Development of an Optical Transition-Edge Sensor Array

Transition-edge sensors (TESs) exhibiting high energy resolution for single optical photons have been applied to photon-counting microscopy for biological imaging. This paper discusses the development of TES arrays with large effective areas to expand the field of view of photon-counting microscopy and has fabricated an optical TES array comprising a Ti/Au bilayer on a Si substrate. Thermal interference due to Joule power did not affect the time constant and energy resolution of a detector in the TES array, even though the Joule power in the detector was changed by 23%. The photon signal crosstalk between adjacent detectors was − 40 dB which was negligible. Heat conduction through the Si substrate was dominant in the photon signal crosstalk between adjacent detectors.