A superconductor-insulator-normal metal bolometer with microwave readout suitable for large-format arrays

We demonstrate high bandwidth and low-noise readout of a superconductor-insulator-normal metal-insulator-superconductor hot-electron bolometer element. We measure a noise equivalent temperature of better than 0.6 muK/Hz(1/2) and infer an electrical noise equivalent power of 7 X 10(-17) W/Hz(1/2) for a normal-metal volume of 4.5 mum(3) at an operating temperature of 270 mK. Using a pulsed bias technique we measure a thermal time constant of 1.2 mus at 270 mK. The microwave readout method we employ is compatible with large-format arrays of 10(3)-10(5) pixels required by future far-infrared space and ground-based observatories. (C) 2005 American Institute Of Physics.