利用全光纤Mach-Zehnder干涉仪对二极管激光器瞬态特性进行表征

可调谐二极管激光器在电流调谐过程中的瞬态特性,包括瞬态输出波长和线宽等光学参数,在TDLAS系统中是一个重要的参数需要进行实时准确的测定。而常规的测量方法无法同时满足高精度与高速度的要求,因此,对短光纤延迟差拍法测量TDL的动态特性进行了理论分析和实验研究,搭建测试系统,确定了光纤延迟线长度与调谐率对差拍信号纯度的影响,并分别对DFB型TDL的动态调谐特性进行了实时测量,由差拍信号得到激光器在一个电流调谐周期内对应于不同注入电流的瞬态输出波长及其线宽,即电流调谐瞬态特性。实验结果与由光谱仪测得静态特性比较后发现两者误差在0.003nm范围内,光纤延时自外差法可以对TDL瞬态特性进行快速实时而准确的监测。将其应用于TDLAS系统可提高测量精度,且可以根据监测的瞬态特性最终实现对TDL实时监控与优化。

Measurement of the Transient Tuning Characteristicsof Tunable Diode Laser Based on All-Fiber Mach-Zehnder Interferometer

The tuning characteristics of tunable diode laser include parameters such as transient output wavelength and line width.The parameters are very important and should be measured with real-time accuracy in TDLAS.But regular measurement cannot measure its quality of accuracy and high speed.This paper studies theoretically and experimentally of TDL dynamic characteristics of the short fibers delay beat,With the establishment of a testing system,it discovers the influence of time delay line length and tuning rate to beat signal purity,it also makes real-time measurement for the dynamic tuning characteristics of DFB TDL,thus getting the laser transient output wavelength and line width of different currents by the result of beat signal in a current tuning cycle,namely,current transient tuning characteristics.The result difference is within 0.003nm compared with the static characteristic from spectrometer measuring.Fiber Delay Self-heterodyne can quickly,accurately and real-timely monitor TDL transient characteristics.The measuring precision is increased when it is applied to TDLAS system,realizing TDL real-time monitoring and optimization according to monitoring transient characteristics.