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

Abstract

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.

Photo- and electro-controllable 2D diffraction gratings prepared using electrohydrodynamic instability in a nematic polymerizable mixture

“…[27][28][29][30][31][32][33][34] It has been repeatedly demonstrated that EHD-induced periodic DGs can also be promising for beam steering applications 28 in various optoelectronic devices, such as tunable spectral filters, polarizing sensors, etc. 29 Recently, a fascinating example of light-driven EHD instabilities was demonstrated by G. Zhou et al 30 The LC mixture with a high negative dielectric anisotropy (De = À8.3) was doped with the spiropyran photochromic substance. Application of an electric field in the absence of UV light induces reorientation of the homeotropically aligned liquid crystal perpendicular to the electrical field direction driven by its negative dielectric anisotropy.…”