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Coherent, multiheterodyne spectroscopy using stabilized optical frequency combs



Ian R. Coddington, William C. Swann, Nathan R. Newbury


The broadband, coherent nature of narrow-linewidth fiber frequency combs is exploited to measure the full complex spectrum of a molecular gas through multiheterodyne spectroscopy. We measure the absorption and phase shift experienced by each of 155 000 individual frequency-comb lines, spaced by 100 MHz and spanning from 1495 to 1620 nm, after passing through hydrogen cyanide gas. The measured phase spectrum agrees with the Kramers-Kronig transformation of the absorption spectrum. This technique can provide a full complex spectrum rapidly, over wide bandwidths, and with hertz-level accuracy.
Physical Review Letters


Frequency combs, HCN spectrum, precision spectroscopy


Coddington, I. , Swann, W. and Newbury, N. (2008), Coherent, multiheterodyne spectroscopy using stabilized optical frequency combs, Physical Review Letters, [online], (Accessed April 14, 2024)
Created January 1, 2008, Updated October 12, 2021