Three-dimensional terahertz imaging using swept-frequency feedback interferometry with a quantum cascade laser

Abstract

© 2015 Optical Society of America. We demonstrate coherent three-dimensional terahertz imaging by frequency modulation of a quantum cascade laser in a compact and experimentally simple self-mixing scheme. Through this approach, we can realize significantly faster acquisition rates compared to previous schemes employing longitudinal mechanical scanning of asample. We achievea depth resolution of better than 0.1μm witha power noise spectral density below -50 dB/Hz, for asampling time of 10 ms/pixel.