InGaAs-InAlAs multiple quantum well optical bistable devices using the resonant tunneling effect

New types of InGaAs-InAlAs multiple quantum well (MQW) optical bistable devices using the resonant tunneling effect are investigated. The bistability of these devices is obtained by the negative differential resistance (NDR) of the MQW resonant tunneling diodes (RTDs). Two types of MQW bistable devices are described. One is an MQW optical bistable device consisting of an MQW-RTD and an MQW modulator. Light-output-light-input bistable operation is obtained for this device at room temperature. The other is an InGaAs-InAlAs MQW resonant tunneling phototransistor (MQW-RPT), which shows a clear bistability in the collector-current-light-input characteristic. Inverter-type optical bistable operation with an on/off ratio of more than 10 dB is obtained by using the MQW-RPT as a laser driver. Optical memory operation is also demonstrated.<
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