Multi-diffraction mode liquid crystal grating based on orthogonal alignment method

Over the past few years, liquid crystal (LC) gratings have been extensively used in fields such as 2D/3D compatible and wide-viewing angle color holographic displays. However, LC gratings with parallel alignment method have defects of lower diffraction accuracy and fewer diffraction modes. This paper presents a multi-diffraction mode LC grating, employing an orthogonal alignment technique. The LC grating is composed of a top glass substrate, top pixel and common electrodes, an LC layer, bottom pixel and common electrodes, and a bottom glass substrate. Three different diffraction modes can be achieved by controlling the driving scheme: one-dimensional transverse diffraction effect, one-dimensional longitudinal diffraction effect, and two-dimensional diffraction effect. Simulation results indicate that the LC grating employing the orthogonal alignment technique achieves higher diffraction accuracy compared to the parallel alignment method. Experimental findings further demonstrate that the proposed LC grating features a low operating voltage of 4.0 V and supports multiple diffraction modes. The LC grating has broad application prospects in fields such as 3D display, wide-viewing angle holographic display, and optical communication.