Spectroscopy of the methane Ņ3 Band with an accurate midinfrared coherent dual-comb spectrometer

Published

December 28, 2011

Author(s)

Esther Baumann, Fabrizio R. Giorgetta, William C. Swann, Alexander M. Zolot, Ian R. Coddington, Nathan R. Newbury

Abstract

We demonstrate a high-accuracy dual-comb spectrometer centered at 3.4 υm. The amplitude and phase spectra of the P,, Q, and partial R branches of the methane Ņ3 band are measured at 25 to 100 MHz point spacing with resolution under 10 kHz and a signal-to-noise ratio of up to 3500. A fit of the absorbance and phase spectra yields 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 10-fold improvement over Fourier transform spectroscopy. These data quantify the accuracy and resolution achievable with direct comb spectroscopy in the midinfrared.

Citation

Physical Review Letters

Volume

84

Pub Type

Journals

Keywords

dual comb spectrometer, frequency comb, methane

Citation

Baumann, E. , Giorgetta, F. , Swann, W. , Zolot, A. , Coddington, I. and Newbury, N. (2011), Spectroscopy of the methane Ņ3 Band with an accurate midinfrared coherent dual-comb spectrometer, Physical Review Letters (Accessed October 10, 2025)