Yu Chang-Jae, Kim Dong-Woo, Kim Jinyool, Lee Sin-Doo
School of Electrical Engineering 032, Seoul National University, Kwanak, P.O. Box 34, Seoul 151-600, South Korea.
Opt Lett. 2005 Aug 1;30(15):1995-7. doi: 10.1364/ol.30.001995.
We demonstrate a polarization-invariant liquid-crystal (LC) grating in an oppositely twisted and mutually orthogonal configuration. The polarization-invariant LC grating with high diffraction efficiency is fabricated using a single-masking process with two-step exposure of a linearly polarized ultraviolet light. It is found that the zeroth- and the first-order diffracted beams are linearly polarized and perpendicular to each other irrespective of the incident polarization for the phase retardation of m pi (m=integer).
我们展示了一种处于反向扭曲且相互正交配置的偏振不变液晶（LC）光栅。采用单掩膜工艺，通过线偏振紫外光的两步曝光制作出了具有高衍射效率的偏振不变LC光栅。研究发现，对于相位延迟为mπ（m为整数）的情况，零阶和一阶衍射光束均为线偏振，且彼此垂直，与入射偏振无关。
