Compact Superconducting Terahertz Source Operating in Liquid Nitrogen

Abstract

Sources of terahertz radiation (between the far infrared and microwave frequencies) are in high demand for a host of applications. The authors report on what is essentially a ``T-ray flashlight'', a compact and portable source of tunable, continuous terahertz light, employing a stack of intrinsic Josephson junctions in a cuprate superconductor as the emitter. This economical and convenient device can be driven by one everyday 1.5-V battery, and should facilitate airport security, nondestructive evaluation, and remote detection of trace gases, among other applications.