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arXiv · 1110.1401

Spectroscopy of the Methane ν3 Band with an Accurate Mid-Infrared Coherent Dual- Comb Spectrometer

E. Baumann·F. R. Giorgetta·W. C. Swann·A. M. Zolot·I. Coddington·N. R. Newbury
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Abstract

We demonstrate a high-accuracy dual-comb spectrometer centered at 3.4 μm. The amplitude and phase spectra of the P, Q, and partial R-branch of the methane ν3 band are measured at 25 MHz to 100 MHz point spacing with ~kHz resolution and a signal-to-noise ratio of up to 3500. A fit of the absorbance and phase spectra yield the center frequency of 132 rovibrational lines. The systematic uncertainty is estimated to be 300 kHz, which is 10-3 of the Doppler width and a tenfold improvement over Fourier transform spectroscopy. These data are the first high- accuracy molecular spectra obtained with a direct comb spectrometer.

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E. Baumann, F. R. Giorgetta, W. C. Swann, A. M. Zolot, I. Coddington, N. R. Newbury. 2011-10-06. Spectroscopy of the Methane ν3 Band with an Accurate Mid-Infrared Coherent Dual- Comb Spectrometer. https://doi.org/10.1103/physreva.84.062513

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