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Spectroscopy with a coherent dual frequency comb interferometer at 3.4 µm
Published
Author(s)
Esther Baumann, Fabrizio R. Giorgetta, Ian R. Coddington, William C. Swann, Nathan R. Newbury
Abstract
A coherent dual fiber-comb spectrometer centered at 1.5 µm wavelengths is transferred to 3.4 µm by difference-frequency generation with a 1064 nm cw laser. It is shown that the residual linewidth between the comb teeth at 3.4 µm is resolution-limited to 200 mHz; such narrow linewidths can enable coherent dual-comb spectroscopy at high-precision and signal-to-noise ratio. We then discuss different interferometric configurations for coherent dual-comb spectroscopy. We find that a two branch interferometric setup is appropriate to measure both the magnitude and phase spectrum of purely Doppler broadened absorption lines. An initial measurement of methane lines in the nu3 band P-branch with a resolution of 114 MHz is demonstrated.
Proceedings Title
SPIE Optical Engineering + Applications:Interferometry XV: Techniques and Analysis
Baumann, E.
, Giorgetta, F.
, Coddington, I.
, Swann, W.
and Newbury, N.
(2010),
Spectroscopy with a coherent dual frequency comb interferometer at 3.4 µm, SPIE Optical Engineering + Applications:Interferometry XV: Techniques and Analysis, San Diego, CA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=905917
(Accessed October 14, 2025)