Response properties at 2.525 terahertz using high-T-C Josephson junctions on silicon bicrystal substrates

Using high-T-c grain boundary Josephson junctions (GBJJs) made of YBa2Cu3O7 -delta deposited across silicon bicrystal boundary, we successfully demonst rated direct response at frequency as high as 2.525THz, and the operation t emperature up to 70K. Also, the effects of response on polarization of elec tromagnetic waves and the harmonic mixing properties are investigated. It i s found that there is no polarization dependence of the response for our hi gh-quality GBJJs, This result is favorable to the spectroscopy application. At frequency as high as 2.525THz, the high-order harmonic mixing at zero a nd finite bias voltage has been demonstrated.