摘要
提出了一种X-两环的金属周期性阵列结构,该结构由两个同心圆环包围中心X型构成.利用时域有限差分算法研究了该结构的光学特性.计算表明,当光入射到金属表面时,能够在结构中产生法诺共振现象,并在不同的位置下产生共振谷.同时,共振谷的出现又明显依赖于结构的相对参数(X的臂长、内外环的距离、内外环宽度、周期、环数、X所呈的角度),从而可以通过调节结构的相对参数来实现对结构的共振强度及共振谷位置的调控.另外,进一步分析了在不同环境折射率条件下该结构共振谷的变化规律,可以得出该结构也对周围的环境折射率有着较高的敏感度,最高可达1300 nm/RIU.结果表明,该结构在环境折射率传感器及某些光子器件的应用方面有着潜在的价值.
In this paper, the metal periodic array structure of X-two ring based on the principle of Fano resonance is proposed,which is composed of two concentric rings around the center X. The optical properties of the structure are investigated by using the finite difference time domain method. According to the simulated transmission spectra, electric field distribution and charge distribution, when linearly polarized light is incident to the metal surface, Fano resonance can be excited and the interaction between resonance modes can be produced in the structure of X-two ring, which can make resonance valleys generated at different positions. Fano resonance is mainly formed by the coherent interference between a bright mode with the larger radiation broadening and a dark mode with the weak radiation broadening, thus the structural resonance valley of X-two ring based on Fano resonance is strongly dependent on the relative parameters of the structure（the arm length of X, the distance between the inner ring and outer ring, the width of the inner ring and outer ring, the period, the number of ring, and the angle of X）. In other words, over the wavelength range of 450 nm to 3000 nm, the intensity and position of the structural resonance valley are adjustable as the change of the relative geometric parameters of the structure. In addition, due to weak radiation damping and strong local electromagnetic field enhancement of Fano resonance, the resonance frequency and line type can significantly shift with the change of the environmental refractive index. Therefore, the further analysis of the variation of the structural resonance valley under the conditions of different refractive indices can be concluded that the structure of X-two ring has a higher sensitivity to the refractive index of surrounding environment, up to 1300 nm/RIU. The above results show that the structure of X-two ring not only is simple, economical, compact and efficient, but also has great potential applications in refractive index sensors and some photo
作者
潘庭婷
曹文
邓彩松
王鸣
夏巍
郝辉
Pan Ting-Ting;Cao Wen;Deng Cai-Song;Wang Ming;Xia Wei;Hao Hui(Key Laboratory on Opto-Electronic Technology of Jiangsu Province,School of Physics Science and Technology,Nanjing Normal University,Nanjing 210023,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第15期321-327,共7页
Acta Physica Sinica
基金
国家自然科学基金(批准号：51775283,51405240)
江苏省自然科学基金(批准号：BK20161559)
江苏省高校自然科学研究项目(批准号：16KJB510018)
江苏省高校研究生培养创新工程(批准号：KYLX16_1289)资助的课题
关键词
法诺共振
时域有限差分算法
周期性结构
Fano resonance
finite-difference time-domain method
periodic structure
