Terahertz imaging with a direct detector based on superconducting tunnel junctions

We demonstrated terahertz imaging using a direct detector based on niobium superconducting tunnel junctions (STJs). The detector is composed of linearly distributed junctions placed on a superconducting microstrip line and is integrated on two wings of a log-periodic antenna. We succeeded nondestructive imaging for an integrated-circuit card and dry material using the detector around its sensitivity peak (similar to 0.66 THz). The dynamic range was measured to be higher than 4x10(7) (76 dB). Thus, the STJ detector is applicable to high-sensitivity and high-speed terahertz imaging for various nondestructive inspection applications. (c) 2006 American Institute of Physics.