Electrically Controlled 1D and 2D Cholesteric Liquid Crystal Gratings

Electrically induced and controlled gratings in large pitch cholesteric liquid crystals were investigated. Specially selected surface anchoring conditions together with well defined properties of cholesterics allow the formation of a stable periodic structure in the presence of a suitable external electric field. Polarization properties of first diffraction orders have been investigated as a function of the angle between the laser linear polarization and the grating direction. We propose to use two 1D gratings to create a 2D electrically controllable diffraction pattern, suitable for application in 3D optical devices.