Speaker
Sandro Dal Cin
(TU Wien)
Description
Dual comb spectroscopy using Quantum Cascade Laser (QCL) frequency combs, is a widely applied technique for identification of optical absorption features in the radio-frequency (RF) domain. Temperature fluctuations and electronic noise lead to often highly unstable heterodyne beating signals, hindering reproducible evaluation and analysis. We present a simple, yet reliable phase locking technique based on a dual feedback Optical Phase Locked Loop (OPLL), enabling locking bandwidths above 600 kHz for a heterodyne QCL frequency comb setup. A simplified theoretical model is applied to estimate the required parameters for the loop filters relying on a single measurement of the frequency modulation sensitivity of one frequency comb.
Primary author
Sandro Dal Cin
(TU Wien)
Co-authors
Johannes Hillbrand
(ETH Zürich)
Gottfried Strasser
(TU Wien)
Benedikt Schwarz
(TU Wien)
