Terahertz imaging at 77 K

Terahertz (THz) technology is receiving increasing attention around the world due to its important potential in many application areas. Novel compact solid-state sources and detectors are being sought for THz radiation and detection. We report the realization of a THz imager based on a high-T-c superconducting (HTS) Josephson detector working above liquid nitrogen temperature (77 K). The detector, made of a YBa2Cu3O7-x (YBCO) step-edge Josephson junction, is coupled to a thin-film ring-slot antenna and a hemispheric silicon lens. Images of high visual quality are obtained which demonstrate unique properties of THz radiation such as the sensitivity to water content and the ability to penetrate packaging materials. The results should stimulate further research leading to the development of a HTS superconducting THz imaging system.