The Filter Characteristic Research of Metal-Insulator-Metal Waveguide with Double Overlapping Annular Rings

Abstract

A metal-insulator-metal (MIM) waveguide with double overlapping annular rings is proposed, and its transmission properties are simulated and characterized by the finite element method. The results show that the transmission valley appears in the transmission spectra when the straight MIM waveguide output port has a positional angular deviation θ relative to the incident port. Compared with the symmetric structure (θ=0°), the filtering properties of the asymmetric structures (θ>0°) are greatly improved. And compared to the MIM waveguide with single ring resonator, the filter characteristic of MIM waveguide with the double overlapping rings is superior to that of single ring resonator. For the asymmetric structure, due to the fact that parts of coupled MIM waveguide output port locates at the magnetic nodes of the standing waves in the ring resonator, there is a transmission minimum. Moreover, the asymmetric MIM waveguide can easily detect the refractive index changes of the filled media inside of resonator cavities, its potential applications in sensors.

Breaking the Symmetry of a Metal–Insulator–Metal-Based Resonator for Sensing Applications

“…Compared with the symmetric structure (θ = 0°), the sensing performance of the asymmetric case 3 structure is greatly improved when θ increases from 0° to 30°. For the asymmetric structure (θ > 0°) because parts of EM wave locate at the magnetic nodes of the standing waves in the resonator, there is a transmittance dip [71]. As seen in Fig.…”

Research on the Resonance Modes Separation of the Subwavelength Ring-Shaped Demultiplexer

“…微 腔 多 路 分 频 功 能 [16] ； 圆 盘 型 三 通 道 波 长 分 离 功 能 [17] ； 矩 形 微 腔 独 立 F-P 谐 振 模 [18] ， 单 边 耦 合 矩 形 多 重 F-P 谐振 [19] 等。 前期对各类 MIM 波导结构的研究， 主要利用微腔的共振作用实现电磁波的滤波 [6][7][8][9][10][11][12][13][14][15] 、 分频等功能 [16][17][18][19] ， 而对 微腔的谐振模及调控方面的报道非常少见。最近， 纳米圆盘型 MIM 波导中谐振频率的抑制、 劈裂现象被报 道 [20] ； 随后， 基于 MIM 波导的多矩形谐振腔的滤波器被提出 [21] 。基于亚波长 MIM 波导的多级谐振模的分离对 光子器件具有重要意义。本文利用时域有限差分(FDTD)数值模拟方法， 在可见光到近红外频段研究了亚波 [22] 。 空 气 端 口 port 1 与 端 口 port 2、 port 3 之 间 夹 角 分 别 为 90°和 120°， 端 口 与 圆 环 的 宽 度 固 定 为 w= 50 nm， 圆环与各端口耦合间隙固定 g=10 nm， 圆环半径 r 为内、 外半径 r1、 r2 的平均值。由于波导的宽度设定 为 50 nm， 所以波导中支持 TM 模式波 [20] ， 其色散关系为 [23] ：…”

Band-pass and Band-stop Plasmonic Filters Based on Wilkinson Power Divider Structure

“…Another lter based on rings was proposed. Double overlapping annular rings were used in this structure [19]. in another paper, two plasmonic lters were designed that in these structures were used of the circular ring resonator.…”