Thickness bound for nonlocal wide-field-of-view metalenses  

作　　者：Shiyu Li Chia Wei Hsu 

机构地区：[1]Ming Hsieh Department of Electrical and Computer Engineering,University of Southern California,Los Angeles,CA 90089,USA

出　　处：《Light(Science & Applications)》2022年第12期3018-3027,共10页光（科学与应用)（英文版）

基　　金：supported by the National Science Foundation CAREER award(ECCS-2146021);the Sony Research Award Program.

摘　　要：Metalenses—flat lenses made with optical metasurfaces—promise to enable thinner,cheaper,and better imaging systems.Achieving a sufficient angular field of view(FOV)is crucial toward that goal and requires a tailored incidentangle-dependent response.Here,we show that there is an intrinsic trade-off between achieving a desired broad-angle response and reducing the thickness of the device.Like the memory effect in disordered media,this thickness bound originates from the Fourier transform duality between space and angle.One can write down the transmission matrix describing the desired angle-dependent response,convert it to the spatial basis where its degree of nonlocality can be quantified through a lateral spreading,and determine the minimal device thickness based on such a required lateral spreading.This approach is general.When applied to wide-FOV lenses,it predicts the minimal thickness as a function of the FOV,lens diameter,and numerical aperture.The bound is tight,as some inverse-designed multi-layer metasurfaces can approach the minimal thickness we found.This work offers guidance for the design of nonlocal metasurfaces,proposes a new framework for establishing bounds,and reveals the relation between angular diversity and spatial footprint in multi-channel systems.

关 键 词：DESIRED ANGULAR field 

分 类 号：O17[理学—数学]