超分辨波长调控变焦超透镜  

Super-Resolution Wavelength-Controlled Zoom Metalens

作　　者：黄宝泽 赵芬 刘钦晓 杨俊波[2] Huang Baoze;Zhao Fen;Liu Qinxiao;Yang Junbo(School of Artificial Intelligence,Chongqing University of Technology,Chongqing 401135,China;Center of Material Science,College of Science,National University of Defense Technology,Changsha 410073,Hunan,China)

机构地区：[1]重庆理工大学两江人工智能学院,重庆401135 [2]国防科技大学理学院物质与材料科学实验中心,湖南长沙410073

出　　处：《光学学报》2023年第23期241-252,共12页Acta Optica Sinica

基　　金：国家重点研发计划(2022YFF0706005);国家自然科学基金(12272407,60907003,61805278,62275269,62275271);重庆理工大学引进人才科研启动项目(0121210528)。

摘　　要：提出了一种超分辨波长调控变焦超透镜的设计方法,同时对相位、色散、振幅进行调控,在提升超透镜轴向变焦能力的基础上,采用分层粒子群优化(HPSO)算法不断压缩超透镜的点扩散函数,使超透镜的半峰全宽(FWHM)不断逼近甚至小于衍射极限0.5λ/NA(NA为数值孔径)。作为理论验证,设计了一种工作在68~80μm波长范围内的超分辨波长调控变焦超透镜。仿真结果表明,其轴向变焦能力约为常规衍射超透镜的1.52倍,在73~78μm波长范围内的横向分辨率小于衍射极限。Objective Chromatic aberration caused by dispersion usually degrades the system imaging quality in optical imaging systems.Therefore,a large number of researchers have used various methods to correct chromatic aberration in devices and systems.However,chromatic aberration is of practical value in certain specific areas,such as wavelength-controlled optical zoom by chromatic aberration,so that mechanical moving parts are no longer required in zoom systems with fast,continuous,and repeatable zoom by only changing the incident wavelength.It effectively improves the detection efficiency of optical systems and promotes the development of optical zoom systems in the direction of integration and miniaturization.Optical metasurfaces have powerful multi-dimensional light field modulation capabilities.Metasurface planar lenses,namely metalenses,are realized based on the local abrupt phase introduced by sub-wavelength structures,which allow complex and bulky conventional lens sets to be converted into single-layer structures with multi-functional integrated modulation characteristics.In addition,the dispersion of a metalens is more pronounced than that of a conventional refractive lens,but the zoom mode and axial zoom range of conventional diffracted metalenses are influenced by the inherent diffraction dispersion,and its resolution is constrained by the diffraction limit.To address this challenge,one method of designing super-resolution wavelength-controlled zoom metalenses has been proposed by simultaneously modulating the phase,dispersion,and amplitude.After enhancing the axial zoom capability of the metalens,we utilize a hierarchical particle swarm optimization(HPSO)algorithm to further compress the point spread function of the metalens,which makes the full width at half maximum(FWHM)of the metalens close to or even less than the diffraction limit(0.5λ/NA).Methods First,the relation between the focal length and angular frequency,i.e.,the dispersion constraint relationship,is set to n=2,and the theoretical group delay(G

关 键 词：光学设计 超透镜 波长调控光学变焦 振幅调控 分层粒子群优化算法 超分辨 

分 类 号：O436[机械工程—光学工程]