Revealing the behavior of soliton buildup in a mode-locked laser  

作　　者：Xueming Liu Yudong Cui 

机构地区：[1]Zhejiang University,College of Optical Science and Engineering,State Key Laboratory of Modern Optical Instrumentation,Hangzhou,China [2]Nanjing University of Aeronautics and Astronautics,Institute for Advanced Interdisciplinary Research,Nanjing,China [3]Hunan University of Science and Technology,School of Physics and Electronic Science,Xiangtan,China

出　　处：《Advanced Photonics》2019年第1期58-71,共14页先进光子学（英文）

基　　金：We thank X.Yao,X.Han,G.Chen,W.Li,G.Wang,and Y.Zhang for fruitful discussions.The work was supported by the National Natural Science Foundation of China under Grant Nos.61525505,11774310, 61705193;by the Key Scientific and Technological Innovation Team Project in Shaanxi Province(2015KCT-06);and by China Postdoctoral Science Foundation(2017M610367).

摘　　要：Real-time spectroscopy based on an emerging time-stretch technique can map the spectral information of optical waves into the time domain,opening several fascinating explorations of nonlinear dynamics in mode-locked lasers.However,the self-starting process of mode-locked lasers is quite sensitive to environmental perturbation,which causes the transient behaviors of lasers to deviate from the true buildup process of solitons.We optimize the laser system to improve its stability,which suppresses the Q-switched lasing induced by environmental perturbation.We,therefore,demonstrate the first observation of the entire buildup process of solitons in a mode-locked laser,revealing two possible pathways to generate the temporal solitons.One pathway includes the dynamics of raised relaxation oscillation,quasimode-locking stage,spectral beating behavior,and finally the stable single-soliton mode-locking.The other pathway contains,however,an extra transient bound-state stage before the final single-pulse modelocking operation.Moreover,we propose a theoretical model to predict the buildup time of solitons,which agrees well with the experimental results.Our findings can bring real-time insights into ultrafast fiber laser design and optimization,as well as promote the application of fiber laser.

关 键 词：fiber laser MODE-LOCKING self-starting process relaxation oscillation real-time spectroscopy 

分 类 号：TN248[电子电信—物理电子学]