HTSC FILMS AS FAST-RESPONSE IR DETECTORS

HYPRES PROPOSES A PROGRAM TO RESEARCH, DEVELOP, AND DEMONSTRATE HIGH TEMPERATURE SUPERCONDUCTING (HTSC) THIN FILMS AS FAST-RESPONSE IR DETECTORS. HTSC FILMS HAVE POTENTIAL FOR IR DETECTION OFFERING SEVERAL ADVANTAGES OVER EXISTING IR SENSING TECHNOLOGIES: (1) DETECTION TO LONGER WAVELENGTHS, UP TO 50 MICROMETERS; (2) REDUCED CRYOGENIC CONSTRAINTS SIGNIFICANTLY SIMPLIFYING SYSTEM DESIGN AND IMPLEMENTATION; (3) A NON-EQUILIBRIUM DETECTION MECHANISM IMPLYING EXTREMELY FAST RESPONSE TIMES - BELOW A NANOSECOND - POTENTIALLY CRITICAL IN HIGH SPEED MULTIPLE-TARGET DETECTION AND TRACKING. HTSC FILM RESPONSE TO IR RADIATION OCCURS THROUGH TWO MECHANISMS: BOLOMETRIC (HEATING), AND NON-EQUILIBRIUM. RECENT EXTENSIVE RESEARCH BY NUMEROUS LABORATORIES HAS FAILED TO LEAD TO A CONSENSUS ON THE PREDOMINANT MECHANISMS AND POTENTIAL OF THE TECHNOLOGY. THIS LACK OF CONCLUSIVE RESULTS IS DUE LARGELY TO THE EXTREMELY WIDE VARIATION IN MATERIAL CHARACTERISTICS OF THE SMAPLES TESTED. THIS PROPOSAL FOCUSES ON THE NON-EQUILIBRIUM MECHANISM WITH ITS SIGNIFICANT ADVANTAGES IN VERY FAST RESPONSE TIMES AND RELAXED CRYOGENIC REQUIREMENTS. IN PHASE I HYPRES WILL CONDUCT THEORETICAL AND EXPERIMENTAL STUDIES TO ESTABLISH THE EXISTENCE AND VIABILITY OF A NON-EQUILIBRIUM MECHANISM. IN PHASE II, EXTENSIVE MATERIALS ENGINEERING AND OPTIMIZATION WILL BE CARRIED OUT TO MAXIMIZE THE RESPONSIVITY, AND PROVIDE A SYSTEM DEMONSTRATION FOR IR HTSC DETECTOR ARRAYS.