Planar antenna-coupled transition-edge hot electron microbolometer

We describe a new type of bolometric detector for millimeter and submillimeter wavelengths. the detector is a variant of the Transition Edge Sensor (TES), which has recently been used to build bolometers. In this version of the TES, we couple radiation from a planar antenna to an absorbing normal metal film which is electrically connected to a superconducting thin film. The lateral dimensions of the absorber and TES are similar to10 microns. At low temperatures, the thermal isolation between the electrons and the lattice in the absorber and the superconductor allows the electrons to heat up. We call this device a Transition-edge Hot-electron Microbolometer (THM). These detectors could have numerous advantages for low-background measurements in the far-IR, such as, background-limited sensitivity, short time constant, wide spectral range, immunity to cosmic rays, low microphonic noise and simple readout electronics. We are currently building a low-frequency scale model of the planar antenna to characterize microwave properties of the system.