基于光流控的动态可重构手性液晶宽带反射型几何相位研究

调控相位、振幅或偏振而产生的复杂空间结构光场在工业、通讯、生物医疗、天文观测和国防军事等领域具有广泛应用前景，一直是现代光学领域的研究热点。顺应小型化、集成化、多功能化等趋势，迅速发展的液晶几何相位提供了新颖的实现方案。面向进一步拓展动态可重构方式的需求，本项目基于光流控器件中液体成分的可选择性，研究一类具有原创性的手性液晶宽带反射型几何相位光学元件。无需满足任何相位差条件，可以工作在较宽的反射波长范围，并覆盖整个0-2π相位，且具有同等高效率。通过控制微通道内互溶液体之间的相互扩散过程，对集成于微通道内的由光取向与光聚合得到的图案化胆甾相液晶模板进行可逆填充，调控工作波长、相位、强度、偏振、转化效率等光学特性。提出的微通道集成方法具有可移植性与兼容性，将激活自适应、多功能平面光学元件的全新设计，加深对光控软物质畴工程的认识，有望给基础科学和应用技术两方面都带来重要进步。

The complex structured light field generated by the modulation of phase, amplitude or polarization has a wide range of applications in industry, communication, biomedicine, astronomical observation, national defense and other fields, and has been a research focus in modern optics. Following the trend of miniaturization, integration and multi-function, the rapidly developing geometric phase based on liquid crystal (LC) materials provides an innovative implementation solution. In order to further explore dynamically reconfigurable methods, an original type of chiral LC broadband reflective geometric phase optical elements is studied in this project, based on the selectivity of liquid components in optofluidic devices. The devices can be operated in a wide-band reflection mode, and cover the phase with a range from 0 to 2π with equal efficiencies without satisfying any phase difference condition. By controlling the diffusion process between the mutually soluble liquids in the microchannel, the optical properties, such as wavelength, phase, intensity, polarization and conversion efficiency can be regulated by the reversible filling of patterned cholesteric LC (CLC) polymer templates fabricated by photoalignment and photopolymerization. The method of micro-channel integration proposed in this project is portable and compatible. The innovatively designed optical elements, which has the advantages of self-adaption and multi-function, will deepen the understanding of the light-controlled domain engineering of soft materials, and is expected to bring important progress both in basic science and applied technology.