Optical Transition Edge Sensors

—Towards High Sensitivity and Fast Detectors—

Abstract

Superconducting Transition Edge Sensors （TESs） are promising optical photon detectors, which can count infrared photons with energy information. TES characteristics are explained in terms of a readout system with a negative feedback circuit. The current status of the optical TES detector development is introduced. We also introduce the development of our Ir-TES. Further optimization of the readout circuit is anticipated by using the recent fast cryo-electronics.