A 0.2–0.5 THz heterodyne receiver based on a photonic local oscillator and a superconductor-insulator-superconductor mixer

We have demonstrated that a superconductor-insulator-superconductor (SIS) mixer pumped by a photonic local oscillator (LO) covers the whole frequency range of 0.2-0.5 THz. In the bandwidth of 74 % of the center frequency, this single-band receiver exhibits the noise temperature of T_RXles20hf/k_B, where h is Planckpsilas constant, f the frequency, and k_B Boltzmann constant. Resultant T_RX is almost equal to T_RX of the identical SIS mixer pumped by three conventional multiplier-based LOs which share 0.2-0.5 THz band. This technique will contribute to simple, wide-band, and low-noise heterodyne receivers in the terahertz region.