基于KMeans的MG-Y激光器准连续调谐方法

Quasi-continuous Tuning Method of MG-Y Laser based on KMeans

【目的】光纤光栅传感系统的光源为系统提供能量,稳定且连续的光源对于整个解调系统的应用至关重要。当将调制光栅Y分支(MG-Y)激光器作为光纤光栅解调系统的光源时,需解决MG-Y激光器难以在所需特定波长范围内快速获得稳定且连续的波长调谐问题。【方法】为实现MG-Y激光器快速获得稳定且连续的波长,文章提出了K均值(KMeans)聚类模型,并将其运用到MG-Y激光器快速获取高质量电流-波长查找表(LUT)的构建方法中。【结果】通过KMeans聚类模型方法结合MG-Y激光器调谐特性,可以快速获得构建LUT中相位调谐区域内最优调谐参数曲线的质心点,消耗时间约18.26 s,再依据MG-Y激光器自身的左、右和相位的调谐特性,采用均匀插值的方法来实现MG-Y激光器的波长精细调谐。使用KMeans聚类模型得到全调谐范围LUT,按照一定间隔筛选得到目标LUT。激光器按照该目标LUT下发命令的输出波长,实测波长的均值与目标波长的误差绝对值的均值为0.18 pm,误差绝对值的标准差为0.52 pm。从而可将MG-Y激光器作为光纤光栅传感系统的稳定光源来使用。【结论】经实验验证,传统的人工完成寻找每个相位调谐区域找到质心点的用时至少需要。30 min。通过KMeans聚类模型方法,完成同样操作,能大幅缩短寻找质心点的时间。并且通过该方法可控制MG-Y激光器实现输出准连续调谐的稳定波长。

【Objective】The light source of fiber grating sensing system provides energy for the system.The stable and continuous light source is crucial for the application of the whole demodulation system.When the Modulated Grating Y-branch(MG-Y)laser is used as the light source of the fiber grating demodulation system,it is necessary to solve the problem that it is difficult for the MG-Y laser to quickly obtain the stable and continuous tuning within the required specific wavelength range.【Methods】In order to obtain the stable and continuous wavelengths quickly for MG-Y lasers,the K-Means(KMeans)clustering model is proposed and applied to obtain high-quality current-wavelength Look Up Table(LUT)for MG-Y lasers.【Results】By combining the tuning characteristics of the MG-Y laser with the KMeans clustering model method,the centroid of the optimal tuning parameter curve in the phase tuning region of the LUT can be quickly obtained with time of about 18.26 s.Then,according to the tuning characteristics of the left,right and phase of the MG-Y laser itself,the fine tuning of the MG-Y laser wavelength can be achieved by uniform interpolation method.The LUT with the full tuning range is obtained from the KMeans clustering model,and the target LUT is selected at a certain interval.According to the output wavelength issued by the laser according to the target LUT,the mean value of the measured wavelength and the absolute value of the error of the target wavelength is 0.18 pm.The standard deviation of the absolute value of the error is 0.52 pm.Therefore,the MG-Y laser can be used as a stable light source for the fiber grating sensing system.【Conclusion】It is verified by experiments that the traditional manual search for each phase tuning region needs at least 30 min to find the centroid point.The same operation can be completed by KMeans clustering model method,which can greatly shorten the time to find the centroid point.Based on this method,the stable wavelength of quasi-continuous tuning can be achieved by controlling the MG-Y laser.