Mode characteristics of silver-coated inverted-wedge silica microdisks  

作　　者：BO Fang WANG XiaoOu LI Ying GAO Feng ZHANG GuoQuan XU JingJun 

机构地区：[1]The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, TEDA Applied Physics Institute and School of Physics,Nankai University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2015年第11期40-44,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Key Basic Research Program of China(Grant Nos.2011CB922003 and 2013CB328702);the National Natural Science Foundation of China(Grant Nos.11374165,11174153 and 10804054);the Program of Introducing Talents of Discipline to Universities(Grant No.B07013)

摘　　要：The characteristics of whispering gallery modes(WGM) in silver-coated inverted-wedge silica microdisks are theoretically investigated by using finite element method. Dielectric TE mode always exists in silver-coated inverted-wedge resonators; dielectric TM mode tends to couple with SPP modes; only pure interior surface plasmonic polariton(SPP) mode but not pure exterior SPP mode is observed in contrast to the metal-coated cylindrical and toroidal resonators. The dependence of quality factor of different kinds of WGMs on the radius of the resonator and the thickness of the coated silver layer are systematically analyzed. We find that the quality factors of the hybrid WGMs associated with SPP mode can reach 104. The maximum light intensity enhancement in ambient for a hybrid mode consisting of a dielectric TM mode and an exterior SPP mode can be obtained when a silver film of thickness ~40 nm is deposited. The silver-coated inverted-wedge silica resonators may be widely applied in sensing and surface enhanced Raman scattering.The characteristics of whispering gallery modes （WGM） in silver-coated inverted-wedge silica microdisks are theoretically in- vestigated by using finite element method. Dielectric TE mode always exists in silver-coated inverted-wedge resonators; die- lectric TM mode tends to couple with SPP modes; only pure interior surface plasmonic polariton （SPP） mode but not pure ex- terior SPP mode is observed in contrast to the metal-coated cylindrical and toroidal resonators. The dependence of quality fac- tor of different kinds of WGMs on the radius of the resonator and the thickness of the coated silver layer are systematically an- alyzed. We find that the quality factors of the hybrid WGMs associated with SPP mode can reach 104. The maximum light in- tensity enhancement in ambient for a hybrid mode consisting of a dielectric TM mode and an exterior SPP mode can be ob- tained when a silver film of thickness -40 nm is deposited. The silver-coated inverted-wedge silica resonators may be widely applied in sensing and surface enhanced Raman scattering.

关 键 词：MICROCAVITY whispering gallery mode surface plasmonic polariton 

分 类 号：TQ127.2[化学工程—无机化工]