Igor I. Gancheryonok

Polarization spectroscopy with arbitrary polarized noncollinear pumping

We present a theoretical analysis of a noncollinear polarization-spectroscopy (PS) scheme, taking into account the polarization incoherence of an arbitrarily polarized pump beam. It is based on a light-induced anisotropy (LIA) tensor formalism. Our most important results are analytical expressions for the LIA tensor, which permit classification of the nonlinear medium with LIA in terms of the polarization properties. An expression is derived for the dependence of the PS-signal intensity on the beam-crossing angle, and the usefulness of that expression for spectroscopic purposes is demonstrated.

Theory of optically heterodyned polarization (vectorial) interferometry on the basis of Fedorov's covariant approach

We present consistent theoretical studies of optically heterodyned polarization interferometry (OHPI) with noncollinear arbitrary polarized interacting beams in the framework of the cubic nonlinear optical susceptiblity formalism. Our theoretical treatment is based on the covariant tensorial approach introduced by F I Fedorov. We were able to derive the analytical expressions for the detected OHPI signal. Different methods for measuring the nonlinear susceptibility are also suggested.

Free-coordinate formalism for nonlinear photoanisotropy optics description and light propagation effects in periodic anisotropic structures

A theoretical study of two-wave polarization spectroscopy signal dependencies on crossing angle is presented. The quantitative expressions are obtained, which are in good agreement with the experimental data. The advantages of free-coordinate operator method are illustrated under treatment of band-gap formation in anisotropic stratified periodic structure problems. A method for radiation control based on pumping wave polarization tuning is proposed.

Strong-field theory of polarization sensitive spectroscopy

We report new theoretical results on polarization effects within pump-probe scheme of interaction in polarization inhomogeneous media. Our findings are applicable to explanation of experimental data on combustion diagnostics as well as for optimization of polarization geometry conditions under saturation regime.

New peculiarities of spectroscopic measurements with noncollinear scheme and nonpolarized light

We present theoretical analysis of noncollinear two-wave spectroscopic schemes taking into account polarization incoherence of arbitrary polarized pumping. Our very general treatment is based on a coordinate-free method of wave operators. The analytical expressions for the signal dependencies on beam-crossing angle (noncollinearity angle) and polarization parameters have been obtained for the cases of saturation spectroscopy, nonlinear polarization spectroscopy and optically heterodyned polarization interferometry (OHPI). The comprehensive studies of the OHPI scheme with noncollinear partially polarized light are given. Three different methods of nonlinear susceptibility measurements are suggested.

Polarization self-action effects of partially polarized light in polarization inhomogeneous media

On the basis of covariant approach some generalizations of the theory of polarization self-action effects in isotropic (polarization inhomogeneous) resonance media have been done. The results obtained demonstrate influence of the degree of polarization on evolution of polarization parameters of laser radiation propagating in polarization inhomogeneous media. We present new theoretical findings as well as demonstrate agreement between our results and known experimental data.

Output characteristics of isotropic dye lasers under polarized light excitation in the regime of saturation: coaxial pumping

In this paper a theoretical consideration of quasi-steady- state generation of dye lasers (DL) with an isotropic Fabry- Perot-type resonator and coaxial (longitudinal) laser pumping is presented for the regime of saturation in the orientation distribution of excited molecules. Our analysis is carried out for cases of parallel and orthogonal mutual orientation of dipole moments of transitions with absorption and emission in dye molecules. The effect of intensity and polarization state of longitudinal pumping on the degree of linear polarization and output intensity of DL has been clarified. A preference of circular pump polarization occurs in our theory. The comparison of the results obtained with the experimental studies is also performed.

Photon-polarization effects on intermolecular interaction-induced quantum beats in femtosecond time-resolved light scattering from molecular pairs

Abstract It is shown how interaction-induced quantum beats in time-profiles of resonant light scattering from molecular pairs are affected by photon polarizations. We present a method for determining the angle between two local transition-moment vectors of the molecules by measuring the polarization-dependent time-integrated intensity of the scattered light.

Peculiarities of registration of nonlinear photoanisotropy effects in noncollinear geometry of interacting waves

T.he probleni of geometry of puip and probe waves under investigation of nonlinear phctoanisotropy (1ightinthiced birefringence and dichroizi) effects in initially isotropic Ledia are of very importance. However up to now, there are a few papers dedicated to detailed analysis of these questions. 1foreover, a nuniber of peculiarities of registration of effects of anisotropy induced by powerful puLping are unknown yet. This paper solves some of these problem. Using Presnels operator forsalis (1] we succeeded in estimating of influence of finite quantity of convergence angle between probe and pumping wave normals on registered signal intensity in optically heterodyned polarization spectroscopy and nonlinear polarization spectroscopy schemes. In both cases it is shown that noncollinearity of interacting beams influences on the resonance profile form, though this influence can be rather small. In nonlinear photoanisotropy examination scheme [2) , we are the first to find the polarization conditions for correct interpretation of experimental data. Noticeable violal.ion of Kleinman symmetry for cubic susceptibility tensor components of Pluorescein-doped based acid glass is found. This fact is ecplained by the influence of thermal gratings induced in the medium by nonparallel probe and pumping waves. It is particularly actual in frequency degenerated case. The theoretical analysis of reflection scheme for studying light-S induced anisotropy is also presented. It opens new perspectives under investigation of nonlinear photoanisotropy phenomena.

Polarization spectroscopy: theory beyond assumption of colliniarity of interacting waves

Abstract The theoretical analysis of two-wave scheme of polarization spectroscopy with noncollinear geometry of interacting waves is given. Some advantages and new possibilities of several polarization variants of nonlinear polarization sensitive spectroscopy have been found. The theoretical results are supported by the experimental data for triphenylmethane dye in mixed solvent of water and ethylene glycol.