摘要
引入了色散介质的时域有限差分法散射场方程,并针对光子扫描隧道显微镜的带金属尖光纤扫描成像问题进行三维的数值模拟。在考虑了光纤和样品相互作用的情况下,采用等效入射波法设置入射波,探针扫描模式为等高扫描模式,从成像分辨力和灵敏度的角度,比较了不同入射角、不同的光纤样品间距,不同金属类型,及不同金属尖大小的成像情况。数值模拟结果显示,带金属颗粒光纤探针尖的光子扫描隧道显微镜在成像分辨力和灵敏度上有显著的改进,而带不同类型金属颗粒情况下对分辨力影响不大,灵敏度是银最好。
The image of photon scanning tunnel microscope (PSTM), which uses fiber probe with metallic nanoparticle tip, is analyzed with the finite-difference time-domain (FDTD) formulation of dispersive materials. With considering the interaction between the field of the fiber probe and the sample, the influences of different angle of incidence, different distance between probe and sample, different kinds of metal and different size of the metallic nanoparticle on the resolution and the sensitivity of PSTM are investigated with the equivalent incident wave method. The simulated results show that the image of PSTM with metallic nanoparticle tip has higher resolution and sensitivity. The influences of different kinds of metallic nanoparticle on the resolution are not obvious, while the image of PSTM which uses fiber probe with silvery nanoparticle tip has the best sensitivity.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2005年第4期470-474,共5页
Acta Optica Sinica
基金
国家自然科学基金(30270367)
教育部博士点基金(20020141018)资助课题。
关键词
近场光学
时域有限差分法
光子扫描隧道显微镜
色散介质
near-field optics
finite-difference time-domain
photon scanning tunnel microscope
dispersive materials
