SAMOP 2023 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 59: Poster IV
Q 59.75: Poster
Thursday, March 9, 2023, 16:30–19:00, Empore Lichthof
Development and characterization of a 2D THz-imaging system based on a 3D printed telecentric f-theta-lens — •Viola-Antonella Zeilberger1, Konstantin Wenzel1, Sarah Klein2, Martin Traub2, Robert B. Kohlhaas1, and Lars Liebermeister1 — 1Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Einsteinufer 37, 10587 Berlin, Germany — 2Fraunhofer Institute for Laser Technology ILT, Steinbachstraße 15, 52074 Aachen, Germany
In recent years, terahertz (THz) time-domain spectroscopy (TDS) has become an established tool for various applications, of which non-destructive layer thickness measurements and defect localization are of particular interest. These applications require rapid 2D imaging. Currently, 2D THz imaging is realized by translating either the single point sensor or the sample, which limits the measurement speed. In this work, we present a THz scanning system based on mechanical beam steering by a motorized gimbal mirror and a telecentric f-theta lens. This system contains a commercial THz-TDS system with a photoconductive THz transceiver as the sensor head. The lens fabricated by a 3D printer using a cyclic olefin copolymer (TOPAS) is designed to scan an area of 1.5 cm x 1.5 cm. We characterize this lens by investigating its focusing properties, the f-theta distortion, and scattering losses caused by the 3D printing process. We find that our scanning system offers diffraction-limited imaging up to 2 THz and satisfies the f-theta condition very well. Hence, this approach offers simple, cost-effective THz-imaging with the potential for high scanning rates.