Abstract-Methodology for materials analysis using swept-frequency feedback interferometry with terahertz frequency quantum cascade lasers

Thomas Taimre, Karl Bertling, Yah Leng Lim, Paul Dean, Dragan Indjin, and Aleksandar D. Rakić  »View Author Affiliations

Optics Express, Vol. 22, Issue 15, pp. 18633-18647 (2014)

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.

© 2014 Optical Society of America