Synchronously controlled optical modes in the transmittance and reflectance spectra of multilayer photonic structure with dual-frequency nematic liquid crystal.

A method for electrically controlled synchronous mode tuning in the transmittance and reflectance spectra of a photonic structure consisting of an asymmetric dielectric Fabry-Pérot microcavity and an ultrathin metallic film has been proposed. The excitation of a broadband Tamm plasmon polariton at a metal/Bragg mirror interface is accompanied by the two phenomena opposing one another. Due to the strong absorption induced by the metal, a sufficient rejection level in the reflection of the off-resonant radiation has been obtained in a wide spectral range, which almost coincides with the photonic band gap, while at the cavity mode frequencies the structure becomes transparent for the reflected radiation.

Ghost image restoring using random speckles created by a liquid crystal cell.

A liquid crystal cell is used to produce correlated light beams with speckle structures for implementation of pseudo-thermal ghost imaging. The liquid crystal cell makes it possible to provide random spatial intensity distributions, which are characterized by a low coefficient of mutual cross correlations. Ghost imaging of an object representing an amplitude mask is demonstrated.

Electrically induced transformations of defects in cholesteric layer with tangential-conical boundary conditions.

Electric-field-induced changes of the orientational structures of cholesteric liquid crystal layer with the tangential-conical boundary conditions have been investigated. The samples with the ratio of the cholesteric layer thickness d to the helix pitch p equalled to 0.57 have been considered.

Geometric phase and o-mode blueshift in a chiral anisotropic medium inside a Fabry-Pérot cavity.

Anomalous spectral shift of transmission peaks is observed in a Fabry-Pérot cavity filled with a chiral anisotropic medium. The effective refractive index value resides out of the interval between the ordinary and the extraordinary refractive indices. The spectral shift is explained by contribution of a geometric phase.