Article

Coherent anti-Stokes Raman scattering spectral interferometry: determination of the real and imaginary components of nonlinear susceptibility chi((3)) for vibrational microscopy

Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA.
Optics Letters (Impact Factor: 3.18). 01/2005; 29(24):2923-5. DOI: 10.1364/OL.29.002923
Source: PubMed

ABSTRACT We demonstrate coherent anti-Stokes Raman scattering (CARS) heterodyne spectral interferometry for retrieval of the real and imaginary components of the third-order nonlinear susceptibility (chi(3)) of molecular vibrations. Extraction of the imaginary component of chi(3) allows a straightforward reconstruction of the vibrationally resonant signal that is completely free of the electronic nonresonant background and resembles the spontaneous Raman spectrum. Heterodyne detection offers potential for signal amplification and enhanced sensitivity for CARS microscopy.

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