title: A Plasmonic Temperature-Sensing Structure Based on Dual Laterally Side-Coupled Hexagonal Cavities.
abstract: A plasmonic temperature-sensing structure, based on a metal-insulator-metal (MIM) waveguide with dual side-coupled hexagonal cavities, is proposed and numerically investigated by using the finite-difference time-domain (FDTD) method in this paper. The numerical simulation results show that a resonance dip appears in the transmission spectrum. Moreover, the full width of half maximum (FWHM) of the resonance dip can be narrowed down, and the extinction ratio can reach a maximum value by tuning the coupling distance between the waveguide and two cavities. Based on a linear relationship between the resonance dip and environment temperature, the temperature-sensing characteristics are discussed. The temperature sensitivity is influenced by the side length and the coupling distance. Furthermore, for the first time, two concepts-optical spectrum interference (OSI) and misjudge rate (MR)-are introduced to study the temperature-sensing resolution based on spectral interrogation. This work has some significance in the design of nanoscale optical sensors with high temperature sensitivity and a high sensing resolution.
authors.affiliation: School of Electronic and Information Engineering, Southwest University, Chongqing 400715, China. yyxie@swu.edu.cn.
authors.forename: Yiyuan
authors.initials: Y
authors.lastname: Xie
authors.affiliation: School of Electronic and Information Engineering, Southwest University, Chongqing 400715, China. hyxiong@email.swu.edu.cn.
authors.forename: Yexiong
authors.initials: Y
authors.lastname: Huang
authors.affiliation: School of Electronic and Information Engineering, Southwest University, Chongqing 400715, China. xiaohua2013@swu.edu.cn.
authors.forename: Weihua
authors.initials: W
authors.lastname: Xu
authors.affiliation: School of Electronic and Information Engineering, Southwest University, Chongqing 400715, China. weilun@swu.edu.cn.
authors.forename: Weilun
authors.initials: W
authors.lastname: Zhao
authors.affiliation: School of Electronic and Information Engineering, Southwest University, Chongqing 400715, China. hc2014@swu.edu.cn.
authors.forename: Chao
authors.initials: C
authors.lastname: He
keywords: dual hexagonal cavities; finite-difference time-domain (FDTD) method; metal-insulator-metal (MIM) waveguide; plasmonic temperature sensor