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arXiv · 1609.06443

Signal line shapes of Fourier transform cavity-enhanced frequency modulation spectroscopy with optical frequency combs

Alexandra C. Johansson·Lucile Rutkowski·Amir Khodabakhsh·Aleksandra Foltynowicz
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Abstract

We present a thorough analysis of the signal line shapes of Fourier transform-based noise-immune cavity-enhanced optical frequency comb spectroscopy (NICE-OFCS). We discuss the signal dependence on the ratio of the modulation frequency, f${_m}$, to the molecular line width, {\Gamma}. We compare a full model of the signals and a simplified absorption-like analytical model that has high accuracy for low f${_m}$/{\Gamma} ratios and is much faster to compute. We verify the theory experimentally by measuring and fitting NICE-OFCS spectra of CO${_2}$ at 1575 nm using a system based on an Er:fiber femtosecond laser and a cavity with a finesse of ~11000.

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Alexandra C. Johansson, Lucile Rutkowski, Amir Khodabakhsh, Aleksandra Foltynowicz. 2016-09-21. Signal line shapes of Fourier transform cavity-enhanced frequency modulation spectroscopy with optical frequency combs. https://doi.org/10.1364/josab.34.000358

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