Patent ID: 6157042
Filing Date: 2000-12-05
Classification: B82Y,H01L

Abstract:
A quantum well infrared radiation photodetector, comprising:a plurality of elongate, multiple quantum well infrared radiation absorbing elements, each of said elements having first and second opposite longitudinal surfaces,said multiple quantum well elements comprising a diffraction grating for said infrared radiation,a first contact which includes a plurality of planar electrically interconnected strips respectively in contact with and extending along said first surfaces of said multiple quantum well elements,a second contact electrically connected to said second surfaces of said multiple quantum well elements,said first contact and said second contact positioned on opposite longitudinal sides of each of said multiple quantum well elements to provide current flow through said elements in a direction substantially transverse to an axis of said elements,a planar reflector for said infrared radiation, said reflector positioned on an opposite side of said second contact from said multiple quantum well elements; andan optical cavity enhancement coating having a refractive index of 2.5 or less applied to the longitudinal surfaces,wherein a thickness of said optical cavity enhancement coating is selected such that said infrared radiation is concentrated in said multiple quantum well elements forming said diffraction grating.