Collisional perturbations of time-resolved photon scattering from molecular levels

摘要: A theoretical study is presented of the effects collisional perturbations on time-resolved resonant and near-resonant photon scattering from a molecular system. The counting rate formulated in terms tetradic Green's functions Liouville space. radiative damping are handled by an effective-Liouvillian formalism. formal expressions disentangled invoking series successive approximations, assuming short correlation times thermal bath, neglecting relaxation processes ground electronic state, considering rotational as providing dominant mechanism excited manifold, specializing to weak electromagnetic fields, some off-resonance disregarding collision-induced processes. expressed triple convolution for free molecule with Doppler Gaussian profile Lorentz profile. latter incorporates purely due intrastate cross relaxations proper T$sub 2$ theory accounts well recent experimental data Williams, Rousseau, Dworetsky collisionally perturbed I$sub molecules.