A tunable sub-terahertz wave generation and detection system with a photomixer and a high-Tc Josephson junction

We have fabricated a generation and detection system of tunable sub-terahertz electromagnetic waves using a photomixing technique combined with a high-T-c Josephson junction. The frequency of the electromagnetic wave generated using the photomixing technique was monitored by a YBCO Josephson junction detector, and was obtained from the voltage interval of the Shapiro steps that appear in the current-voltage characteristics of the junction. We succeeded in wideband operation in a frequency range from 58 to 161 GHz with a uni-travelling-carrier photodiode as a photomixer, and discuss the coupling efficiency between the radiation source and the Josephson detector. Such a technique should become the basic technology for THz applications, such as imaging systems and wireless communication.