为实现可调谐的多重Fano共振特性及设计高灵敏度折射率传感器,本文提出一种纳米环-七聚体金属-介电纳米天线结构,利用有限元方法(Finite Element Method,FEM)研究了Fano共振特性的影响因素和变化规律。研究表明,纳米环-七聚体金属-介电...为实现可调谐的多重Fano共振特性及设计高灵敏度折射率传感器,本文提出一种纳米环-七聚体金属-介电纳米天线结构,利用有限元方法(Finite Element Method,FEM)研究了Fano共振特性的影响因素和变化规律。研究表明,纳米环-七聚体金属-介电纳米天线的Fano共振特性对高度、入射角度和结构间隙的变化非常敏感;纳米天线的电场强度和电偶极源激发下的珀赛尔系数(Purcell factor,PF)可达134.74 V/m和3214,使得纳米天线中心位置附近的电场强度得到大幅增强;复合纳米天线结构具有较高的灵敏度S和品质因数FOM,分别为1400 nm/RIU和17 RIU^(-1),可作为评价高灵敏度折射率传感器的重要性能指标。本文为实现复合纳米天线结构中Fano共振的可调谐特性提供了一种可行途径,为表面增强拉曼散射、量子发射器和折射率传感器等实际应用奠定了坚实的理论基础。展开更多
Silkworm silk fiber is an attractive material owing to its remarkable mechanical characteristics,excellent optical properties,and good biocompatibility and biodegradability.However,nano-processing of the silk fiber is...Silkworm silk fiber is an attractive material owing to its remarkable mechanical characteristics,excellent optical properties,and good biocompatibility and biodegradability.However,nano-processing of the silk fiber is still a challenge limiting its applications in nanoengineering and related fields.Herein,we report localized near-field enhancement-assisted ablation with an ultrafast laser to break this bottleneck.Localized processing of silk fiber,including nano-holing,nano-grooving,and cutting could retain the key molecular structure building blocks and the pristine functionality of the silk fiber.An extremely narrow nanohole with a width of^64 nm was successfully achieved.The processed silk fiber can be used to transfer micro/nanoparticles and drugs,showing potential for biomedical engineering.The processing strategy developed in this study can also be extended to other materials,paving a new way for fabricating functional nanostructures with precisely controlled size and morphology.展开更多
本文基于时域有限差分方法(finite difference time domain,FDTD)研究了入射光波长、入射光偏振方向、纳米管几何形状、管壁厚度及内核和包埋介质的变化对椭圆截面金纳米管近场分布特征的影响.研究发现,入射光波长为纳米管等离激元共振...本文基于时域有限差分方法(finite difference time domain,FDTD)研究了入射光波长、入射光偏振方向、纳米管几何形状、管壁厚度及内核和包埋介质的变化对椭圆截面金纳米管近场分布特征的影响.研究发现,入射光波长为纳米管等离激元共振波长时,纳米管近场增强最大;入射光偏振方向与椭圆长轴夹角的增加会导致管内的场强迅速增大;椭圆管半短轴变大可以调节纳米管场强分布从两端高、中间低变化为均匀分布;内核和包埋介质介电常数的增大均会使得纳米管内部及周围场强逐渐减弱.展开更多
Strong near-field scattering enhancement (NFSE) of polyhedral oligomeric silsesquioxanes(POSS) nanoparticles (NPs) aggregates is found through physical simulation. An aggregation of N,N′-di-[3-(isobutyl polyhedral ol...Strong near-field scattering enhancement (NFSE) of polyhedral oligomeric silsesquioxanes(POSS) nanoparticles (NPs) aggregates is found through physical simulation. An aggregation of N,N′-di-[3-(isobutyl polyhedral oligomeric silsesquioxanes) propyl] perylene diimide(DPP) which possesses POSS as scatteres experimentally performs strong NFSE, which confirms the physical simulation results. Moreover, coherent random laser is triggered from the DPP aggregates in carbon disulfide. It is the NFSE of POSS NPs connected to both ends of DPP through covalent bonds and the NFSE of their aggregation thanks to DPP’s aggregation that is responsible for the coherent random laser. So, this work develops a method to improve weak scattering of system through construction of molecules, and opens a road to a variety of novel interdisciplinary investigations, involving molecular designing for disordered photonics.展开更多
基金the support from the National Key R&D Program of China(2017YFB1104300,2016YFA0200103 and 2018YFB1107200)the National Program for the Support of Top-notch Young Professionalsthe National Natural Science Foundation of China(51775303)。
文摘Silkworm silk fiber is an attractive material owing to its remarkable mechanical characteristics,excellent optical properties,and good biocompatibility and biodegradability.However,nano-processing of the silk fiber is still a challenge limiting its applications in nanoengineering and related fields.Herein,we report localized near-field enhancement-assisted ablation with an ultrafast laser to break this bottleneck.Localized processing of silk fiber,including nano-holing,nano-grooving,and cutting could retain the key molecular structure building blocks and the pristine functionality of the silk fiber.An extremely narrow nanohole with a width of^64 nm was successfully achieved.The processed silk fiber can be used to transfer micro/nanoparticles and drugs,showing potential for biomedical engineering.The processing strategy developed in this study can also be extended to other materials,paving a new way for fabricating functional nanostructures with precisely controlled size and morphology.
文摘本文基于时域有限差分方法(finite difference time domain,FDTD)研究了入射光波长、入射光偏振方向、纳米管几何形状、管壁厚度及内核和包埋介质的变化对椭圆截面金纳米管近场分布特征的影响.研究发现,入射光波长为纳米管等离激元共振波长时,纳米管近场增强最大;入射光偏振方向与椭圆长轴夹角的增加会导致管内的场强迅速增大;椭圆管半短轴变大可以调节纳米管场强分布从两端高、中间低变化为均匀分布;内核和包埋介质介电常数的增大均会使得纳米管内部及周围场强逐渐减弱.
基金supported by the National Natural Science Foundation of China(No.51673178,No.51273186,No.21574120,No.11874012,No.11404087,and No.11574070)Basic Research Fund for the Central Universities(No.WK2060200012)+3 种基金Science and Technological Fund of Anhui Province for Outstanding Youth(No.1608085J01)Fundamental Research Funds for the Central Universities of China,Postdoctoral Science Foundation(No.2015M571918 and No.2017T100442)the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sk lodowska-Curie Grant Agreement(No.744817)the Project of State Key Laboratory of Environment-friendly Energy Materials,Southwest University of Science and Technology(No.18zxhk10)
文摘Strong near-field scattering enhancement (NFSE) of polyhedral oligomeric silsesquioxanes(POSS) nanoparticles (NPs) aggregates is found through physical simulation. An aggregation of N,N′-di-[3-(isobutyl polyhedral oligomeric silsesquioxanes) propyl] perylene diimide(DPP) which possesses POSS as scatteres experimentally performs strong NFSE, which confirms the physical simulation results. Moreover, coherent random laser is triggered from the DPP aggregates in carbon disulfide. It is the NFSE of POSS NPs connected to both ends of DPP through covalent bonds and the NFSE of their aggregation thanks to DPP’s aggregation that is responsible for the coherent random laser. So, this work develops a method to improve weak scattering of system through construction of molecules, and opens a road to a variety of novel interdisciplinary investigations, involving molecular designing for disordered photonics.
