QUANTUM-WELL INFRARED PHOTODETECTOR WITH OPTICAL OUTPUT

A quantum well infrared photodetector which converts long-wavelength i nfrared radiation into short-wavelength infrared (or visible) radiatio n is considered. The quantum well infrared photodetector utilizes an i ntraband absorbtion of radiation in a quantum well in the emitter and interband emission in either classical or quantum well in the collecto r. It is shown that the efficiency of energy conversion of short-wavel ength radiation into long-wavelength radiation can be about unity.