Self-induced resonant optical rotation in crystals KCl:Li

The specific rotation of the resonant radiation polarization plane predicted earlier for cubic crystals with tunneling centers is observed in KCl containing F_A(Li) centers. The rotation is supposed to be connected essentially with the well-known off-center position of Li⁺ ion. The simple theory based on this assumption agrees with the experimental data.     

Natural optical activity and liquid crystals

Optical activity of matter is related to the chirality of its constitutive molecules. In liquid crystals, chiral molecules can give rise to superstructures in which the local dielectric tensor rotates in space describing a helix, a fact which greatly enhances the optical activity of the medium. The structures and the optical properties of some helical phases are well-known, as for instance the cholesteric and some chiral smectic phases. For short enough helix pitches, the periodic medium can be considered optically as homogeneous and described by the same constitutive equations used to define the optical properties of solid crystals. Such liquid crystal phases represent an ideal tool to apply the methods, used since a long time in optics, to define homogeneous models for non homogeneous media and to discuss their limits of validity. A brief account is given of the main results recently found in this research area.     

Self-induced nonlinear spin-orbit interaction of light in liquid crystals

We report on the observation of self-induced nonlinear spin-orbit interaction of light driven by Kerr orientational optical nonlinearities in liquid crystals. It consists of the self-induced spin-to-orbital nonlinear conversion for the angular momentum of light. The optical angular momentum conversion is driven by the creation of a topological liquid crystal defect by the light itself. Moreover, we show that such a nonlinear process can be significantly enhanced by using additional electric fields.     

Dispersion of optical activity in lithium iodate crystals

Recently LiIO₃ crystals have come to be used in nonlinear optics for frequency doubling of lasers [1]. Their use in parametric light oscillators and in electro-optical modulators is likewise promising.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 15, No. 2, pp. 308–309, February, 1972.     

Self-induced transparency of very short optical pulses

Solutions to a first order wave equation, appropriate to ultrashort optical pulse theory and to the optical undamped Bloch equations are presented. Detuning is shown to play essential role in the physical interpretation of these solutions. Related cases have been discussed by Courtens and by Lee. It is noted that the rotating wave approximation introduces strong restrictions on the range of validity of possible solutions. Pulses with Lorentzian shapes, while implied by the equations, appear to be without physical significance.     

On the origin of optical activity in inorganic crystals

In inorganic crystals, the origin for optical activity is associated with bended bonds created by vacancies. The bended pattern of charge distribution creates a situation where electric and magnetic dipole moments have parallel components and hence, their contribution is more significant than the one derived from atomic polarizability. Numerical calculations have been carried out for a quartz crystal and the results are in agreement with experimental data.     

Intensity dependence of thermal nonlinear optical activity in crystals

The thermal contribution to nonlinear optical activity in a BSO crystal was studied at 514.5 nm. The results show that the effect is only weakly dependent on laser intensity for constant beam power. By varying the laser spot size in the sample the electronic and thermal contributions to nonlinear optical activity may be separated.     

Self-induced thermal effects of optical pulses in model aerosol media

The self-broadening and intensity self-limiting of millisecond optical pulses in the nonlinear scattering of intense light in model aerosol media are investigated experimentally. The experimental results are compared with existing theoretical calculations.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 33–39, March, 1976.     

Birefringence and optical activity of CuAlSe2 single crystals

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 56, No. 1, pp. 81–85, January, 1992.     

Influence of the optical activity on hologram formation in photorefractive crystals

It is shown that dynamical hologram formation in photorefractive, optically active crystals is accompanied by polarization and energy exchange. These effects may be used like new effective holographic methods for determinations of crystal parameters and optical signal processing in real time. In self-diffraction a polarization rotation the order of degrees/cm for Bi₁₂TiO₂₀ and Bi₁₂SiO₂₀ is predicted.     

Self-induced phase matching in stimulated four-wave mixing in a nonbirefringent single-mode optical fiber

Self-induced phase matching in stimulated four-wave mixing in a nonbirefringent single-mode optical fiber has been observed. It is shown that in a nonbirefringent single-mode fiber the phase matching that is necessary for stimulated four-wave mixing can be accomplished with a combination of self-phase modulation and cross-phase modulation induced by a pump-laser pulse.     

Theory of the influence of optical activity on Raman effect in crystals

The theory of the “banding” of Raman lines observed in optically active crystals has been fully worked for the different classes of Raman lines. In the case of cubic crystals the Raman lines belonging toE andF classes can exhibit “normal” “reverse” or any intermediate type of banding depending on the crystal orientation, and further the perfection of the banding can vary forE lines. The crystal axes and the sign of optical activity of a cubic crystal can be deduced from Raman effect studies.