VOLTAGE-TUNABLE MULTIPLE-QUANTUM-WELL PHOTODETECTOR VERTICALLY INTEGRATED WITH VOLTAGE-TUNABLE MULTIPLE-QUANTUM-WELL FILTER

We present a n-i[multiple quantum well (MQW)]-p-i(MQW)-n device wherein the bottom MQW functions as a voltage-tunable photodetector and the top MQW functions as a voltage-tunable filter, allowing enhanced detectivity at the exciton wavelength compared to photon energies below or above the band gap. Thus this device more closely approximates a true single wavelength, voltage-tunable photodetector. We achieve about 2-1 selectivity over a tuning range of 14 nm with 12 V operation.