Raman Effect in Semiclassical Theory

Daniel F. Walls

Daniel F. Walls

Vladimir V. Aristov

Eric Heller

Claudio G. Parazzoli, C. Drutman, D. M. Capps

The semiclassical theory of nonresonant stimulated rotational Raman scattering (SRRS) in homonuclear diatomic molecules has been developed. Multiple rotational lines, the full degeneracy of the molecule, Stark shift, and four-wave mixing effects are considered. An arbitrary number of optical fields is allowed. The polarization state of the fields is dynamically computed during the propagation. A numerical code has been written in a user-friendly format based on the theoretical model with diffractive effects included. Numerical results which display the code capabilities are presented and comparisons to available experimental data are shown.>

Jabir Chathanathil, G. Liu, Svetlana Malinovskaya

A semiclassical theory that describes the generation of a coherent anti-Stokes Raman scattering (CARS) signal is presented that maximizes vibrational coherence in a mode predetermined by the pump, the Stokes, and the probe chirped pulse trains and takes into account the field propagation effects in a cloud of molecules. The buildup of the anti-Stokes signal, which may be used as a molecular signature in the backward CARS signal, is demonstrated numerically. The theory is based on the solution of the coupled Maxwell's and Liouville--von Neumann equations and focuses on the quantum effects induced in the target molecules by the control pulse trains. A deep convolutional neural network technique is implemented to evaluate time-dependent phase characteristics of the control fields. The effect of decoherence induced by spontaneous decay and collisional dephasing is examined.