采用丙烯酸酯双单体的高空间频率透射式体全息H-PDLC光栅的研制  

Preparation of dual-monomer high spatial frequency H-PDLC grating based on acrylic polymer

作　　者：朱宁 郑继红[1] 申桐 李科 刘悠嵘 ZHU Ning;ZHENG Jihong;SHEN Tong;LI Ke;LIU Yourong(School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学光电信息与计算机工程学院,上海200093

出　　处：《液晶与显示》2024年第6期752-760,共9页Chinese Journal of Liquid Crystals and Displays

基　　金：科技部重点研发计划(No.2018YFA0701802);国家自然科学基金(No.61975122)。

摘　　要：全息聚合物分散液晶(holographic-polymer dispersed liquid crystal, H-PDLC)体全息光栅因其化学状态稳定、制作简单、价格低廉等优势为全息光波导耦合器件提供了一个更优的思路。本文提出了采用复合型丙烯酸酯类高/低折射率匹配调制的H-PDLC透射式体光栅的研制。首先结合耦合波理论及分子扩散理论介绍了H-PDLC光栅的形成机理。然后,通过实验对不同官能度单体的光栅材料进行筛选,并研究其全息衍射特性。在此基础上,进一步采用提高引发剂含量的方式优化了高频体全息H-PDLC光栅性能。实验结果表明,该双单体的H-PDLC配方可实现在可见光波段透过率大于90%,在空间频率为973 lp/mm下,衍射效率达到90%,响应带宽为99 nm;在2 941 lp/mm下,衍射效率为75.4%,响应带宽为29 nm。该H-PDLC光栅作为波导显示系统的耦合器件有可观的应用前景。Holographic-polymer dispersed liquid crystal(H-PDLC)volume holographic gratings provide a better approach for holographic waveguide couplers due to stable chemical state,simple fabrication and low cost advantages.This article proposes the development of H-PDLC transmissive volume gratings using composite acrylic high/low refractive index matching modulation.Firstly,the formation mechanism of H-PDLC grating was introduced based on the combination of coupled wave theory and molecular diffusion theory.Then,grating materials with different functional monomers were screened through experiments,and holographic diffraction properties were studied.On this basis,the performance of highfrequency volume holographic H-PDLC gratings was further optimized by increasing the content of initiators.The experimental results show that the H-PDLC formulation of this dual monomer can achieve a visible light transmittance of over 90%,with a diffraction efficiency of 90%and a response bandwidth of 99 nm at 973 lp/mm;At 2941 lp/mm,the diffraction efficiency is 75.4%and the response bandwidth is 29 nm.The H-PDLC grating has considerable application prospects as a coupler in waveguide display systems.

关 键 词：聚合物分散液晶 透射式体全息光栅 衍射效率 波长响应带宽 

分 类 号：O753.2[理学—晶体学] O436[机械工程—光学工程]