Sensitive, low-noise superconducting infrared photodetector

U.S. Patent Number: 5331162

Abstract: A superconducting infrared photodetector employing SQUID (Superconducting Quantum Interference Device) measurement of fluxon flow in thin superconducting granular films to provide sensitive, low-noise detection of infrared radiation. The superconducting infrared photodetector includes a plurality of superconducting detector elements connected in parallel or series, means for supplying a bias current to the detector elements, and a digital or analog SQUID readout circuit. Each detector element includes a thin granular film of superconducting material which forms a randomly connected array of weakly coupled superconductors. The weakly coupled superconductors promote the formation of oppositely-polarized fluxons, which are driven to opposite sides of the film when subjected to the bias current. Incident radiation causes an increase in this fluxon flow, generating a voltage change. The voltage change is measured by the SQUID readout circuit to provide a sensitive, low-noise measurement of the amount of radiation incident on the detector elements.

Inventors: Silver; Arnold H. (Rancho Palos Verdes, CA), Leung; Michael (Lomita, CA), Lee; Gregory S. (Mountain View, CA), Simon; Randy W. (Belmont, CA), Sandell; Robert D. (Manhattan Beach, CA)

Assignee: TRW Inc. (Redondo Beach, CA)

Application Number: 07/796,555

Issued: 1994-07-19

Expired: 2006-07-19

Classes: 250/336.2 ; 250/338.1; 505/848; 505/849

Field of search: 250/336.2,338.1 505/848,849,870,874,846 357/5

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