@inproceedings{6ead5c966b264a24a6a89d4fdef768d5,
title = "Comb tooth resolved MIR spectroscopy using a VECSEL frequency comb and a virtually-imaged phased array spectrometer",
abstract = "Mid infrared frequency combs allow for high resolution absorption spectroscopy of molecular species, which have strong signatures in this spectral region. Dual comb spectroscopy can provide broadband and high-resolution capability, but requires two fully stabilized frequency combs which adds complexity to the system. Previous work has demonstrated that frequency combs coupled with a high resolution spectrometer, consisting of a virtually imaged phased array (VIPA) along with a grating, can perform time-resolved, broadband and high- resolution absorption spectroscopy with a single frequency comb. The VIPA spectrometer disperses the spectrum in two dimensions and images it onto a focal plane detector array. If the comb teeth can be resolved, the VIPA is easily calibrated and provides comb-tooth resolved resolution and accuracy. However, in previous work, the repetition rate of the laser sources used was too low to be resolved directly, and additional passive {"}filter cavities{"} had to be employed to increase the effective repetition rate of the frequency comb. In this work we use a fully stabilized mid infrared frequency comb based on a 1.6 GHz repetition rate modelocked vertical external cavity surface emitting laser (VECSEL) and difference frequency generation to produce an off set free comb in the 3- 4 micron wavelength range. The source is directly coupled to the VIPA spectrometer to provide comb-tooth resolved absorption spectroscopy. We discuss the system's performance in gas absorption spectroscopy and its time resolving capabilities, which are limited only by the speed of the detector system.",
keywords = "Difference frequency generation, Frequency comb, GHz, Methane, Mid-infrared, Spectroscopy, VECSEL, VIPA",
author = "Robert Rockmore and Ricky Gibson and Jones, {R. Jason} and Moloney, {Jerome V.}",
year = "2020",
doi = "10.1117/12.2546752",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Hastie, {Jennifer E.}",
booktitle = "Vertical External Cavity Surface Emitting Lasers (VECSELs) X",
note = "Vertical External Cavity Surface Emitting Lasers (VECSELs) X 2020 ; Conference date: 04-02-2020 Through 05-02-2020",
}