Waveguide light propagation in electrically controlled Liquid-Crystal elements
Belarusian State University, Belarus
Nowadays liquid crystals are the object of attention of scientists. The high value of the optical anisotropy and the ability to control it in thin-film LC elements using low voltages are the causes of widespread using of LC in modern optoelectronic devices, which perform the possibility of processing and transmission of quantum-optical signals. The aim of the present work is to realize waveguide propagation of laser radiation in the LC structures, which were created on the basis of the developed methods and technologies for electrically-driven LC elements with different topologies modulation on the border of mesophases. In this work two ways to create electrically controlled waveguide LC structures were developed: the method of mechanical rubbing of the alignment layer, the method of photoorientation. In the first case, the modulation of anisotropy of refractive index was induced by external electric field. In the second case, it was induced due to the initial planar perpendicular orientation of the LC director in related areas. The principle of operation in such devices is based on the phenomenon of total internal reflection of linearly polarized light from electrically controlled border between two regions with different topologies LC director orientation. So, on the basis of liquid crystal elements with electrically controlled topology of director orientation waveguide propagation and control of the light beam in space can be realized.