Development of an Ir-TES for near infrared single photon counting

Abstract A photon-number resolving detector based on an iridium (Ir) transition-edge sensors (TES) for real time dose monitoring was designed and fabricated. The current–voltage relationship of the small Ir-TES, with an effective area of 7 μ m × 7 μ m , was measured and its electrothermal feedback operation was confirmed. This device had a transition temperature of 280 mK, which is higher than that of bulk Ir, because of the proximitisation effect. We also confirm that he signals of infrared photon response were measured.