Coherent Raman spectroscopy of YBa2Cu3O7

We report preliminary results on the optical driving and spectroscopic detection of Raman-active features in thin films of the high-temperature superconductor YBa2Cu3O7 in its normal phase by means of coherent Stokes and anti-Stokes Raman scattering, in a reflection geometry. Reference measurements on germanium are also reported. We observe phonon resonances which interfere coherently with a broad electronic resonance centered at zero frequency, giving rise to characteristic asymmetric spectral features. Our measurements provide a first step towards applying nonlinear optical wave-mixing spectroscopy to correlated electron systems. (c) 2008 Optical Society of America.