In this Phase II program, the feasibility of developing and characterizing highly sensitive and high speed non-thermal quantum detectors in the 1-10 um wavelength region using high temperature Bi-Ca-Sr-Cu-O superconducting thin film, will be examined. These materials, because of the low band gap energy and resistance are inherently capable of detecting extremely high speed signals (GHz) over a wide wavelength range down to 100 um. Furthermore, the high transition temperature allows them to operate efficiently at liquid nitrogen temperature without any compromise on their characteristics. In the program, extremely smooth and optically semi-transparent superconducting film as thin as 80 nm will be deposited on suitable substrates by plasma assisted laser deposition technique. In order to improve the responsivity of the detector, these films will be patterned in a meander shape by laser induced etching process. Both nanosecond and picosecond laser pulses at various wavelengths ranging from 0.3 um to 10.6 um will be used to measure the temporal as well as wavelength dependence of the non-equilibrium response. The responsivity of the detector is estimated to be 10000 v/w with ultimate response time of 1 picosecond.
