Three-terminal operation analysis of exciton absorption reflection switches (EARS's)

The three-terminal operation of photonic-switching arrays consisting of multiple-quantum-well (MQW) modulators and heterojunction phototransistors (HPTs) connected with distributed Bragg reflectors (DBRs) is analyzed. NOR and OR gate characteristics are achieved by modifying the electrical connection between the MQW modulators and HPTs. A memory function is obtained by controlling DBR transmission. By using an optimum load resistor for the HPTs, switch-on and switch-off times are balanced, and minimum switching energy is obtained. Reduction of residual carrier concentrations in the collector layer of the HPTs and operating voltage of the MQW modulators give a switching energy as low as 1 fJ/ mu m/sup 2/.<
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