基于飞秒激光制备的啁啾倾斜布拉格光纤光栅  

Fabrication of Chirped and Tilted Fiber Bragg Gratings with Femtosecond Laser

作　　者：李昊[1,2] 王蒙 武柏屹 叶新宇 高晨晖 饶斌裕 田鑫 奚小明 陈子伦 王泽锋 陈金宝[1,2] Li Hao;Wang Meng;Wu Baiyi;Ye Xinyu;Gao Chenhui;Rao Binyu;Tian Xin;Xi Xiaoming;Chen Zilun;Wang Zefeng;Chen Jinbao(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,Hunan,China;Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,Hunan,China)

机构地区：[1]国防科技大学前沿交叉学科学院,湖南长沙410073 [2]国防科技大学南湖之光实验室,湖南长沙410073

出　　处：《光学学报》2023年第5期259-262,共4页Acta Optica Sinica

基　　金：国家自然科学基金(11974427,12004431);湖南省科技创新计划项目(2021RC4027);脉冲功率激光国家重点实验室主任基金(SKL2020ZR05,SKL-2021-ZR01)。

摘　　要：啁啾倾斜布拉格光纤光栅(CTFBG)在高功率光纤激光器的受激拉曼散射(SRS)抑制中有重要的应用。利用飞秒激光在纤芯/包层直径为20/400μm的大模场面积双包层光纤(LMA-DCF)中刻写出不同角度的CTFBG,其最大滤除深度约为15 dB,最大滤除宽度约为8.9 nm。飞秒激光刻写CTFBG可以显著缩短制备周期,对推动CTFBG的研制与发展具有重要意义。Objective Up to now,high-power fiber lasers have been widely used in industrial processing,national defense,scientific research,and other fields.However,stimulated Raman scattering(SRS)is one of the main factors limiting the power scaling of such fiber lasers.In recent years,chirped and tilted fiber Bragg gratings(CTFBGs)have been demonstrated to suppress the SRS in high-power lasers by filtering the Raman light.CTFBGs are traditionally fabricated by the ultraviolet laser phase mask method,which requires the fibers to be hydrogen-loaded and thermal-annealed before and after grating inscription,respectively.This process is time-consuming and costly,especially when CTFBGs are fabricated with large-core fibers since the time for hydrogen loading and thermal annealing increases as the fiber core expands.The development of the femtosecond(fs)laser inscription method provides an alternative to the fabrication of CTFBGs.As it has no requirement on fiber photosensitivity,hydrogen loading and thermal annealing are no longer necessary,which greatly shortens the fabrication period of CTFBGs.However,although chirped FBGs and tilted FBGs have been fabricated by fs-lasers,fs-laser-inscribed CTFBGs have not been reported yet,and this paper is expected to fill this research gap.Method The inscription system for CTFBGs is shown in Fig.1.The fs-laser emitted from the laser source is reflected by a reflecting mirror and is then focused on a fiber after passing through a chirped phase mask and a cylindrical lens successively.The fiber is fixed on a piezoelectric platform by a pair of fiber holders,and the reflecting mirror and the cylindrical lens are fixed on a one-dimension translation stage.Because the waist width of focal spot is smaller than the diameter of the fiber core,a tilted grating structure can be obtained by the oblique scanning of the fiber with the piezoelectric platform.Moreover,a larger chirp and a longer grating length can be achieved by moving the translation stage along the fiber axis.Results and Discussions Fou

关 键 词：光栅 飞秒激光 光纤光栅 啁啾倾斜布拉格光纤光栅 

分 类 号：TN248[电子电信—物理电子学]