基于多模光纤干涉效应的百飞秒展宽脉冲产生  

Generation of Stretched Pulse with Hundred-femtosecond Pulse Widths Based on Multimode-fiber Interference Effect

作　　者：孙梦茹 纪海莹 熊浩 洪瑶 马万卓 王天枢[1,2] SUN Mengru;JI Haiying;XIONG Hao;HONG Yao;MA Wanzhuo;WANG Tianshu(National and Local Joint Engineering Research Center of Space Optoelectronics Technology,Changchun University of Science and Technology,Jilin 130022,China;College of Optoelectronics,Changchun University of Science and Technology,Jilin 130022,China)

机构地区：[1]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,长春130022 [2]长春理工大学光电工程学院,长春130022

出　　处：《光子学报》2022年第2期116-124,共9页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.61975021,62005024);吉林省自然科学基金(No.20190201271JC);教育厅项目(No.JJKH20210816KJ)。

摘　　要：设计了基于多模干涉效应锁模的掺铒光纤激光器,利用渐变折射率多模光纤实现了锁模脉冲输出。通过控制泵浦功率,调节腔内偏振控制器,实验获得中心波长为1528 nm的展宽脉冲,3 dB带宽为37.2 nm,脉冲宽度为973.2 fs。在腔外进行色散补偿,将展宽脉冲的脉冲宽度压缩至280.1 fs。此外,通过提高总泵浦功率至961.1 mW并微调偏振控制器,获得了色散管理孤子分子脉冲输出,调制周期为0.32 nm,对应的脉冲间隔为24.1 ps。实验采用多模光纤内置在偏振控制器中的锁模结构,突破了对多模光纤长度的限制,激光器结构紧凑,具有出色的稳定性。Ultrashort pulse fiber lasers have received widespread attention because they play a vital role in telecommunications,biology,and photonics.Many mode-locking technologies have been applied to construct passive mode-locking fiber lasers,such as semiconductor saturable absorption mirrors,graphene,nonlinear polarization rotation,carbon nanotubes,etc.In recent years,researchers have conducted extensive research on multimode fibers and proposed nonlinear multimode interference technology based on multimode fibers for the generation of ultrashort pulses.Compared with traditional mode-locked devices,multi-mode interference-based mode-locked devices have the advantages of high damage threshold,simple structure,adjustable wavelength and controllable modulation depth.In this study,we constructed a multimode interference mode-locked fiber laser by squeezing a piece of GIMF into the polarization controller works as SA.By introducing the dispersion management into the cavity,stretched pulse with 3 dB bandwidth of 37.2 nm was obtained.After compression,these pulses have a hundred-femtosecond duration.By carefully adjusting the PC and increasing the pump power,dispersionmanaged soliton molecules was acquired,and the modulation period of spectrum is 0.32 nm.The experimental setup of the dispersion-managed all-fiber laser based on the SMS structure is depicted in Fig.1.A 0.8 m long piece of single-mode HEDF was utilized as the gain medium,which was pumped by two980 nm LDs through 980/1550 nm WDM.Unidirectional operation was ensured by polarization independent optical isolator.The SA based on the SMS structure in the cavity was used as a mode-locking device,in which a 0.153 m long piece of GIMF was squeezed in the PC and the polarization states of the light in the multimode fiber was changed by tuning the PC.The net cavity dispersion can be managed by using a segment of DCF.In the experiment,the length of DCF is 0.3 m.The GVDs of HEDF,SMF,and DCF at 1.5μm are 15.7,18,and-152.6 ps/nm·km,respectively.Due to the short length of the

关 键 词：光纤激光器 近红外 多模干涉 展宽脉冲 色散管理孤子分子 

分 类 号：TN248[电子电信—物理电子学]