改进型Sagnac干涉系统刻写光纤光栅的实验设计

Experiment Design for Writing Fiber Grating Based on Improved Sagnac Interference System

建立了基于改进型Sagnac干涉系统刻写光纤光栅的实验平台。与传统相位掩膜法不同,该平台的+1和-1级衍射光是分开后再通过反射镜两次反射叠加干涉,因而光纤不需要紧靠相位掩膜版,可在合适的空间处获得干涉条纹,实验操作方便。该平台无需更换相位掩膜版,只调整反射镜改变干涉角度就可获得不同光栅中心波长。结合实例,设计了刻写硫系玻璃光纤布拉格光栅实验,探究影响光栅质量的主要因素。

Aiming at the theoretical courses of fiber gratings and their wide applications for various aspects of engineering and scientific research in the fields of fiber communication and sensors,and by combining with scientific research,an experimental platform based on a improved Sagnac interference system for writing fiber grating is designed and established.Being different from the traditional phase mask method,the+1st and-1st order diffracted light beams of this platform are separated,and then reflected twice through the mirrors to superimpose and produce interference,so the fiber does not need to be close to the phase mask,and can be obtained the interference fringe in a suitable space,which makes the operation easy.In addition,for obtaining different grating center wavelengths,this platform does not need to change the phase mask,only needs to adjust the mirrors to change the interference angle.Combined with examples,an experiment for writing chalcogenide glass fiber Bragg gratings is designed to explore the main factors affecting the quality of the grating.