基于非线性光纤环形镜被动锁模掺铒光纤激光器  

Passively Mode-locked Erbium-doped Fiber Laser Based on Nonlinear Fiber Loop Mirror

作　　者：张朝阳 陆宝乐[1,2,3] 陈浩伟 王凯歌[1,2,3] 白晋涛 ZHANG Zhaoyang;LU Baole;CHEN Haowei;WANG Kaige;BAI Jintao(Institute of Photonics&Photon-technology,State Key Laboratory of Energy Photon-technology in Western China,Northwest University,Xi′an 710069,China;International Collaborative Center on Photoelectric Technology and Nano Functional Materials,Northwest University,Xi′an 710069,China;Shaanxi Engineering Technology Research Center for Solid State Lasers and Application,Shaanxi Provincial Key Laboratory of Photo-electronic Technology,Northwest University,Xi′an 710069,China)

机构地区：[1]西北大学光子学与光子技术研究所,省部共建西部能源光子技术国家重点实验室,西安710069 [2]国家级光电技术与纳米功能材料国际联合研究中心,西安710069 [3]陕西省全固态激光及应用工程技术研究中心,陕西省光电子技术重点实验室,西安710069

出　　处：《光子学报》2022年第2期163-169,共7页Acta Photonica Sinica

基　　金：陕西省重点研发计划(No.2020KW-018)。

摘　　要：研究了一种基于非线性光纤环形镜“8”字形谐振腔结构的波长可调谐被动锁模掺铒光纤激光器,该激光器通过将偏振控制器加在耦合比为30/70的2×2光纤耦合器首尾相连的环内,在整个谐振腔的右端搭建了一个Sagnac环形滤波器。当泵浦功率为270 mW时,锁模光纤激光器输出了中心波长为1555.7 nm的传统孤子,其光谱的3-dB带宽为4.2 nm,重复频率为21.1 MHz,信噪比为68 dB,脉冲宽度为0.759 ps。此外,在不改变腔内其他器件的情况下只增加泵浦功率,实现了锁模光纤激光器的连续可调谐,中心波长的调谐范围为1.5 nm;在增加泵浦功率到360 mW时,调节偏振控制器出现了松束缚态孤子。In this paper,a passively mode-locked erbium-doped fiber laser with tunable wavelength of the"8"cavity based on a nonlinear fiber loop mirror is studied.The laser uses a 2×2 coupler with a coupling ratio of30/70 to control a section of the laser with polarization controller.And a Sagnac ring is constructed at the right end of the entire resonant cavity to form a filter.When the pump power up to 270 mW,we tune the polarization controller to achieve a stable mode-locked state,the fiber laser outputs a traditional soliton with a center wavelength of 1555.7 nm,the 3-dB bandwidth of the spectrum is 4.2 nm and the repetition frequency is 21.1 MHz,respectively.The results match the cavity length built in the experiment,the signal-to-noise ratio of the output laser is 68 dB,after fitting the autocorrelation curve of the output pulse,the pulse width is0.759 ps,and the time bandwidth product is 0.397.Collecting the spectrum every 2 hours in the experiment,observe the changes with time of the two peaks of the left and right sidebands closest to the center wavelength in the spectrum and the change of the output power with time during the whole process,and analyze the results to calculate the output.The fluctuation of the power in the course of more than 20 hours is only0.11 mW,which explain the excellent stability of this fiber laser.In addition,we only increase the pump power without moving other components in the cavity,due to the stress of the polarization controller,the single-mode fiber causes the internal unbalanced pressure of the fiber to introduce stress birefringence,and together with PC-2,which forms a filter with a smaller bandwidth and realizes the continuous tunable output of the mode-locked fiber laser.The tuning range of the wavelength interval is 1.5 nm.After increasing the pump power to 360 mW,we adjust the polarization controller to introduce excessive nonlinearity in the laser cavity,the soliton become unstable.Due to the peak power clamping effect,pulse splitting can occur and the modulation period of t

关 键 词：激光器 传统孤子 非线性光纤环形镜 掺铒 被动锁模 

分 类 号：TN248[电子电信—物理电子学]