Open AccessMethodology for materials analysis using swept-frequency feedback interferometry with terahertz frequency quantum cascade lasers
Author(s) -
Thomas Taimre,
Karl Bertling,
Yah Leng Lim,
Paul Dean,
D. Indjin,
Aleksandar D. Rakić
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.018633
Subject(s) - terahertz radiation , optics , cascade , interferometry , laser , quantum cascade laser , photomixing , physics , calibration , far infrared laser , materials science , optoelectronics , chemistry , terahertz metamaterials , chromatography , quantum mechanics
Recently, we demonstrated an interferometric materials analysis scheme at terahertz frequencies based on the self-mixing effect in terahertz quantum cascade lasers. Here, we examine the impact of variations in laser operating parameters, target characteristics, laser-target system properties, and the quality calibration standards on our scheme. We show that our coherent scheme is intrinsically most sensitive to fluctuations in interferometric phase, arising primarily from variations in external cavity length. Moreover we demonstrate that the smallest experimental uncertainties in the determination of extinction coefficients are expected for lossy materials.