Strongly polarized quantum well infrared photodetector with metallic cavity for narrowband wavelength selective detection

A quantum well-integrated metallic microcavity infrared photodetector is designed and fabricated to achieve highly polarized narrowband wavelength selective detection. Linear grooves are etched on top of the mesa and then the whole device is completely coated with Ti/Au to form an open metallic microcavity, and the resonant mode of the metallic cavity can be detected by the embedded quantum well active layer. The obtained devices show very narrow wavelength selective detection ability as well as strong polarization-dependent characteristics. High performances such as a quality factor of 60 and a polarization extinction ratio of 146 are noticed. Our work provides a promising basis for developing highly integrated infrared cameras with a remarkable performance.