Patent ID: 7135698

Claim:
A multi-spectral infrared radiation super-pixel photodetector including a plurality of sub-pixel photodetectors, each of the plurality of sub-pixel photodetectors comprising: a plurality of elements for absorbing at least two bands of infrared radiation, each of the plurality of elements being elongate, each of the plurality of elements having first and second opposite longitudinal surfaces, the at least two bands of infrared radiation incident upon the first surfaces of the plurality of elements; a plurality of strips respectively being in electrical contact with and extending along the first surfaces of the plurality of elements, the plurality of strips being electrically interconnected; a bottom contact being in electrical contact with the second surfaces of the plurality of elements, the plurality of strips and the bottom contact to provide for current flow through the plurality of elements in a direction substantially transverse to an axis of the plurality of elements; and a reflector for the at least two bands of infrared radiation, the reflector being disposed on an opposite longitudinal surface of the bottom contact from the plurality of elements, a bias voltage source, said bias voltage source selectively providing a plurality of external bias voltages, wherein a ratio between a photoresponse to each of the at least two bands of infrared radiation is a function of which of the plurality of external bias voltages is applied between the plurality of strips and the bottom contact, wherein the plurality of elements, the plurality of strips, the bottom contact and the reflector comprise a diffractive resonant optical cavity for the at least two bands of infrared radiation, and wherein a diffractive resonant optical cavity for a first sub-pixel photodetector of the plurality of sub-pixel photodetectors is different from a diffractive resonant optical cavity for a second sub-pixel photodetector of the plurality of sub-pixel photodetectors.