一维镜像空气栅光子晶体折射率传感特性研究

Study on Refractive Index Sensing Property of One-Dimensional Mirror Air Gate Photonic Crystal

基于光子晶体的局域特性,提出一维镜像空气栅光子晶体结构。引入镜像结构在光子晶体中间形成缺陷腔,从而在透射谱禁带中得到谐振透射峰。基于传输矩阵法,建立谐振波长与光子晶体结构参数之间的关系模型。通过观测谐振透射峰值波长的漂移,利用矩形空气栅光子晶体结构即可实现待测气体样本参数的动态监测。以甲醛为待测样本,对该折射率传感器的Q值和灵敏度进行分析。结果表明,其Q值可达1739.48,其灵敏度可达816.67nm·RIU-1(RIU表示单位折射率),证明了结构设计的有效性。该结构可为空气污染监测和气体组分分析等方面提供一定的理论参考。

Based on the photonic local feature of photonic crystals, one-dimensional mirror air gate photonic crystal structure is proposed. Due to the introduction of mirror structure, a defect cavity is formed in the middle of the photonic crystal, and then the resonant transmission peak can be obtained in the forbidden band of transmission spectrum. The transfer matrix method is used to establish the relationship model between the resonant transmission peak and the structure parameters of the photonic crystals. Using the rectangular air gate photonic crystal structure, the dynamic monitoring of the detected gas sample parameters can be achieved from the shift of the resonant transmission peak. Taking formaldehyde as the detected sample, the Q value and sensitivity of the refractive index sensor are analyzed. The simulation results show that the Q value can attain to 1739.48 and the sensitivity can attain to 816.67 nm. RIU^-1 （RIU is refraction index unit）, which demonstrates the effectiveness of the sensing structure. The structure can provide certain theoretical reference for air pollution monitoring and gas component analysis.