摘要
为实现结构紧凑且具有较高品质因数的纳米级折射率传感器,文章提出了一种含金属挡板的金属-电介质-金属(MDM)波导与U型谐振腔侧边耦合的等离激元波导结构。利用有限元分析法,定量分析了结构参数和介质折射率对该结构透射谱线及折射率传感品质因数(FOM)的影响。研究结果表明,U型腔中的二阶谐振模式产生谱宽较窄的离散态透射谱,而带有金属挡板的MDM波导形成较宽的连续态透射谱,两者相干叠加激发具有反对称线型法诺(Fano)共振。经过结构参数扫描分析得到优化后的波导结构折射率传感灵敏度可达800 nm/RIU,FOM可达47382。该结构可以为纳米尺度的折射率传感器设计提供有效参考。
In order to achieve a compact structure to realize the refractive index sensor with high Figure of Merit(FOM)in a nanometer scale,a Metal-Dielectric-Metal(MDM)waveguide containing a metallic baffle side-coupled to U-shaped resonator is proposed to produce sharp and asymmetric Fano resonance.The asymmetric response line-shape of the Fano resonance is formed by the destructive interference between the wide continuous state generated by the single metallic baffle and the narrow discrete state excited by U-shaped resonator.The transmission properties of the proposed structure are numerically calculated by the finite element method,and the influence of structural parameters on the transmission spectrum and the value of FOM are analyzed quantitatively.The simulation results after parameter sweeping reveal that the FOM value of the optimized structure can attain to 47382 and the sensitivity of resonant wavelength with refractive index drift is 800 nm/RIU.The waveguide structure can provide effective references for the design of nano-scale refractive index sensor.
作者
唐丹丹
关建飞
TANG Dan-dan;GUAN Jian-fei(College of Electronic and Optical Engineering&College of Microelectronics,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)
出处
《光通信研究》
北大核心
2020年第3期49-54,共6页
Study on Optical Communications
基金
国家自然科学基金资助项目(61775102,61905177)
南京邮电大学科研基金资助项目(NY214058,NY220050)。
