Evaluating diffracted light from the liquid crystal phase grating by FDTD method

Abstract

We simulated optical properties of liquid crystal (LC) phase gratings through combining finite difference time domain (FDTD) method and plane wave expansion technique. The LC grating element has the advantage of being electrically, continuously and variably controllable light diffraction. We mathematically expanded the electromagnetic field emitted from the LC cell by the FDTD method to the plane wave spectrum. This technique enables to calculate the diffraction efficiency and the polarization state quantitatively.