非对称银膜多孔硅-氟化钙等离子体波导及其波导灵敏度特性  

Porous silicon-calcium fluoride plasma waveguide with asymmetric Ag film and its sensitivity characteristics

作　　者：王芳 陈亚珂[1] 李传强 马涛 卢颖慧 刘恒[1,4] 金婵 Wang Fang;Chen Ya-Ke;Li Chuan-Qiang;Ma Tao;Lu Ying-Hui;Liu Heng;Jin Chan(College of Electronic and Electrical Engineering,Henan Normal University,Xinxiang 453007,China;Key Laboratory of Interfacial Physics Technology Project,Chinese Academy of Sciences,Shanghai 201800,China;Key Laboratory Optoelectronic Sensing Integrated Application of Henan Province,Henan Normal University,Xinxiang 453007,China;Academician Workstation of Electromagnetic Wave Engineering of Henan Province,Henan Normal University,Xinxiang 453007,China)

机构地区：[1]河南师范大学电子与电气工程学院,新乡453007 [2]中国科学院界面物理技术重点实验室,上海201800 [3]河南师范大学,河南省光电传感集成应用重点实验室,新乡453007 [4]河南师范大学,河南省电磁波工程院士工作站,新乡453007

出　　处：《物理学报》2021年第22期55-65,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62075057);中国科学院界面物理技术重点实验室(批准号:CASKL-IPT2003);河南省高等学校重点科研项目基础研究项目(批准号:19B510006);河南师范大学博士启动课题(批准号:gd17167,5101239170010)资助的课题.

摘　　要：本文研究了一种非对称银膜多孔硅-氟化钙混合等离子体波导,并对其模式特性和波导灵敏度进行了分析.利用有限元方法分析了波导中两个不同偏振态基模(PM 1和PM 2)的有效折射率、传输损耗、归一化有效模场面积、品质因数和波导灵敏度,并对几何参数进行优化.结果表明,在中红外波长3.5μm附近,非对称银膜多孔硅-氟化钙混合等离子体波导具有良好的模场约束能力和低损耗特性;此时,PM 1和PM 2的归一化有效模场面积分别为0.30和0.52,传输损耗分别为0.019 dB/μm和0.016 dB/μm,品质因数分别为1335.54和1594.99,波导灵敏度分别为0.080和0.064.通过制造容差分析可知,非对称银膜多孔硅-氟化钙混合等离子波导在±10 nm的制造容差范围内保持了良好的模式特性和传感特性.非对称银膜多孔硅-氟化钙混合等离子体波导结构简单,损耗小,易于实现表面等离子体传感,为无标记生物化学传感提供了一种可行的方案,另外,波导的非对称结构也可用于模式偏振态变换.In this paper,a porous silicon-calcium fluoride hybrid plasmonic waveguide(PS-CaF_(2) HPW)with an asymmetric silver film is studied.The PS-CaF_(2) HPW is composed of a PS strip waveguide deposited with asymmetric CaF_(2) and Ag thin film layers on an SiO_(2) substrate.In the mid-infrared(MIR)region,the mode characteristics and waveguide sensitivity of the mode in the PS-CaF_(2) HPW are simulated by using the finite element method(FEM).The results show that there are two fundamental modes(PM_(1) and PM_(2))with different polarization states in the PS-CaF_(2) HPW.The real part of the effective refractive index(Re(n_(eff))),transmission loss(α),normalized effective mode field area(A),quality factor(FOM)and sensitivity(S_(wg))for each of the PM_(1) and the PM_(2) are studied and optimized.Moreover,the effect of temperature on the performances of the PS-CaF_(2) HPW is also analyzed.Firstly,the mode field distributions calculated by the FEM indicate that the mode field energy for each of the PM_(1) and PM_(2) in the PS-CaF_(2) HPW is mostly restricted to the PS layer and CaF_(2) layer.Comparing with conventional dielectric waveguides,the mode field energy of the PS-CaF_(2) HPW is well confined in the PS layer and CaF_(2) layer.The geometric parameters of the PS-CaF_(2) HPW are optimized by changing the geometric parameters(W_(1),W_(2),and W_(3)).When W_(1)=1500 nm,W_(2)=300 nm,W_(3)=70 nm,and the operating wavelength is~3.5μm,α and FOM are 0.019 dB/μm and 1594.99 for the PM_(1),and α and FOM are 0.016 dB/μm and 1335.54 for the PM_(2),respectively.Secondly,the waveguide sensitivity of the PS-CaF_(2) HPW is analyzed.The results show that the size of PS layer has a great influence on the waveguide sensitivity.The waveguide sensitivity decreases with the size of the PS layer increasing.In addition,the PS-CaF_(2) HPW has good temperature resistance.Moreover,temperature has almost no effect on Re(n_(eff)),nor α nor A nor FOM nor S_(wg) in a temperature range from-40 K to 40 K.Finally,the fabrication tolerances of the

关 键 词：混合等离子波导 表面等离子体 传输特性 波导灵敏度 

分 类 号：TB383.2[一般工业技术—材料科学与工程] O53[理学—等离子体物理]