Submillimeter-wave Camera using SIS Photon Detectors

Under collaboration between NAOJ and RIKEN, we have developed SIS photon detectors in submillimeter-wave. Band-pass response at 650 GHz is designed with distributed junction array. We have evaluated a nine-element detector array at 0.3 K under background loading. The measured performance is close to the shot noise limit of background photo current with optical NEP of about 10^-15 W/Hz^0.5. The same detector gives NEP of about 10^-14 W/Hz^0.5 at 4.2 K under thermal shot noise limit. A superconductive imaging submillimeter camera with nine detector elements, SISCAM-9, is successfully operated on a submillimeter-wave telescope.