Nematic Liquid Crystal Waveguides for Spatial Control of Linearly Polarized Light Waves

Electrically switchable liquid crystal (LC) waveguide structures for spatial-polarization control of light waves become more and more widespread as optical components for waveguide photonics. The motivation of the work was to design and fabricate miniaturized, low-cost electrically switchable LC waveguides for spatial control of linearly polarized light beams. With the use of new configurations of the spatially modulated electric field applied to planar-aligned sandwich-type LC cells $(d=20\mu \mathrm{m}$ thick), the polarization-sensitive waveguide structures performing the functions of optical splitter and adder were designed and experimentally studied. The current-conducting glass substrates coated with patterned electrodes (splitter-shaped and adder-shaped chromium layers) were used to control the optical properties of LC waveguides by applying an external low-frequency (1 kHz) electrical voltage to the LC cell electrodes. The operation principle of the fabricated optical components is based on the effect of total internal reflection (TIR) of laser radiation from the electrically controlled refractive interface between LC areas with orthogonal director orientations. Optical components of this type look promising for the production of competitive low power consumption photonic devices with enhanced functional characteristics.