基于全光纤梳状滤波器的被动锁模激光器性能研究  

Performance of Passive Mode-Locked Lasers Based on All-Fiber Comb Filters

作　　者：张梦 李慧铮 Zhang Meng;Li Huizheng(Optoelectronics Laboratory,School of Electronic and Information Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学电子信息工程学院光电实验室,北京100191

出　　处：《中国激光》2022年第19期110-119,共10页Chinese Journal of Lasers

摘　　要：滤波效应对脉冲的形成、波形调控和动态传输有重大的影响。展示了一种以全光纤马赫-曾德尔干涉仪作为紧凑梳状滤波器的多功能掺铥光纤激光器,实现了多波长连续激光输出、多波长锁模激光脉冲输出,在1842~1898 nm光谱范围内可调谐输出单波长锁模激光并同时获得四波长锁模脉冲。采用拉锥技术制备了全光纤微结谐振器,在掺铒光纤激光器腔中,获得了束缚态孤子,且锁模状态可实现从基频状态到谐波锁模的切换。通过调控谐振腔功率以及偏振状态,实现了24阶谐波锁模,其脉冲形态仍是束缚态孤子。实验结果以及数值分析结果表明,滤波效应对脉冲形态有显著的影响。Objective Fiber-comb filters demonstrate significant application potentials in ultrafast optics,optical information processing,fiber sensing,laser processing,and laser guidance.As a class of fiber-laser control devices,filters play an irreplaceable role in laser generation,soliton formation,and pulse-waveform control,which are essential components of tunable,narrow-bandwidth,and multi-wavelength fiber lasers.Therefore,studying the effect of filtering on pulse generation and transmission and manufacturing new filter devices are valuable.Methods In the experiments,first,a Mach--Zehnder interferometer(MZI)is developed by connecting two arms with two 3 dB couplers through fiber splicing.The fabricated MZI is then incorporated into a laser cavity.The laser cavity adopts a hybrid cavity mode-locking method that combined nonlinear polarization rotation(NPR)and few-layer black phosphorus(BP).Second,the ultrafine fiber is extracted from the standard single-mode fiber(SMF)via the flame brush technique,the tapered fiber is knotted,and the fabricated micro-knot resonator(MKR)is obtained.The fabricated MKR is then incorporated into the laser cavity.The laser cavity is mode-locked using a real saturable absorber.Results and Discussions Based on the MZI multi-wavelength mode-locked fiber laser,when the pump power reaches 270 mW,a multi-wavelength continuous laser output is generated(Fig.4).To obtain different pulse states,we increase the pump power to 327 mW and adjust the polarization controller(PC)to realize single-wavelength locking(the central wavelength is adjustable)(Fig.5).The NPR suppresses mode competition and introduces the filtering effect.The modulation depth of the sample MZI is large;thus,multi-wavelength mode-locked laser sequences are realized at room temperature.A dual-wavelength mode-locked laser is obtained by increasing the power to 400 mW(Fig.6).Threewavelength mode-locked lasers with different distance intervals are obtained by further increasing the power to 420 mW(Fig.7).The interval between two adjacent

关 键 词：激光器 锁模激光器 多波长锁模激光器 滤波效应 梳状滤波器 束缚态孤子 

分 类 号：TN248[电子电信—物理电子学]