Passive terahertz camera for standoff security screening
Research output: Contribution to journal › Article › Scientific › peer-review
We describe the construction and performance of a passive, real-time terahertz camera based on a modular, 64-element linear array of cryogenic hotspot microbolometers. A reflective conical scanner sweeps out a 2m×4m (vertical×horizontal) field of view (FOV) at a standoff range of 8m. The focal plane array is cooled to 4K in a closed cycle refrigerator, and the signals are detected on free-standing bridges of superconducting Nb or NbN at the feeds of broadband planar spiral antennas. The NETD of the focal-plane array, referred to the target plane and to a frame rate of 5s−1, is 1.25K near the center of the array and 2K overall.
Grossman, E., Dietlein, C., Ala-Laurinaho, J., Leivo, M., Grönberg, L., Grönholm, M., Lappalainen, P., Rautiainen, A., Tamminen, A., & Luukanen, A. (2010). Passive terahertz camera for standoff security screening. Applied Optics, 49(19), E106-E120. https://doi.org/10.1364/AO.49.00E106