基于随机相移光栅的主动调Q随机光纤激光器的脉冲特性及其演化规律  

Pulse Characteristics of Actively Q⁃Switched Random Fiber Laser Based on Random Phase Shift Grating and Their Evolution

作　　者：张爱玲[1,2,3] 孙澳 甄超凡 陈镐哲 石艳梅[1,2,3] Zhang Ailing;Sun Ao;Zhen Chaofan;Chen Haozhe;Shi Yanmei(School of Integrated Circuit Science and Engineering,Tianjin University of Technology,Tianjin 300384,China;Engineering Research Center for Optoelectronic Devices and Communication Technology,Ministry of Education,Tianjin University of Technology,Tianjin 300384,China;Tianjin Key Laboratory of Thin Film Electronics and Communication Devices,Tianjin University of Technology,Tianjin 300384,China)

机构地区：[1]天津理工大学集成电路科学与工程学院,天津300384 [2]天津理工大学光电器件与通信技术教育部工程研究中心,天津300384 [3]天津理工大学天津市薄膜电子与通信器件重点实验室,天津300384

出　　处：《中国激光》2024年第18期133-141,共9页Chinese Journal of Lasers

基　　金：教育部新世纪优秀人才支持计划(NCET-07-0611)。

摘　　要：重点阐述了基于随机相移光栅的主动调Q随机光纤激光器(RFL)的脉冲特性及其演化规律,比较了环形腔和线形腔主动调Q随机光纤激光器的时域脉冲特性。结果表明:在环形腔随机光纤激光器中,通过调控泵浦功率和电光调制器(EOM)的调制频率,能够获得倍周期、双脉冲、三脉冲、混沌脉冲等不同的脉冲状态;在线形腔随机光纤激光器中,同样观察到了与环形腔随机光纤激光器变化规律一致的脉冲分裂和倍周期现象,外部光注入除了会改变脉冲形状之外,不会从根本上改变脉冲的演化规律。主动调Q随机光纤激光器的脉冲特性是可调控的,其在生物模拟和加密通信中具有潜在的应用前景。Objective Owing to the wide application of Q-switched random fiber lasers(RFLs)in numerous fields,such as medical and information encryption,the pulse characteristics and evolution of RFLs should be investigated comprehensively.Hence,the pulse characteristics and evolution of actively Q-switched random fiber lasers based on a random-phase-shift fiber Bragg grating(RPS-FBG)are investigated in this study.The pulse characteristics of the actively Q-switched RFLs with ring and linear cavities are compared.Results show that in the ring-cavity RFL,different pulse states such as multi-period,splitting,and chaotic pulses are obtained by adjusting the pump power and modulation frequency of the electro–optic modulator(EOM).In the linear-cavity RFL,pulse splitting and multi-period phenomena are similarly observed,which is consistent with the evolution of the ring-cavity RFLs.Moreover,external laser injection does not change the pulse evolution but only reduces the number of splitting pulses and generates a weak dark pulse.Methods Actively Q-switched RFLs with ring(Fig.1)and linear cavities(Fig.9)are investigated experimentally.The effects of pump power,EOM frequency,and external laser injection on the pulse characteristics of the RFLs and their evolution are analyzed.A photodetector(bandwidth of 200 MHz)and an oscilloscope(sampling rate of 2 GSa/s)are used to measure the pulse train of the RFLs,and an optical spectrum analyzer is used to characterize the RFL spectra.Results and Discussions For the ring-cavity RFL,when the modulation signal is fixed,the output pulse is varied from a multiperiod state to a single-period state and then to a pulse-splitting state with a chaotic state among different pulse-splitting states as the pump power increases(Fig.3),while its spectrum remains relatively constant(Fig.4).For example,the P-1/2 state is achieved at a pump power of 50 mW,whereas the P-1/1 state is obtained at a pump power of 80 mW.At pump powers of 140,200,240,and 270 mW,the pulse state evolves sequentially into the P-2/1,P

关 键 词：主动调Q 随机光纤激光器 随机相移光栅 脉冲特性 电光调制器 

分 类 号：O436[机械工程—光学工程]