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arXiv · 1208.1145

Raman-induced Kerr-effect dual-comb spectroscopy

Takuro Ideguchi·Birgitta Bernhardt·Guy Guelachvili·Theodor W. Hänsch·Nathalie Picqué
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Abstract

We report on the first demonstration of nonlinear dual-frequency-comb spectroscopy. In multi-heterodyne femtosecond Raman-induced Kerr-effect spectroscopy, the Raman gain resulting from the coherent excitation of molecular vibrations by a spectrally-narrow pump is imprinted onto the femtosecond laser frequency comb probe spectrum. The birefringence signal induced by the nonlinear interaction of these beams and the sample is heterodyned against a frequency comb local oscillator with a repetition frequency slightly different from that of the comb probe. Such time-domain interference provides multiplex access to the phase and amplitude Raman spectra over a broad spectral bandwidth within a short measurement time. Experimental demonstration, at a spectral resolution of 200 GHz, a measurement time of 293 μs and a sensitivity of 10^-6, is given on liquid samples exhibiting a C-H stretch Raman shift.

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Takuro Ideguchi, Birgitta Bernhardt, Guy Guelachvili, Theodor W. Hänsch, Nathalie Picqué. 2012-08-06. Raman-induced Kerr-effect dual-comb spectroscopy. https://doi.org/10.1364/ol.37.004498

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