Terahertz imaging through self-mixing in a quantum cascade laser

School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT, UK.
Optics Letters (Impact Factor: 3.29). 07/2011; 36(13):2587-9. DOI: 10.1364/OL.36.002587
Source: PubMed


We demonstrate terahertz (THz) frequency imaging using a single quantum cascade laser (QCL) device for both generation and sensing of THz radiation. Detection is achieved by utilizing the effect of self-mixing in the THz QCL, and, specifically, by monitoring perturbations to the voltage across the QCL, induced by light reflected from an external object back into the laser cavity. Self-mixing imaging offers high sensitivity, a potentially fast response, and a simple, compact optical design, and we show that it can be used to obtain high-resolution reflection images of exemplar structures.

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    • "Examples are systems with a liquidhelium-cooled bolometer [13], a Golay cell [14], a pyroelectric detector [15], a Schottky diode [16], or a Si-bolometer [17]. Recently, self-mixing in the QCL was used for THz reflection imaging [18]. Besides two-dimensional (2-D) imaging, threedimensional (3-D) imaging by CT has also been demonstrated with a QCL [14]. "
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