Agilent VEE光纤布拉格光栅波长测试系统

Wavelength test system of FBG based on Agilent VEE

为准确测量光纤布拉格光栅的中心波长,基于Agilent VEE开发环境研制一套自动测试系统,利用可调谐激光器输出光波长精度和信噪比高的特点,通过在光功率计的不同量程档上分别进行波长扫描,并对扫描数据进行融合,系统的测量准确度达到了皮米量级,动态范围达到70 d B以上。在得到光纤布拉格光栅反射光谱曲线的基础上,应用三次样条插值和四次多项式拟合的方法来计算中心波长。测试结果表明:系统的测量重复性优于0.5 pm,测量不确定度为6 pm(k=2),能够满足传感用光纤布拉格光栅的测试需求。

In order to measure the center wavelength of FBG accurately, an automatic test system was developed based on Agilent VEE. By using the advantage of high wavelength accuracy and signal to noise ratio of tunable laser,as well as wavelength sweeping separately at different scale range of optical power meter, the data from the different sweeping were stitched together and the measurement precision was reached to pm magnitude with more than 70 dB dynamic range. Based on the reflected spectrum of FBG, cubic spline interpolation and four-polynomial fitting were applied to calculate the center wavelength. The measuring results show that measurement repeatability is better than 0.5pm, the uncertainty of measurement is 6pm （k=2）, it can fulfill the measuring requirement of FBG which is wildly used in sensing field.