RESONANT CAVITY FIELD ENHANCING BOUNDARY

摘要

An electromagnetic sensor (20) includes top and bottom longitudinal contacts (24, 26) on opposite surfaces of an electromagnetic absorbing structure (22). A grating (28) is provided to diffract the electromagnetic radiation. A reflector (30) operating in conjunction with the grating (28) creates an electromagnetic cavity leading to the formation of a standing electromagnetic wave (32) at a resonant frequency within the electromagnetic absorbing material. The addition of a highly electrically conductive layer (36B) to the perimeter of the electromagnetic absorbing material further defines the electromagnetic cavity. In particular, the conductive layer (36B) serves to create boundary conditions which enhance the absorption of electromagnetic radiation. Such a design applies to a class of electromagnetic sensors known as quantum well infrared photodetectors (QWIPs).