Applied Physics Letters
Heterodyne detection of THz radiation with a superconducting hot-electron bolometer mixer
Alexei D. Semenov, Yu. P. Gousev, Rainer S. Nebosis, Karl Friedrich Renk, Pavel A. Yagoubov, Boris M. Voronov, Gregory N Gol'tsman, V. D. Syomash, Eugene M. Gershenzon
Abstract
We report on the use of a superconducting hot-electron bolometer mixer for heterodyne detection of terahertz radiation. Radiation with a wavelength of 119 μm was coupled to the mixer, a NbN microbridge, by a hybrid quasioptical antenna consisting of an extended hyperhemispherical lens and a planar logarithmic spiral antenna. We found, at an intermediate frequency of 1.5 GHz, a system double side band noise temperature of ≊40 000 K and conversion losses of 25 dB. We also discuss the possibilities of further improvement of the mixer performance.