An optical transition-edge sensor with high energy resolution

Abstract Optical transition-edge sensors (TESs) have shown an energy resolution for resolving the number of incident photons at telecommunication wavelength. However, a higher is required biological imaging and microscopic spectroscopy. In this study, we tested Au/Ti (10/20 nm) bilayer TES that showed high resolution. The was achieved by lowering critical temperature T c to 115 mK, resultant 67 meV full width half maximum (FWHM) 0.8 eV. When reduced theoretical would scale up 30 FWHM, considering typical optical TESs 150 300 mK. To investigate difference between expectation (30 meV) measured value (67 meV), complex impedance current noise TES. We found excess Johnson in TES; term M 1.5 bias point where resistance 10% normal resistance. For reference, above mentioned compared with showing (156 FWHM). also discussed factors improved or inhibited