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

• Published in: IEEE transactions on terahertz science and technology 2021-01, Vol.11 (1), p.101-108
• Main Authors: Luomahaara, Juho, Sipola, Hannu, Gronberg, Leif, Mayra, Aki, Aikio, Mika, Timofeev, Andrey, Tappura, Kirsi, Rautiainen, Anssi, Tamminen, Aleksi, Vesterinen, Visa, Leivo, Mikko, Gao, Feng, Vasama, Hannu, Luukanen, Arttu, Hassel, Juha
• Format: Article
• Language: English
• Subjects: Arrays; Bolometer; Bolometers; Camcorders; Cameras; Detectors; Field of view; focal plane array (FPA); Inductance; Instruments; kinetic inductance; Kinetic theory; Object recognition; Pixels; radiometry; Scanning; security screening; Sensors; THz imaging; THz video camera
• ISSN: 2156-342X; 2156-3446
• DOI: 10.1109/TTHZ.2020.3029949

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 2-D 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 multikilo-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 near-video rate of 9 Hz.