Optical modes of multilayered photonic structure containing nematic layer with abnormal electroconvective rolls

Optical modes of a multilayered photonic structure with the twisted nematic liquid crystal as a defect layer have been investigated. The electroconvective flow in the nematic makes a spatially periodic structure in the form of abnormal rolls. Non-adiabatic propagation of polarized light in the defect layer causes unique features of the optical modes corresponding to the ordinary $o$-waves. The decay of these modes has been demonstrated with increasing voltage due to the effect of cross-polarization diffraction loss. The modes short-wave shift resulting from the contribution of the non-adiabatic geometric phase to the total phase delay of the wave during a round-trip propagation through the photonic structure has been found both experimentally and numerically