Direct detection of the Josephson radiation emitted from superconducting thin-film microbridges

Abstract
We report direct measurements of the Josephson radiation emitted in X band from a superconducting thin‐film microbridge coupled to a resonance cavity. Power is emitted if one of the harmonics of the Josephson frequency is in the bandwidth of the receiver. The maximum power emitted during our experiment was 10−13 W. The Josephson radiation could easily be detected at frequencies off resonance.