Submillimeter-wave kinetic inductance bolometers on free-standing nanomembranes

We introduce a microwave submillimeter-wave detector based on an integrated micromesh absorber and superconducting kinetic inductance thermometer on a through-wafer released sub-micron thick membrane. Equilibrium operation achieved by thermal isolation through the membrane geometry enables operation at elevated thermal bath temperatures of 5-10 K. The bolometer operates in a phonon-noise limited regime with a measured noise equivalent temperature difference of below 10 mK at 1 s integration time, which is sufficient for radiometric imaging in terrestrial systems. We also measured and analyzed the bolometer frequency response in the band 0.1-1.4 THz. Performance improvements through further dimensional scale-down and temperature dependency are discussed.