A superconducting antenna-coupled hot-spot microbolometer

We report the electrical properties of an antenna-coupled niobium vacuum-bridge bolometer, operated at a temperature of 4.2 K, in which the thermal isolation is maximized by the vacuum gap between the bridge and the underlying silicon substrate. The device is voltage-biased, which results in a formation of a normal state region in the middle of the bridge. The device shows a current responsivity of −1430 A/W and an amplifier limited electrical noise equivalent power of 1.4×10−14 W/√Hz.Peer reviewe