Passive detection and imaging of human body radiation using an uncooled field-effect transistor-based THz detector

  • This work presents, to our knowledge, the first completely passive imaging with human-body-emitted radiation in the lower THz frequency range using a broadband uncooled detector. The sensor consists of a Si CMOS field-effect transistor with an integrated log-spiral THz antenna. This THz sensor was measured to exhibit a rather flat responsivity over the 0.1–1.5-THz frequency range, with values of the optical responsivity and noise-equivalent power of around 40 mA/W and 42 pW/√Hz, respectively. These values are in good agreement with simulations which suggest an even broader flat responsivity range exceeding 2.0 THz. The successful imaging demonstratestheimpressivethermalsensitivitywhichcanbeachievedwithsuchasensor. Recording of a 2.3×7.5-cm2-sized image of the fingers of a hand with a pixel size of 1 mm2 at a scanning speed of 1 mm/s leads to a signal-to-noise ratio of 2 and a noise-equivalent temperature difference of 4.4 K. This approach shows a new sensing approach with field-effect transistors as THz detectors which are usually used for active THz detection.

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Author:Dovilé Čibiraitė-Lukenskienė, Kęstutis Ikamas, Tautvydas Lisauskas, Viktor KrozerORCiDGND, Hartmut RoskosORCiDGND, Alvydas LisauskasORCiDGND
Parent Title (English):Sensors
Place of publication:Basel
Document Type:Article
Date of Publication (online):2020/07/22
Date of first Publication:2020/07/22
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2020/08/26
Tag:THz detection; TeraFET; human-body radiation; passive imaging; terahertz; field-effect transistor
Page Number:14
First Page:1
Last Page:14
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik
Licence (German):License LogoCreative Commons - Namensnennung 4.0