Abstract-Terahertz imaging with room-temperature terahertz difference-frequency quantum-cascade laser sources

Atsushi Nakanishi, Kazuue Fujita, Kazuki Horita, and Hironori Takahashi

Fig. 1 Properties of THz DFG-QCL at –30 °C: (a) Spectrum, (b) far-field profile, (c) horizontal and vertical sections of the beam profile.

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-3-1884

We demonstrate high-quality non-destructive imaging using a broadband terahertz quantum cascade laser source based on Cerenkov difference-frequency generation. The source exhibited ultra-broadband terahertz emission spectra, as well as a single-lobed Gaussian-like far-field pattern at –30 °C. These features allowed us to build a compact imaging system with a high spatial resolution, from which a nearly theoretical minimum beam spot size was obtained. As a result, we achieve well-resolved, high-contrast images of objects obscured by opaque materials. We also achieved terahertz imaging with the THz DFG-QCL operated at room temperature.

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