Sub-50 nm optical imaging in ambient air with 10× objective lens enabled by hyper-hemi-microsphere  

作　　者：Guangxing Wu Yan Zhou Minghui Hong 

机构地区：[1]Department of Electrical and Computer Engineering,National University of Singapore,4 Engineering Drive 3,Singapore,117576,Singapore [2]School of Aerospace Engineering,Xiamen University,Xiamen,361005,China [3]Present address:Peng Cheng Laboratory,Shenzhen,518055,China

出　　处：《Light(Science & Applications)》2023年第3期398-408,共11页光（科学与应用)（英文版）

基　　金：Ministry of Education,Singapore,under Academic Research Fund Tier 2(Award MOE2019-T2-2-147).

摘　　要：Optical microsphere nanoscope has great potential in the inspection of integrated circuit chips for semiconductor industry and morphological characterization in biology due to its superior resolving power and label-free characteristics.However,its resolution in ambient air is restricted by the magnification and numerical aperture(NA)of microsphere.High magnification objective lens is required to be coupled with microsphere for nano-imaging beyond the diffraction limit.To overcome these challenges,in this work,high refractive index hyper-hemi-microspheres with tunable magnification up to 10×are proposed and realized by accurately tailoring their thickness with focused ion beam(FIB)milling.The effective refractive index is put forward to guide the design of hyper-hemi-microspheres.Experiments demonstrate that the imaging resolution and contrast of a hyper-hemi-microsphere with a higher magnification and larger NA excel those of a microsphere in air.Besides,the hyper-hemi-microsphere could resolve~50 nm feature with higher image fidelity and contrast compared with liquid immersed high refractive index microspheres.With a hyper-hemi-microsphere composed microscale compound lens configuration,sub-50 nm optical imaging in ambient air is realized by only coupling with a 10×objective lens(NA=0.3),which enhances a conventional microscope imaging power about an order of magnitude.

关 键 词：AMBIENT immersed refractive 

分 类 号：O43[机械工程—光学工程]