径向偏振光二值相位型宽带远场超分辨聚焦器件设计  

Binary Phase Broadband Far-field Super-resolution Focusing Device with Radially Polarized Wave

作　　者：祝捷贤 熊亮[1,2] 孔锤锐[2,3] 邓琥 武志翔[1,2] ZHU Jiexian;XIONG Liang;KONG Chuirui;DENG Hu;WU Zhixiang(School of Information Engineering,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;Joint Laboratory for Extreme Conditions Matter Properties,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;School of Manufacturing Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China)

机构地区：[1]西南科技大学信息工程学院,四川绵阳621010 [2]西南科技大学极端条件物质特性实验室,四川绵阳621010 [3]西南科技大学制造科学与工程学院,四川绵阳6210100

出　　处：《西南科技大学学报》2023年第3期75-81,共7页Journal of Southwest University of Science and Technology

基　　金：国家自然科学基金(62105271);四川省科技厅支撑计划(2020YJ0160);西安近代化工研究所开放基金(SYJJ20210411);西南科技大学博士基金(19zx7160)。

摘　　要：为克服传统透镜体积大、难以集成化的不足,针对入射波长λ=2500μm的径向偏振光,基于光学超振荡原理设计了透镜半径为20λ、聚焦焦距为5λ、数值孔径NA=0.97的二值相位型宽带太赫兹远场超分辨聚焦器件。仿真结果表明:该远场太赫兹聚焦透镜在λ=2500μm时,在焦平面形成有效聚焦焦点,该焦点半高全宽为0.445λ(1112.5μm),小于阿贝衍射极限(0.5λ/NA=0.518λ),旁瓣比为15.9%,实现了远场超分辨聚焦;设计的透镜在2100~2900μm波长范围内可形成亚波长聚焦焦点,且在2300~2900μm波长范围内能够实现远场超分辨聚焦。相较于传统光学超分辨技术存在的工作距离短、集成困难、带宽较小等问题,该平面透镜设计灵活,具有物理尺寸小、工作距离适中、带宽范围大等优点,可广泛用于集成化的光学系统中。In order to overcome the disadvantages of large size and difficult integration of traditional lens,a binary phase broadband terahertz far-field super-resolution focusing lens with a radius of 20λ,a focal length of 5λand a numerical aperture NA=0.97 was designed based on the principle of optical super-oscillation for radially polarized light with incident wavelength of 2500μm.Simulation results show that whenλ=2500μm,the effective focal spot is formed in the focal plane.The half-height full width of the focal spot is 0.445λ(1112.5μm),which is less than the Abbe diffraction limit(0.5λ/NA=0.518λ),and the side lobe ratio is 15.9%.The designed lens can form subwavelength focusing focus in the wavelength range of 2100-2900μm,and more importantly,it can achieve far-field super-resolution focusing in the wavelength range of 2300-2900μm.Compared with the problems of the traditional optical super-resolution technology,such as short working distance,difficult integration and small bandwidth,the planar lens has the advantages of flexible design,small physical size,moderate working distance and wide bandwidth range,which can be widely used in integrated optical systems.

关 键 词：远场超分辨聚焦 径向偏振光 平面透镜 宽带 

分 类 号：TN761[电子电信—电路与系统] O441.4[理学—电磁学]