Background-free coherent Raman spectroscopy by detecting the spectral phase of molecular vibrations

摘要

We propose and demonstrate a new approach to subtracting high nonresonant background in coherent anti-nStokes Raman scattering spectroscopy. The method is based on the retrieval of the spectral phase of mo-nlecular vibrations using the technique of frequency-resolved optical gating of Raman scattering. In the pres-nence of high nonresonant background the retrieved phase corresponds directly to the background-freenspectrum of the coherent Raman response. © 2008 Optical Society of American.