Efficiency of diffraction gratings based on liquid crystals

Abstract

Wehave recorded geometric-phase diffraction gratingusing the method of holography on a thin layer of dichroic dye. A transmission liquid crystal cell hasbeen assembled inorder to obtain electrically-controlled diffraction in visible range. Also, using software for electrooptical effects modeling wehavecalculated the diffraction efficiency (DE) of the LC-based phase grating as a function of the voltage amplitude at the electrodes,es-timatedtheDEvariation as a function of LCcell thickness, LC materialbirefringenceand the radiation wavelength. The experimental data qualitatively matched with calcu-lation results. 1-st order DE of16% (at 532 nm) has been obtainedforsingle-sided phase grating LC. Furthermore, we have observed the decrease ofDEwith the increase of radiation wavelength.