多模光纤作可饱和吸收体的锁模光纤激光器  

Mode-locked fiber laser with multimode fiber as saturable absorber

作　　者：洪瑶 张靓[1,2] 纪海莹 孙梦茹 王天枢[2,3] Hong Yao;Zhang Jing;Ji Haiying;Sun Mengru;Wang Tianshu(College of Science,Changchun University of Science and Technology,Changchun,Jilin 130022,China;National and Local Joint Engineering Research Center of Space Optoelectronics Technology,Changchun University of Science and Technology,Changchun,Jilin 130022,China;College of Opto-Electronic Engineering,Changchun University of Science and Technology,Changchun,Jilin 130022,China)

机构地区：[1]长春理工大学理学院,吉林长春130022 [2]长春理工大学空间光电技术国家与地方联合工程研究中心,吉林长春130022 [3]长春理工大学光电工程学院,吉林长春130022

出　　处：《光电工程》2021年第5期33-39,共7页Opto-Electronic Engineering

基　　金：国家自然科学基金面上项目(61975021)。

摘　　要：本文报道了一种新兴的锁模方式−多模干涉锁模。这种锁模方式结构简单,搭建方便。在单模光纤激光器中熔接二段短的渐变折射率多模光纤,利用这种单模−多模−单模(SMS)结构的模式干涉效应实现可饱和吸收机制,从而实现锁模脉冲输出。SMS结构实现锁模需要对多模光纤的长度进行精确控制,本文提出将SMS结构缠绕进偏振控制器中,通过理论推导偏振控制器对多模光纤中传输光相位的调控,以实现可饱和吸收效应。在263 mW泵浦功率下实现了24.83 MHz重复频率的传统孤子脉冲输出,其脉冲间隔为40.12 ns,信噪比为50.8 dB,中心波长为1881.7 nm。通过调节偏振控制器和泵浦功率实现孤子分子与传统孤子脉冲的转换。在410 mW的泵浦阈值下实现了25 MHz重复频率的孤子分子脉冲输出,其脉冲间隔为40.3 ns,信噪比为54.4 dB,中心波长为1887.60 nm。We demonstrate a new mode-locking method:multimode interference mode-locking.This method is simple and convenient in construction.It is only necessary to fuse two short pieces of graded-index multimode fiber in a single-mode fiber laser,which uses the mode interference effect of single-mode multimode single-mode(SMS)structure to achieve saturable absorption mechanism.In order to realize the mode-locking of the SMS structure,it is necessary to precisely control the length of multimode fiber.We propose to coil the SMS structure into the polarization controller.By theoretically deriving the polarization controller to adjust the phase of transmission light in a multimode fiber,the saturable absorption effect can be achieved.Under the 263 mV pump power,a stable 24.83 MHz repetition frequency fundamental frequency mode-locked pulse output was realized,where the pulse interval was 40.12 ns,the signal-to-noise ratio was 50.8 dB,and the center wavelength was 1881.7 nm.The conversion between soliton molecules and traditional soliton can be realized by adjusting the polarization controller and pump power.Under the pump threshold of 410 mW,a stable 25 MHz repetition frequency soliton molecular mode-locked pulse output was realized,where the pulse interval was 40.3 ns,the signal-to-noise ratio was 54.4 dB,and the center wavelength was 1887.60 nm.

关 键 词：光纤激光器 锁模激光器 单模-多模-单模光纤结构 非线性多模干涉 

分 类 号：TN248[电子电信—物理电子学]