Silva, J., Ploschner, M., Bertling, K. et al. (18 more authors) (2025) Subwavelength 3D terahertz imaging with a single-pixel laser transceiver. Optics Express, 33 (10). pp. 21938-21950. ISSN 1094-4087
Abstract
Terahertz imaging holds great potential for non-destructive material inspection, but practical implementation has been limited by resolution constraints. In this study, we present a single-pixel THz imaging system based on a confocal microscope architecture, utilizing a quantum cascade laser as both transmitter and phase-sensitive receiver. We demonstrate, for the first time to the best of our knowledge, that laser feedback interferometry-based imaging systems achieve enhanced lateral and axial resolution compared to conventional confocal imaging. Specifically, our approach yields a twofold improvement in lateral resolution, reaching λ/2, and a two-order-of-magnitude enhancement in axial resolution, from 25λ to beyond λ/5, through interferometric phase detection. The system can produce a 0.5 megapixel image in under three minutes, surpassing both raster-scanning single-pixel and multipixel focal-plane array-based imagers. Coherent operation enables simultaneous amplitude and phase image acquisition, and a custom visualization method links amplitude to image saturation and phase to hue, enhancing material characterization. A 3D tomographic analysis of a silicon chip reveals subwavelength features, demonstrating the system’s potential for high-resolution THz imaging and material analysis. This work overcomes the resolution limits of conventional lens-based imaging systems, by enabling rapid, high-fidelity imaging of subwavelength features beyond the diffraction limit.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2025. This is an open access article under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Electronic & Electrical Engineering (Leeds) |
Funding Information: | Funder Grant number MRC (Medical Research Council) MR/S016929/1. EPSRC (Engineering and Physical Sciences Research Council) EP/J002356/1 EPSRC (Engineering and Physical Sciences Research Council) EP/P021859/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 29 Apr 2025 12:49 |
Last Modified: | 30 May 2025 13:38 |
Status: | Published |
Publisher: | Optica Publishing Group |
Identification Number: | 10.1364/oe.561713 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:225882 |