Performance of cryogen-free THz detection and passive imaging systems

We report the measured performance characteristics of a broadband (0.2 - 10 THz) bolometer instrument based on thin film superconducting technology. The technology is designed for operation both in liquid helium cryostats but also in an electrical cooling platform. We report a number of significant advantages that accrue to superconducting technology compared to semiconductor devices. Single pixel systems are now commercially available, and array devices are in development. We also report the performance of “KIDCAM,” a passive THz imaging camera based on Lumped Element Kinetic Inductance Detectors (LEKIDs) operating at 250mK. Again no liquid cryogens are consumed. Furthermore the instrument can be automatically operated and remotely controlled and interrogated. Multi-layer mesh filters are an enabling technology, providing both high in-band transmission efficiency and high attenuation of unwanted frequencies - both aspects are crucial to achieve high sensitivity in a large optical throughput instrument. This technology shows great potential for deployment into non-laboratory operating conditions.