title: Femtosecond stimulated Raman scattering for polyatomics with harmonic potentials: application to rhodamine 6G.
abstract: The perturbation theory of stimulated Raman scattering (SRS), with Raman pump on minus pump off and heterodyne detection along the probe direction, is reviewed. It has four third-order polarization terms, labeled as SRS or inverse Raman scattering (IRS): SRS(I), SRS(II), IRS(I), and IRS(II). These four polarizations have a wave packet interpretation. The polarizations, with homogenous and inhomogeneous broadening included, can be written as integrals over four-time correlation functions, and analytic formulas are derived for the latter for multidimensional harmonic potential surfaces with Franck-Condon displacements in the modes which facilitates the calculation of the SRS cross sections. The theory is applied to understand recent experimental results on the femtosecond SRS (FSRS) of a fluorescent dye, rhodamine 6G (R6G), where the Raman pump pulse is about 1 ps long, and the probe pulse is about 10 fs. The calculations compared very well with the R6G experimental results for off-resonance and resonance FSRS spectra spanning both Stokes and anti-Stokes bands, and for negative and positive pump-probe delay times on resonance.
authors: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors: Kai
authors: K
authors: Niu
authors: Shulin
authors: S
authors: Cong
authors: Soo-Y
authors: SY
authors: Lee
mesh_terms: D000042:Absorption; D005456:Fluorescent Dyes / Q000737:chemistry*; D005583:Fourier Analysis; D012235:Rhodamines / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013997:Time Factors
chemical_list: D005456:Fluorescent Dyes; D012235:Rhodamines; C026188:rhodamine 6G