Imaging and Spectroscopic Sensing with Low-Repetition-Rate Terahertz Pulses and GaN TeraFET Detectors
Int. J. Infrared Millimeter Terahertz Waves, vol. 39, no. 3, pp. 262-272 (2018).
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Aiming for non-destructive testing and security applications, we investigate transmission-mode imaging and spectroscopic sensing using terahertz (THz) pulses from a commercial optical parametric oscillator (OPO) in combination with THz detectors based on antenna-coupled field-effect transistors (TeraFETs). The Q-switched OPO generates quasi-continuous-wave THz pulses with a peak power of up to 1 W at a repetition rate between 12 and 90 Hz. The pulses are frequency-tunable between 0.7 and 2.6 THz with a typical linewidth of 50 GHz. We explore detection with fast GaN/AlGaN TeraFETs which hold the potential for multi-pixel and homodyne detection.
1 Physikalisches Institut, Goethe-University Frankfurt, Frankfurt am Main, Germany
2 Lehrstuhl für Höchstfrequenztechnik, University of Siegen, Siegen, Germany
3 M Squared Lasers, Glasgow, Scotland
4 Center for Physical Sciences and Technology, Vilnius University, Vilnius, Lithuania
5 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik (FBH), Berlin, Germany
THz detection, Optical parametric oscillator, Field effect transistor, THz imaging, THz spectorscopy.