Independently tunable dual resonant dip refractive index sensor based on metal–insulator–metal waveguide with Q-shaped resonant cavity  

作　　者：Haowen Chen Yunping Qi Jinghui Ding Yujiao Yuan Zhenting Tian Xiangxian Wang 陈颢文;祁云平;丁京徽;苑玉娇;田振廷;王向贤(College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,China;School of Science,Lanzhou University of Technology,Lanzhou 730050,China;Engineering Research Center of Gansu Province for Intelligent Information Technology and Application,Northwest Normal University,Lanzhou 730070,China)

机构地区：[1]College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,China [2]School of Science,Lanzhou University of Technology,Lanzhou 730050,China [3]Engineering Research Center of Gansu Province for Intelligent Information Technology and Application,Northwest Normal University,Lanzhou 730070,China

出　　处：《Chinese Physics B》2022年第3期316-322,共7页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 61865008);Northwest Normal University Young Teachers’ Scientific Research Capability Upgrading Program (Grant No. NWNU-LKQN202011)。

摘　　要：A plasmonic resonator system consisting of a metal–insulator–metal waveguide and a Q-shaped resonant cavity is proposed in this paper. The transmission properties of surface plasmon polaritons in this structure are investigated by using the finite difference in time domain(FDTD) method, and the simulation results contain two resonant dips. The physical mechanism is studied by the multimode interference coupled mode theory(MICMT), and the theoretical results are in highly consistent with the simulation results. Furthermore, the parameters of the Q-shaped cavity can be controlled to adjust the two dips, respectively. The refractive index sensor proposed in this paper, with a sensitivity of 1578 nm/RIU and figure of merit(FOM) of 175, performs better than most of the similar structures. Therefore, the results of the study are instructive for the design and application of high sensitivity nanoscale refractive index sensors.

关 键 词：surface plasmon polaritons refractive index sensors metal–insulator–metal(MIM)waveguide multi-mode interference coupling theory 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]