研究了双环级联谐振腔传感器透射谱线包络的拟合方法, 用不同拟合函数拟合双环透射谱包络, 并利用单环和游标效应分析其拟合误差.理论计算表明, 将探测极限提高10倍时, 对包络作高斯拟合得到的传感器探测误差仅为0.41%.实验结果表明用波长探测方式, 未拟合时传感器探测误差高达14.96%, 而通过对包络作高斯拟合得到的传感器探测误差只有0.45%.仿真和实验结果均验证了高斯函数的拟合效果最好, 可在游标效应增大灵敏度的基础上, 进一步提高传感器的探测极限和探测精度.

The methods of fitting the envelope of the transmission in a cascaded double-ring resonator sensor were studied. Different fitting functions was used to fit the double-ring transmission spectrum envelope and the fitting error by the single ring and vernier effect was analyzed. The theoretic calculation shows that the detection error of the sensor obtained by Gaussian fitting of the envelope is only 0.41% when the detection limit is increased by 10 times. The experimental results show that for the wavelength detection method, the detection error is as high as 14.96% without fitted. However, the sensor detection error is only 0.45% with Gaussian fitting function. The simulation and experimental results prove that the Gaussian function is the best fitting method, which can further improve the detection limit and the detection accuracy of the sensor based on vernier effect.