Author Affiliations
Abstract
1 School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
2 Zhangjiang Laboratory, Shanghai 201204, China
3 Shanghai Key Laboratory of Modern Optical System, University of Shanghai for Science and Technology, Shanghai 200093, China
The chiral feature of an optical field can be evaluated by the parameter of -factor enhancement, which is helpful to enhance chiroptic signals from a chiral dipole. In this work, the superchiral spot has been theoretically proposed in metal-insulator-metal waveguides. The -factor enhancement of the superchiral spot can be enhanced by 67-fold more than that of circularly polarized light, and the spot is confined in the deep wavelength scale along each spatial dimension. Moreover, the position of the superchiral spot can be tuned by manipulating the incident field. The tunable superchiral spot may find applications in chiral imaging and sensing.
circular dichroism superchiral spot radially polarized beam metal-insulator-metal waveguide Chinese Optics Letters
2023, 21(1): 013601
研究同侧、异侧和反对称双loop-stub(LS)谐振腔侧边耦合波导结构中的多重类电磁诱导透明效应,并利用有限元方法分别对这三种结构的光学透射特性进行数值模拟。结果表明,这三种结构的透射谱、磁场分布和色散强烈地依赖结构参数。着重讨论双LS谐振腔相邻两个stub腔的距离或两个水平分支的距离对透射特性的影响。随着距离的减小,两个LS腔之间的耦合增强,出现多个透射峰和透射谷(即阻带),多重类电磁诱导透明效应显著。此外,讨论了同侧双LS腔波导结构相邻两个stub腔的距离为零时,竖直分支宽度、水平分支宽度、总水平分支长度等参数对透射谱的影响。侧边耦合金属纳米波导结构在未来的集成光学有潜在的应用价值,如滤波器、传感器和慢光装置等。
光学器件 表面等离激元 电磁诱导透明 金属-介质-金属波导 有限元法 光学学报
2022, 42(10): 1023002
1 桂林电子科技大学 广西无线宽带通信与信号处理重点实验室, 广西 桂林 541004
2 深圳大学 光电子器件与系统教育部重点实验室, 广东 深圳 518060
针对现阶段表面等离子体激元(SPP)传感器存在灵敏度低、结构制造复杂等问题，提出了一种由金属-绝缘体-金属波导和嵌入银纳米棒的谐振腔构成的高灵敏度、可调谐的SPP传感器。采用时域有限差分法对所设计传感器的光传输特性及传感特性进行了理论研究。仿真结果表明：当谐振腔引入或者不引入银纳米棒时，传输谱在500~3500 nm波长范围会呈现4个或者2个谐振峰；该结构的折射率灵敏度高达2116.72 nm/RIU,品质因数为27.503；通过对谐振腔填充乙醇，该结构可实现对环境温度的测量，温度灵敏度可达0.982 nm/℃。
等离子体激元 金属-绝缘体-金属波导 谐振腔 传感器 灵敏度 plasmon polariton metal-insulator-metal waveguide resonant cavity sensor sensitivity
Author Affiliations
Abstract
1 Department of Technical Cybernetic, Samara National Research University, Samara 443086, Russia
2 Institute of RAS-Branch of the FSRC “Crystallography and Photonics”, RAS, 151 Molodogvardeiskaya, Samara 443001, Russia
We propose a highly refractive index sensor based on plasmonic Bow Tie configuration. The sensitivity of the resonator design is enhanced by incorporating a nanowall (NW) in a modified Bow Tie design where sharp tips of V-junction are flattened. This approach provides high confinement of electric field distribution of surface plasmon polariton (SPP) mode in the narrow region of the cavity. Consequently, the effective refractive index (neff) of the mode increases and is highly responsive to the ambient medium. The sensitivity analysis of the SPP mode is calculated for six resonator schemes. The results suggest that the NW embedded cavity offers the highest mode sensitivity due to the large shift of effective index when exposed to a slight change in the medium refractive index. Moreover, the device sensitivity of the proposed design is approximated at 2300 nm/RIU which is much higher than the sensitivity of the standard Bow Tie configuration.
Bow Tie configuration plasmonic sensor metal-insulator-metal waveguide refractive index sensor Photonic Sensors
2020, 10(3): 223
Author Affiliations
Abstract
1 School of Architecture & Urban Planning, Lanzhou Jiaotong University, Lanzhou 730070, China
2 School of Science, Lanzhou University of Technology, Lanzhou 730050, China
In this paper, we describe a new method to improve fast-light transmission, which uses cascades. We design a simple plasmonic device that enables plasmonic-induced absorption (PIA). It consists mainly of two parallel rectangular cavities. The numerical results simulated by using the finite element method (FEM) confirm its function. The corresponding group delay-time can reach –0.146 ps for the PIA window. Based on this result, we propose a cascade device, with the dual-rectangular cavity system as building block, to improve fast-light transmission even more. The results indicate that the cascade scheme can increase the group delay-time to –0.456 ps, which means the fast-light feature is substantially enhanced compared with the non-cascading approach. The effect of the distance between two cascade resonators and other structural parameters is also investigated. Finally, we use this design concept to build a refractive-index sensor with a sensitivity of 701 nm/RIU.
Plasmonic-induced absorption fast light metal-insulator-metal waveguide finite element method Photonic Sensors
2020, 10(2): 162
通过在金属-绝缘体-金属表面等离激元波导单侧引入平行的双谐振腔结构，实现了等离激元诱导透明效应的数值模拟，基于谐振耦合导致的模式分裂理论揭示了单等离激元诱导透明透射峰的形成机理，并数值研究了透射峰幅度及谱宽与模型结构参数的依赖关系。在此基础上设计了在波导双侧三腔结构，并对其透射谱进行了数值仿真，结果表明：选取适宜腔长及间距参数，可以在三腔模型中产生双等离激元诱导透明透射峰，并且峰值位置可以随腔长以近似线性关系改变。
表面等离激元 金属-绝缘体-金属波导 有限元法 等离激元诱导透明 surface plasmons polaritons metal-insulator-metal waveguide finite element method plasmonic-induced transparency
1 桂林电子科技大学信息与通信学院, 广西 桂林 541004
2 桂林电子科技大学计算机科学与工程学院, 广西 桂林 541004
3 广西信息科学实验中心, 广西 桂林 541004
采用有限时域差分法，研究了内嵌金属块长度与夹缝宽度对金属绝缘体金属波导结构的光透射特性的影响。研究发现，此结构相比较于单一直波导而言，出现了一个很明显的透射峰。并且当金属块的长度较大时，其与波导上表面的金属之间形成的夹缝会构成法布里珀罗腔，高阶共振模式被激发，能量在腔内不断谐振，从而产生多个不断衰减的共振峰。同时，提出了一种基于内嵌双金属块结构的表面等离激元带通滤波器，此滤波器在共振峰以外波段的透射率可以下降为0，且其共振波长可以通过改变金属块的长度等参数进行调节。
表面光学 表面等离激元 滤波器 有限时域差分法 金属绝缘体金属波导 激光与光电子学进展
2016, 53(9): 092401
在可见光到近红外频段，利用时域有限差分数值模拟计算方法，研究了一种多圆环形金属-介质-金属等离子体波导结构的电磁传输特性.结果表明，由于谐振作用，不同波长电磁波能量被分别束缚于圆环中，之后被耦合到各出口端进行传输，从而实现了电磁波的多路分频传输功能.圆环的共振波长与圆环半径之间存在近似线性关系，且随着圆环内填充介质折射率的增大呈现明显的红移现象；各出口端共振波长对应电磁能量的传输率随着介质波导与圆环间耦合厚度的增大而急剧降低.利用电磁波共振理论阐述了电磁能量的谐振束缚现象，与数值模拟结果吻合.研究结果可应用于未来光子集成器件中.
金属-介质-金属波导 多路分频 传输 时域有限差分方法 光学器件 Metal-insulator-metal waveguide Demultiplexing Transmission Finite-difference time-domainmethod Optical devices
设计了一种亚波长圆环形三通道金属-介质-金属(MIM)波导分解复用器。利用时域有限差分(FDTD)法，在可见光到近红外频段研究了该结构的电磁传输特性，发现满足谐振条件的电磁波可以在圆环中发生多级谐振现象。通过优化出口通道在圆环上的位置，成功实现了圆环二、三、四级谐振模式的分离功能。此外，圆环的谐振波长可以通过设置圆环的半径进行调制。该微结构对光波具有束缚与传输功能，解决了光信号谐振模式分离传输问题，在光集成与通讯等方面有较好的应用前景。
光学器件 亚波长结构 金属-介质-金属波导 分解复用器 谐振模 时域有限差分法 激光与光电子学进展
2016, 53(4): 042301
