Submillimeter wave detection with high temperature superconducting bolometers

We have fabricated and characterized a planar antenna-coupled microbolometer working at the resistive transition edge of a HTc superconducting film for use as a submillimeter wave detector. A log-periodic antenna was used to couple the incoming radiation to a YBaCuO thin film microbridge. The performance of the antenna and the bolometer response were obtained by using a 119 µm H2O laser source. Both the radiation pattern directivity and the detector responsivity were clearly improved by irradiating the antenna from the dielectric substrate side by means of a hyper-hemispherical silicon lens