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International audienceWe take advantage of the Raman soliton self-frequency shift experienced during the propagation in an anomalous dispersive photonic crystal fiber in order to continuously tune the central frequency of ultrashort pulses. We discuss the fiber properties to be favored to obtain high power spectral densities and we carry out an extensive experimental study of the properties of the frequency shifted pulses in terms of spectral, autocorrelation, and RF spectrum measurements

We perform multiplex coherent anti-Stokes Raman scattering (CARS) micro-spectroscopy with a picosecond pulsed laser and a broadband supercontinuum (SC) generated in photonic crystal fiber. CARS signal stability is achieved using an active fiber coupler that avoids thermal and mechanical drifts. We obtain multiplex CARS spectra for test liquids in the 600-2000 cm(-1) spectral range. In addition we investigate the polarization dependence of the CARS spectra when rotating the pump beam linear polarization state relative to the linearly polarized broad stokes SC. From these polarization measurements we deduce the Raman depolarization ratio, the resonant versus nonresonant contribution, the Raman resonance frequency, and the linewidth.

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