非均匀镀膜微球产生的光子纳米喷流特性研究  

Characteristics of photonic nanojets generated by patchy microspheres

作　　者：贾睿 杨智焜 潘晓燕 彭起 JIA Rui;YANG Zhikun;PAN Xiaoyan;PENG Qi(National Key Laboratory of Optical Field Manipulation Science and Technology,Chinese Academy of Sciences,Chengdu 610209,China;Key Laboratory of Optical Engineering,Chinese Academy of Sciences,Chengdu 610209,China;Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院光场调控科学技术全国重点实验室,成都610209 [2]中国科学院光束控制重点实验室,成都610209 [3]中国科学院光电技术研究所,成都610209 [4]中国科学院大学,北京100049

出　　处：《物理学报》2025年第9期148-158,共11页Acta Physica Sinica

基　　金：中国科学院重点实验室基金(批准号:CXJJ-22S008)资助的课题.

摘　　要：光子纳米喷流,近年来逐渐引起科研人员的关注.它具有独特的性质,例如高强度、高局域性和亚波长尺度的聚焦能力,是一种具有波长量级强聚焦的光束.由于光子纳米喷流聚焦处的半高全宽通常可以超越衍射极限,且可以保持较长距离的高强度喷流,因而光子纳米喷流能够显著提高成像分辨率.本研究通过数值模拟的方法探讨了非均匀镀膜微球在不同覆盖面积、照射角度及不同浸没介质折射率下,光子纳米喷流的特性.结果表明,非均匀镀膜微球能产生具有“S”型与“Y”型光子钩特性和超衍射极限的光子纳米喷流,并在特定条件下触发谐振现象.这一研究为非均匀镀膜微球在超分辨成像等领域的应用提供了理论支持.Photonic nanojet(PNJ)has gradually attracted the attention of researchers in the recent years.PNJ has unique properties,such as high intensity,high localization and subwavelength scale focusing ability,making it a narrow beam with wavelength scale.The full-width at half maximum(FWHM)of PNJ at the focus can exceed the diffraction limit while maintaining high intensity with a long distance,which can significantly enhance the imaging resolution.In this work,the characteristics of PNJ are explored through numerical simulation,with a focus on studying the patchy microspheres under various conditions,including coverage area,incident angle,and the refractive index of the immersion medium.The findings reveal that when the microsphere size is fixed and the coverage area accounts for 69%,the performance of PNJ is optimal.Under this condition,adjusting the incident angle to-5.74°can accurately position the PNJ focal point on the microsphere surface.Furthermore,at this specific angle,the patchy microspheres can generated PNJ with“S”-typed and“Y”-typed field intensity distribution,and the FWHM is reduced to 180 nm,significantly exceeding the traditional diffraction limit.This optimization strategy not only facilitates super-resolution focusing,but also greatly enhances both the intensity and efficiency of the PNJ.Additionally,this study demonstrates that the PNJ performance improves when the refractive index ratio between the patchy microsphere and the immersion medium approaches 1.4.Notably,a resonance effect occurs when the refractive index ratio reaches 1.48,resulting in enhanced PNJ performance.In this case,the PNJ focal point remains on the surface of the microsphere,with an FWHM of 180 nm,while the light intensity is further amplified to approximately three times the intensity of the PNJ generated by the microspheres without resonance effect.This research provides theoretical support for the application of patchy microspheres in fields such as super-resolution imaging.

关 键 词：光子纳米喷流 亚波长聚焦 超分辨成像 Mie氏散射 

分 类 号：O436[机械工程—光学工程]