Optical anisotropy induced by torsion stresses in LiNbO3 crystals: appearance of an optical vortex

We report the results of studies of torsion effect on the optical birefringence in LiNbO3 crystals. We have found that twisting of those crystals causes a birefringence distribution revealing non-trivial peculiarities. In particular, it has a special point at the center of cross section perpendicular to the torsion axis where zero birefringence value occurs. It has also been ascertained that the surface of the spatial birefringence distribution has a conical shape, with the cone axis coinciding with the torsion axis. We have revealed that an optical vortex, with the topological charge equal to unity, appears under the torsion of LiNbO3 crystals. It has been shown that, contrary to the q-plate, both the efficiency of spin-orbital coupling and the orbital momentum of the emergent light can be operated by the torque moment.Comment: 28 pages, 8 figure

Maxwell Equations with Accounting of Tensor Properties of Time

The Maxwell equations with accounting for tensors properties of time have been considered. The effects that follow from such consideration are described. These are the appearance of vacuum polarization, anisotropy of electromagnetic wave velocity in vacuum, anisotropy of the vacuum dielectric permittivity, rotation of light polarization plane, as well as the existence of longitudinal components of electromagnetic wave and the rotational (non-potential) component of electric field caused by electric charges.Comment: 13 page

On the problem of phase transitions in lysozyme crystals

We present experimental evidence of the fact that lysozyme crystals, which are grown from their mother solution and exist in it, dissolve on heating above T=307 K. We argue that the anomaly in the light scattering recently observed at the temperature T=307 K and identified in the reference [Svanidze A. V. et al. 2006. JETP Lett. 84: 551] as a structural crystalline phase transition in the single lysozyme crystals, in fact, corresponds to a temperature limit of the crystal existence.Comment: 6 pages, 1 figur