We are developing  a new type of bolometric detector for millimeter and submillimeter wavelengths. The detector is a variant of transition edge sensors (TES), which have recently been used as microcalorimeters from the near-IR to the X-ray. In this version of the TES, we couple radiation from a planar antenna directly to a superconducting thin film with dimensions of a few 10's of microns. At low temperatures, the thermal isolation between the electrons and the lattice in 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 the system.