Theory and Experiment of Increasing the Extinction Ratio of the Cascaded Long Period Gratings Utilizing the Fiber Loop Mirror
利用光纤环形镜提高级联长周期光栅干涉谱消光比的理论和实验分析

The interferometric spectrum of the cascaded long period gratings (LPG) has been modulated, and it is presented that the extinction ratio can be doubled when a fiber loop mirror is connected at the end of the cascaded LPGs, which has been proved by the experiment. The fiber loop mirror is indeed an effective and simple way to increase the extinction ratio.