 fj/mum2.