Terahertz electromagnetic spectroscopy using a high T/sub c/ Josephson junction

Novel sensitive detection of terahertz electromagnetic radiation using a high T/sub c/ YBa/sub 2/Cu/sub 3/O/sub 7-y/ (YBCO) Josephson junction is reported. The terahertz oscillator and the detector junction are fabricated on the same MgO bicrystal substrate. The Josephson ac effect enables the spectroscopic detection of incoming electromagnetic waves. The results from quasiparticle-injected YBCO superconductor represent the broad peaked structure around 1 THz.