A brief review is given of topics relating to dynamical processes arising in nonlinear interactions between light and resonant systems (atoms or molecules) in the presence of a magnetic field.

http://blogi.lu.lv/mauzins/files/2010/02/Alexandrov_05.pdf

Dynamic effects in nonlinear magneto-optics of atoms and molecules: review

This chapter intends to aid in the process of building bridges between the stationary state and wavepacket communities. It also takes a tentative first step into the area explicitly prohibited by the title of this book, the dynamics of polyatomic molecules. A central justification for a book dedicated to the spectra and dynamics of diatomic molecules is that all of the concepts, models, and analysis tools developed for diatomic molecules are applicable to polyatomic molecules. The strong- and weak-coupling limits of the two-state quantum beat problem are discussed. A short excitation pulse creates a coherent superposition of several nondegenerate eigenstates or quasi-eigenstates (that is, decaying states described in the complex energy formalism). As the eigenstates coherently excited by an excitation pulse at t = 0 do not have the same energy, the wavefunction ψ(t) for each molecule evolves after the excitation pulse in a manner determined by the pulsed molecule↔radiation field interaction.

Chapter 9 – Dynamics

This review deals with molecular high-resolution spectroscopy based on the quantum beat phenomenon. Applications of the essentially Doppler-free quantum beat technique are presented with special emphasis on the theoretical description. After an historical introduction and a general discussion of interference experiments, we discuss the expressions to describe the time-resolved fluorescence of a molecule following well defined laser excitation. Our general treatment for the characterization of the excited superposition state enables us to demonstrate the versatility of the method by identifying the excited molecular eigenstates with, for example, Zeeman levels or fine- and hyperfine-structure levels. In addition to the spectroscopic applications of quantum beat experiments in determining molecular structure parameters, we address the applications to molecular dynamics and statistical properties of molecular level structures.

Quantum beat spectroscopy of molecules

A simple method of observing coherent ground state transients

Molecular quantum beat spectroscopy

A novel technique is described for high-resolution spectroscopy. The time evolution of a coherent superposition of atomic substates created by a short resonant laser pulse is monitored via changes in polarization of a delayed probe pulse due to stimulated emission. As a demonstration the method was applied to the Zeeman splitting of the $6^{3}P_{1}$ state of ytterbium.

W. Lange

Papers

Quantum Beats in Transmission by Time-Resolved Polarization Spectroscopy