Line shapes for low frequency depolarized (VH) light scattering from fluids. Coupling of rotational and translational motion

Abstract

A generalized theory for depolarized (VH) light scattering from fluids of nonspherical rigid molecules at low frequencies is presented. The dispersion equation for the part of the spectrum which can have fine structures (the autocorrelation function of α_{k x z}) is reduced to a simple quadratic equation given the condition that the internal angular momentum of the molecules decays much faster than the anisotropic polarizability and the transverse linear momentum. The solutions of the quadratic equation and the spectrum of the autocorrelation function of α_{k x z} are similar to those of a linear damped harmonic oscillator. Thus, the depolarized spectrum has different line shapes depending on the experimental situation (e.g., temperature, wave vector, etc.).