Quantum grid infrared photodetector

摘要

A quantum grid infrared photodetector (QGIP) includes a semiconductor substrate with a quantum well infrared photodetector (QWIP) mounted thereon. The QWIP includes a lower contact layer formed on a planar surface of the substrate and a stack of alternate planar barrier layers and planar well layers sandwiched between the lower contact layer and an upper contact layer. The planes of the barrier layers and well layers are substantially parallel to the plane of the planar surface. A plurality of single-slit diffraction units are arranged as a grid in the stack for diffracting incident infrared radiation into a continuum of radiation components directed toward the well layers at different angles with respect to the planes of the well layers. The diffraction units are composed of cavities that extend through the barrier layers, the well layers and the upper contact layer. The cavities have rectangular, square and round shapes and are arranged in rows and columns to form the grid.