为了降低外界环境温度变化对单缺陷光子晶体折射率传感的干扰,提出了一种双缺陷空气栅光子晶体的传感模型。通过紧束缚法分析光子晶体双缺陷模的产生机理,并结合传输矩阵理论分析该光子晶体结构的光学传输特性。针对折射率和温度的交叉敏感问题,提出了一种消除温度干扰的方法,并建立两缺陷模波长与光子晶体结构参数之间的关系模型。利用该空气栅光子晶体,通过观测双缺陷峰波长的漂移,即可实现待测气体样本参数的动态监测。通过数值模拟可以发现,两缺陷模的波长均与待测气体的折射率呈线性关系,该传感具有结构简单和精度高等优点。
In order to reduce the interference of ambient temperature changes to the single defect photonic crystal sensing, a double defect mode sensing model of air gate photonic crystal is proposed. The mechanism of the double defect mode is analyzed by tight-binding method, and the optical transmission property of the photonic crystal structure is analyzed by the transmission matrix method. For the cross-sensitive issue of temperature and refractive index, a method to eliminate the temperature interference is proposed, and the relation model between the two defect mode wavelengths and the structure parameters of the photonic crystal are established. Using the 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. The numerical simulation shows that the relation between double defect sensor has the features of double defect mode wavelengths and the gas refractive index is linear. The sensor has the advantages of simple structure and high precision.