摘要
提出了一种亚波长金属光栅/电介质/金属混合波导传感结构,在结构中可产生导模共振模式、表面等离子激元共振模式和局域表面等离子体模式,模式之间互相耦合,从而在反射光谱中形成两个窄带共振缺陷峰。通过研究共振缺陷峰处磁场分布和结构参数对反射谱的影响,分析了结构中的共振模式。根据导模共振原理和表面等离子体共振形成条件,建立共振缺陷峰波长与结构参数之间的关系模型,通过观察共振缺陷峰波长的漂移实现待测样本气体浓度的动态实时监测。以多孔硅为传感载体、甲醛气体为待测样本,分析传感器的品质因数和灵敏度。结果表明,两个窄带共振缺陷峰的品质因数分别可达42.3RIU-1和78.5RIU-1,灵敏度分别为466nm/RIU和628nm/RIU。
A subwavelength metal grating/dielectric/metal hybrid waveguide sensing structure is proposed. In the structure, the resonance mode of guided mode, surface plasmon polariton resonance mode and local surface plasmon polariton mode can be generated, and these modes are coupled with each other, resulting in two narrow band resonance defect peaks in the reflection spectrum. After studying the magnetic field distribution at the resonance defect peaks and the influence of structural parameters on the reflection spectrum, we analyze the resonance modes in the structure. According to the principle of mode resonance of guided mode and surface plasmon resonance, the relationships between the wavelength of resonance defect peaks and the structural parameters are established. The drifts of resonance peaks wavelengths are observed, and the dynamic real-time monitoring of the gas samples can be realized. The porous silicon is used as the sensing carrier, and the formaldehyde is used as the sample to be tested. The quality factor and sensitivity of the sensor are analyzed. The results shows that the quality factors of two narrow band resonance defect peaks are 42.3 RIU-1 and 78.5 RIU-1, and the sensitivities are 466 nm/RIU and 628 nm/RIU, respectively.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2018年第1期253-259,共7页
Chinese Journal of Lasers
基金
国家自然科学基金(61201112
61475133)
河北省自然科学基金(F2016203188
F2016203245)
河北省普通高等学校青年拔尖人才计划(BJ2014056)
燕山大学青年教师自主研究计划(14LG013)
关键词
传感器
金属光栅
导模共振
表面等离子激元
sensors
metal grating
guided mode resonance
surface plasmon polariton
