A Passive, Fully Staring THz Video Camera Based on Kinetic Inductance Bolometer Arrays

Abstract

Current state-of-the-art security video cameras operating in the THz regime employ up to a few hundred detectors together with optomechanical scanning to cover an adequate field-of-view for practical concealed object detection. As a downside, the scanning reduces the integration time per pixel compromising sensitivity, increases the complexity, and reduces the reliability of the system. In contrast to this, we demonstrate a video camera, for the first time, basing its operation on the concept of a fully-staring 2D detector array with a single detector element responsible for a single imaged pixel. The imaging system is built around the detector technology of kinetic inductance bolometers, allowing the operation in the intermediate temperature range > 5 K and the scale-up of the detector count into multi-kilo-pixel arrays and beyond. The system is designed for a field-of-view of 2 × 1 m 2 and an imaging distance of 2.5 m. We describe the main components of the system and show images from concealed object experiments performed at a nearvideo rate of 9 Hz.

Roadmap of Terahertz Imaging 2021

“…A prototype of a security scanner, also based on kinetic inductance detectors, was recently introduced in Reference [415]. It has no mechanical scanning unit, but uses its 8712 detectors in a 20 × 10 cm 2 array in "full-staring" mode.…”

High-throughput terahertz imaging: progress and challenges

“…QCD imagers have provided the highest sensitivity among all demonstrated terahertz imagers with NEP levels as low as 10 − 20 W/√Hz (sensitivities up to 10 20 √Hz/W) 52 , 53 . The high sensitivity of terahertz image sensors based on superconductor and photon detectors enables fully staring passive imaging, while requiring operation at cryogenic temperatures 51 . Different from the time-multiplexing readout scheme used in TES imagers, KID, KIB, and QCD imagers adopt a frequency-multiplexing readout scheme, where a common feedline connects all the pixels and greatly reduces the complexity.…”

A Compact W-Band Low-Noise Radiometry Sensor for a Single-Pixel Passive Millimeter-Wave Imager

“…There are systems using bolometers as sensors. Bolometer detectors used at millimeterwave (mmW) frequencies are not in commercial production yet, and cooling of the detectors is one of the biggest obstacles to their use [14,15]. Direct diode detection receivers have a wide operating frequency band, and therefore a high thermal resolution [16].…”