中文摘要：

为实现光纤扫描光源宽调谐范围内输出波长的高精度标定,提出了一种基于多波段混合气体吸收谱线的波长标定方法。采用分段阈值二阶导极值法和洛伦兹线型拟合法从混合气体吸收光谱中提取多条谱线中心位置,以其波长和驱动电压为参考点对Fabry-Perot（F-P）可调谐滤波器的迟滞非线性特性进行二次多项式拟合标定。将C2H2在C波段的吸收带与CO2在L波段的吸收带相结合,选取了21条C2H2谱线和16条CO2谱线作为波长参考。将本方法用于C＋L波段的光纤光栅（FBG）波长解调,在0~60℃范围内波长拟合标准差小于3.3pm,线性相关系数大于0.999 8,系统稳定性误差小于2.6pm。

英文摘要：

In order to recognize the output wavelength of fiber swept source precisely in a wide tuning range,a wavelength calibrating method based on mixed gas absorption lines in multiple near-infrared bands is proposed.Second derivative extremum with segmented threshold and Lorentzian line shape fitting are used to extract the accurate center positions of multiple absorption lines from mixed gas absorption spectrum.The absorption wavelengths and their corresponding drive voltages can be adopted as stable reference points to calibrate the nonlinear characteristics of the fiber Farby-Perot tunable filter.The nonlinearity is usually described using second order polynomial due to the small fitting error.In this paper,the absorption branch of acetylene in C-band and that of carbon dioxide in L-band are combined to provide wavelength reference.21absorption lines of acetylene and 16absorption lines of carbon dioxide are selected respectively according to the absorption intensity.When the proposed wavelength calibrating method is applied to get the wavelengths of FBG string in C＋L band,the standard deviation of wavelength linear fitting in the temperature range from 0℃to 60℃is no more than 3.3pm and the linear correlation coefficient is larger than 0.9998.The system has a good stability with a repeatability standard deviation less than 2.6pm.