Valavanis, A, Dean, P, Lim, YL et al. (9 more authors) (2013) Self-Mixing Interferometry With Terahertz Quantum Cascade Lasers. IEEE Sensors Journal, 13 (1). 37 -43 . ISSN 1530-437X
Abstract
Terahertz frequency quantum cascade lasers (THz QCLs) are compact sources of coherent THz radiation with potential applications that include astronomy, trace-gas sensing, and security imaging. However, the reliance on slow and incoherent thermal detectors has limited their practical use in THz systems. We demonstrate THz sensing using self-mixing (SM) interferometry, in which radiation is reflected from an object back into the QCL cavity, causing changes in the laser properties; the THz QCL thus acts simultaneously as both a source and detector. Well-established SM theory predicts a much weaker coupling in THz QCLs than in diode lasers, yielding a near-linear relationship between the phase of SM signals and the external cavity length. We demonstrate velocimetry of an oscillating reflector by monitoring SM-induced changes in the QCL drive voltage. We show that this yields data equivalent to that obtained by sensing the emitted THz power, thus allowing phase-sensitive THz-SM sensing without any external detector. We also demonstrate high-resolution SM-imaging at a round-trip distance of 21 m in air #x2014;the longest-range interferometric sensing with a THz QCL to date.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Keywords: | Cavity resonators, imaging, measurement by laser beam, optical attenuators, quantum cascade lasers, sensors, voltage measurement;, infrared sensors, interferometry, laser feedback, laser velocimetry, quantum cascade lasers, submillimeter wave technology |
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: | 24 Jun 2013 12:51 |
Last Modified: | 04 Nov 2016 03:59 |
Published Version: | http://dx.doi.org/10.1109/JSEN.2012.2218594 |
Status: | Published |
Publisher: | IEEE |
Identification Number: | 10.1109/JSEN.2012.2218594 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:74860 |