基于相位掩模板的常规光纤制备弱反射光栅  

Fabrication of weak fiber Bragg grating with conventional fiber based on phase mask

作　　者：顾宏灿[1] 姚高飞 黄俊斌[1] 丁朋 GU Hongcan;YAO Gaofei;HUANG Junbin;DING Peng(Department of Weapon Engineering, Naval University of Engineering, Wuhan 430033, China)

机构地区：[1]海军工程大学兵器工程学院,武汉430033

出　　处：《激光技术》2022年第2期149-154,共6页Laser Technology

基　　金：国家自然科学基金资助项目(11774432)。

摘　　要：为了探索采用常规单模光纤制备弱反射光纤光栅的可行性,以降低材料成本和传输损耗,基于相位掩模板法,在常规单模光纤上刻制弱反射光纤布喇格光栅(WFBG),并进行了实验验证。建立相位掩模板刻栅系统光场统一方程,分析光场分布对光纤布喇格光栅(FBG)中心波长和反射率的影响;采用传输矩阵法分析相位掩模板长度、平均折射率变化对FBG反射率和3dB带宽的影响,为WFBG刻制提供理论依据。采用248nm紫外准分子激光器在常规单模光纤上刻制WFBG,分析相位掩模板长度、曝光能量、曝光频率,曝光次数对WFBG中心波长、反射率和3dB带宽的影响,制备出反射率和3dB带宽分别约为0.0016,0.10nm和0.00006,0.34nm两种窄宽的WFBG。结果表明,基于相位掩模板法由紫外准分子激光对常规单模光纤多脉冲曝光,能够稳定刻制WFBG。该研究对WFBG制备的材料选型提供了参考。In order to explore the feasibility of using conventional fiber to fabricate weak fiber Bragg grating(WFBG)and reduce the material cost and transmission loss,a WFBG was fabricated on a conventional single-mode fiber(CSMF)based on phase mask method.The unified optical field equation of phase mask grating system was established,and the influence of optical field distribution on center wavelength and reflectivity of FBG was analyzed.The influence of phase mask length and average change of refractive index on reflectivity and 3dB bandwidth of FBG was analyzed by transfer matrix method,which provides theoretical basis for improving WFBG lithography.WFBGs were fabricated on CSMFs by 248nm UV excimer laser.The effects of phase mask length,exposure energy,exposure frequency,and exposure times on central wavelength,reflectivity,and 3dB bandwidth of WFBG were respectively analyzed.Two kinds of WFBGs with narrow and wide bandwidths were fabricated with reflectivity and 3dB bandwidth of 0.0016 and 0.10nm,0.00006 and 0.34nm,respectively.Theoretical and experimental results show that WFBG can be fabricated on CSMF stably by the multi-pulse exposure of UV excimer laser based on the phase mask method,which provides a reference for the material selection of the weak reflection fiber grating.

关 键 词：光纤光学 弱反射光纤布喇格光栅 相位掩模板 单模光纤 衍射光场 

分 类 号：TN253[电子电信—物理电子学]