A Terahertz Source of Radiation to Open Space Based on a Long Josephson Junction

An electromagnetic source of terahertz radiation on the basis of a tunnel long Josephson junction was proposed and experimentally studied. Output radiation was transmitted to open space by means of a slot antenna, which was located on the same microcircuit with the junction and matched with the collecting lens. Several Oscillator structures designed for operation within the frequency ranges of 250–410, 330–530, and 390–700 GHz with the possibility of continuous frequency tuning were manufactured and tested. The amplitude-frequency characteristics of output radiation with a spectral resolution of nearly 0.1 MHz were studied with the use of a terahertz-spectrometer based on a superconducting receiver. The study of transmitting antenna characteristics throughout the entire bandwidth was performed with the use of a cooled highly sensitive silicon based bolometer. The experimental results correspond to numerical calculations.