A Frequency Domain Infrared Superconducting Transmission Line (FIRST) detector is comprised of a folded superconducting transmission line (36) interposed between a bottom electrode (32) and a top, radiation absorbing electrode (40). Dielectric layers (34, 38) separate the transmission line from the top and bottom electrodes. An optically induced change in the kinetic inductance of the transmission line shifts the transmission line phase velocity and resonant frequency. The shift in resonant frequency attenuates the propagating wave amplitude proportionally to the product of the transmission line Q and the frequency shift. A stacked pair of such detectors (50), sharing a common ground electrode (60), is disclosed to provide an inherent rejection of noise events due to ionizing radiation such as gamma radiation and package-generated Compton electrons.
Superconducting multilayer architecture for radiative transient discrimination