摘要
几何相位的超表面透镜不同于传统折射透镜,相位波前的调制并不依赖于传播过程的累积相位,而是通过空间变化的单元结构改变局域偏振态,引入共轭的附加相位使光束聚焦。为了实现几何相位超透镜变参量结构的干涉制备,提出了空间变参量相位元件调制的傅里叶变换光学系统,利用4f光路的傅里叶变换原理以及相位元件衍射光线的几何传播特性,分析了相位元件空频、取向以及分布区域等对系统成像面光场特性的影响,阐明了空间变参量相位元件分段调制入射光,同时生成多个干涉光场实现变取向、变周期微米结构的制备方法。在此基础之上,利用设计制备的变参量相位元件,生成了圆、环分布下变参量干涉光场,制备了变取向、变周期,半径为1892μm的微米光栅结构,光栅取向为0°,125°,235°,周期分别为7.22,6.51,5.78μm。该系统光路简单,易与投影曝光相集成,为基于空间变参量结构单元的几何相位超透镜的制备提供了一种新的途径。
The modulation of the phase wavefront of geometric phase metasurface lenses does not depend on the cumulative phase of the propagation process.However,it affects the local polarization state through the space-variant unit structure and introduces the conjugate additional phase that focuses the incident beam,which differs from the characteristics of traditional refractive lenses.For interference lithography fabrication of geometric phase metalens structures,an optical Fourier transform system modulated by a space-variant phase element is proposed in this study.Subsequently,the orientation and frequency-variant micron structures were prepared using interference lithography.Based on the Fourier transform theory of optical lens and geometric propagation principle of light diffraction,the influence of light field on image plane based on the inserted sub-phase-elements with different frequencies,orientations,and relative positions was analyzed.Therefore,a method was proposed for multi-interference light fields with sectionalized modulation of space-variant phase elements on incident light.Moreover,the preparation of orientation and period-variant micron structure based on multiple simultaneously generated light fields were illustrated.Accordingly,utilizing the designed and fabricated space-variant phase element,interference light fields with circle and ring distributions were simultaneously generated.The experimental results demonstrate that space-variant grating structures with orientations of 0°,125°,and 235°,periods of 7.22,6.51,and 5.78μm,and micron pattern structure with radius of 1892μm can be obtained simultaneously.The proposed optical system is simple and easy to be combined with a projection exposure system and has great potential for manufacturing geometric phase metalens devices based on a space-variant micro-nano unit cell.
作者
路畅
许峰川
许宜申
陈林森
叶燕
LU Chang;XU Fengchuan;XU Yishen;CHEN Linsen;YE Yan(School of Optoelectronic Science and Engineering,Soochow University,Suzhou 215006,China;Suzhou City University,Suzhou 215104,China;Collaborative Innovation Center of Suzhou Nano Science and Technology,Soochow University,Suzhou 215006,China;Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province&Key Lab of Modern Optical Technologies of Education Ministry of China,Soochow University,Suzhou 215006,China)
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2022年第15期1836-1844,共9页
Optics and Precision Engineering
基金
国家自然科学基金资助项目(No.62075149,No.61575132)
江苏省自然科学基金资助项目(No.BK20201406)
江苏省高校自然科学研究基金资助项目(No.21KJD510003)
江苏省高校优势学科建设(No.PAPD)。
关键词
干涉光刻
4f光学系统
空间变参量
相位调制
interference lithography
4f optical system
space-variant structure
phase modulation
