Valavanis, A, Dean, P, Li, LH et al. (16 more authors) (2014) High-power (> 1 Watt) terahertz frequency quantum cascade lasers for stand-off imaging. In: SET-210 Specialist Meeting on Novel infrared laser technology for modern battlefield requirements. SET-210 Specialist Meeting on Novel infrared laser technology for modern battlefield requirements, 24-25 Jul 2014, Salisbury, UK. NATO
Abstract
Terahertz frequency quantum cascade lasers (THz QCLs) are compact electrically-driven semiconductor sources of radiation in the 1–5 THz (λ = 300–60 μm) band. Through a systematic optimisation of the device design and processing, we have recently demonstrated a world-record peak output power in excess of 1 W from a single facet at 10 K (more than double the previous record) and \textgreater 400 mW at 77 K. We review the development and performance of this laser, and consider a range of novel imaging techniques that could exploit high-powered THz emission. The first such technique senses the relatively weak scattered radiation from a powdered material, thus obtaining sensitivity to both the particle geometry and the bulk spectral absorption properties of the material, in good agreement with conventional THz time-domain spectroscopy. An alternative self-mixing technique is discussed, in which feedback of radiation into the laser cavity from an external object causes perturbations to the laser voltage, allowing ‘detector-free’, highly sensitive, confocal and phase-sensitive imaging of concealed three-dimensional surface morphologies.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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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) > Pollard Institute (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 15 Jan 2015 12:09 |
Last Modified: | 19 Dec 2022 13:30 |
Publisher: | NATO |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:82333 |