Quantitative analysis on flyback region problem of 1D transmissive liquid crystal optical phased array devices

In practical application of Liquid crystal optical phased array (LCOPA) device, diffraction efficiency and deflection range are two important performance parameters, which should be improved further more. Both diffraction efficiency and deflection range are directly related to the width of flyback region. Therefore, the flyback region problem was analyzed quantitatively in this paper. According to elastic continuum theory of liquid crystal and crystal optics theory, we calculated LC director and its phase delay profile. Then we analyzed quantitatively the influence of device parameters including electrode size, alignment layer thickness and LC cell thickness on the width of flyback region. Results show that there exists a critical value of electrode size. When electrode size is larger than this critical value, the width of flyback region increases nearly linear to the increase of electrode size. The width of flyback region is not sensitive to alignment layer thickness and increases monotonously with the increase of LC cell thickness.