基于可调剪切干涉曝光方法的大口径液晶偏振光栅制备  

Fabrication method of large-area polarization grating based on tunable shearing holography

作　　者：沈浩 段佳著 陈一波 乔冉[1] 李大鹏[1] 曾建成[1] 沈志学[1] 赵祥杰[1] 张大勇[1] SHEN Hao;DUAN Jiazhu;CHEN Yibo;QIAO Ran;LI Dapeng;ZENG Jiancheng;SHEN Zhixue;ZHAO Xiangjie;ZHANG Dayong(Institute of Fluid Physics,China Academy of Engineering Physics,Mianyang 621900,China)

机构地区：[1]中国工程物理研究院流体物理研究所,四川绵阳621900

出　　处：《液晶与显示》2024年第5期602-609,共8页Chinese Journal of Liquid Crystals and Displays

基　　金：中国工程物理研究院院长基金(No.YZJJLX2020001)。

摘　　要：为了解决传统偏振全息干涉方法受限于过长的光路难以制备长周期的大口径液晶偏振光栅的问题,提出了基于液晶偏振光栅模板的可调剪切干涉曝光方法,并通过理论分析了制备偏振光栅的周期随模板方位角及沿光轴轴向位置的变化。利用小口径高效液晶偏振光栅作为模板搭建可调剪切干涉曝光光路,并基于此制备了数十微米周期的200 mm口径液晶偏振光栅,平均衍射效率达到99%以上,平均周期约为59.86μm,周期分布不均匀性约为0.07%。实验结果表明,调剪切干涉曝光方法能够制备大口径的长周期偏振光栅,周期和效率分布均匀,还具备周期易于调节、结构紧凑和抗振动干扰强等优势。In conventional dual-beam polarization holography system,the desired polarization profiles of LCPG are accomplished with complicated optics and careful precision alignment,and wherein the relative distances for redirecting beams limit the upper range of periods that can be fabricated.In this paper,we propose a new tunable shearing holography to fabricate large-area LCPGs using small aperture LCPGs as masks.We discuss the grating period dependence on azimuthal rotating angle and position along the optical axis of the grating masks.Using this exposure setup,we demonstrate two long-period PGs where the diameters of the active area are 200 mm.The 200 mm polarization grating exhibits nearly ideal diffraction properties showing over 99%first-order diffraction efficiency.The average grating period is about 59.86μm and the variation is only 0.07%over the entire aperture.The experimental results show that the tunable shearing holography method enables easy fabrication of large-area and arbitrarily longperiod polarization grating with good uniformity.Moreover,the new approach is very compact,much easier to tune the period,more robust to vibration compared with prior polarization holography.

关 键 词：液晶偏振光栅 长周期 可调剪切干涉曝光 大口径 

分 类 号：O753.2[理学—晶体学]