Optical and electrical characterization of a large kinetic inductance bolometer focal plane array

Sub-THz imaging techniques are currently emerging with applications especially in security screening requiring higher throughput in mass transit and public areas. In the context of person imagers, the field of view and the spatial resolution set the requirement for the number of image pixels. We perform an experimental feasibility study on a fully staring radiometric camera with one detector per image pixel. The aim is to avoid the shortcomings characteristic of optomechanical scanners with a limited number of detectors. Our approach is based on superconducting kinetic inductance bolometer arrays. We demonstrate successful fabrication and operation of a focal plane array with 2500 nanomembrane-integrated bolometers, and a compatible optical system enabling standoff imaging at the distance of 5 m. We characterize the system in terms of radiometric contrast and spatial resolution.