B. Ya. Zel'dovich

Spin-orbit polarization effects in isotropic multimode fibres

The propagation of an electromagnetic wave in a locally isotropic but smoothly inhomogeneous medium is considered. Both geometric optical and wave optical approaches are used to account for the interaction between propagation and polarization, i.e. spin-orbit interaction of the photon. Starting with the recently derived equations the authors calculate the angular shift of a ray and of an interference pattern which arises as a consequence of the circularity sigma of polarization. The results obtained prove that both the lateral shift of the ray varies as sigma mod Del lambda mod (optical ping-pong effect) and Rytov-Berry-Chiao geometric rotation of polarization are manifestations of the spin-orbit interaction of a photon in an inhomogeneous medium.

High-efficiency energy transfer due to stimulated orientational scattering of light in nematic liquid crystals

The saturation stage of stimulated orientational scattering (SOS) of light in thick planarly aligned nematic-liquid-crystal layers was observed and studied experimentally. The power efficiency of o-wave pump conversion exceeded 90%. Both saturation of transmitted pump power and cascading of SOS were observed. The latter indicated that, for higher than ∼50% conversion efficiencies, inverse conversion of the scattered e-polarized signal into wide-angle speckle, o-polarized background started to take place, leading to partial depletion of the primarily scattered e wave. Results were in good qualitative agreement with conventional SOS theory.

Polarization effects on induced chi (2) tensor properties in bulk glass

The authors explored tensor properties of chi (2) gratings induced in bulk glass under different polarization conditions. Three cases were studied: recording of gratings by waves with parallel, orthogonal and 45 degrees -tilted polarizations. The results obtained point out the presence of a static electric field recorded in proportion to E(EE).

Potential application of Periodically Aligned Liquid Crystal cell for projection displays

Transversely modulated nematic liquid crystal cell is suggested as an element of projection display. Equilibrium of the cell is studied and its optical performance is evaluated. High contrast ratio is predicted

Thermomechanical coupling in a cylindrical hybrid-aligned nematic liquid crystal

A solution to the system of equations describing a cylindrical hybrid-aligned nematic liquid crystal is obtained. The rotational flow driven by vertical temperature gradient in such a cell is investigated theoretically. The cell is suggested as a new experimental setup for determining an additional relation required to measure the twelve thermomechanical coefficients. It is shown that the terms in the expressions for thermomechanical stress and heat flux obtained in [8] are equivalent to those originally proposed in [7].

Bilayer Holograms: Theory and Experiment

Holograms consisting of two thin photolayers separated by a relatively thick optically transparent material (e.g., glass) are investigated experimentally and theoretically. The object fields reconstructed by each layer are superimposed coherently (i.e. in amplitude). Consequently, the diffraction efficiency m increases; m = 50 per cent was experimentally measured for the bilayer hologram of plane waves. It can be increased to 58 per cent by eliminating the Fresnel losses. The experimental diffraction efficiency, angular and spectral selectivity are in good agreement with the theory developed in this paper. The theory predicts that the noise level of the bilayer hologram of speckle fields of the object is less than that of monolayer holograms.

Manifestation of spin-orbit interaction of a photon in a vacuum

The position of a focal spot after transmission of a plane circularly polarized wave (ex+i sigma egamma ) exp(ikz) through the half of a lens ( gamma >0) was investigated. The transverse shift Delta x approximately +or- sigma was found experimentally under switching of the sign of sigma . This effect is considered as the manifestation of spin-orbit interaction of a photon.

An electromagnetic world without polarization

The majority of natural sources (black-bodies, fluorescent bulbs, etc) generate completely un-polarized light; the majority of detectors (eyes, photo-cameras, photomultipliers, etc) are polarization-insensitive. To reflect this, we attempt to describe approximately electromagnetic waves without polarization. Corresponding scalar equations are non-trivial modifications of standard d’Alembert and Helmholtz equations to the case of spatially inhomogeneous propagation speed . A description of Fresnel reflection (FR) and Goos–Hanchen shift for total internal reflection phenomena is given on the basis of these modified equations.

Free-space terminator and coherent broadband blackbody interferometry

We propose a free-space terminator and broadband interferometry based on a coherent blackbody effect in an ultrathin nonreflecting metallic layer in the microwave to infrared domains. A frequency-insensitive device consisting of a metallic layer in a ring (Sagnac) interferometer can be used for autocorrelation measurements of extremely broad EM spectra.

Adiabatic three-wave volume hologram: large efficiency independent of grating strength and polarization

A transmission hologram with two volume gratings is considered in the regime of wave A diffracted into wave B via an intermediate weakly excited wave C. In analogy to the phenomenon of stimulated Raman adiabatic passage in nonlinear optics, this new scheme demonstrates diffraction efficiency with low sensitivity to the holograms strength. A theory of three-wave adiabatic coupling has been developed and explored analytically. Numerical results show an example of a coupling profile that preserves high diffraction efficiency with almost no dependence on the holograms strength, including the suppressed influence of polarization.