Michael Sherman

US Patent:

50971212, Mar 17, 1992

Filed:

Jan 24, 1991

Appl. No.:

7/645428

Inventors:

Michael G. Sherman - Corona CA
Craig S. Tindall - Irvine CA

Assignee:

Rockwell International Corp. - El Segundo CA

International Classification:

H01J 4014

US Classification:

250211J

Abstract:

An impurity band conduction (IBC) detector having a substrate and a thin layer IR active region is provided with a beveled edge for increasing the quantum efficiency of the detector. The edge of the transparent detector substrate is beveled at an angle equal to or greater than the critical angle for total internal reflection of radiation in the material of the substrate and active region of the detector. The radiation is directed into the detector normal or nearly normal to the beveled edge. The radiation travels the length of the detector due to total internal reflection within the detector. As a result, the radiation passes through the IR active region of the detector a plurality of times, thereby increasing the probability that a photon will be absorbed by an impurity within the IR active region and sensed by the detector. The efficiency of the IBC detector is further increased because the beveled edge provides a greatly increased surface area for focusing and aligning the incident radiation directed into the detector, thereby improving the efficiency of coupling the radiation to the detector.