物理学报2026，Vol.75Issue(7)：235-245,11.DOI:10.7498/aps.75.20251609
被动锁模光纤激光器中倍周期孤子分子调控的研究
Manipulation of period-doubled soliton molecules in a passive mode-locked fiber laser
摘要
Abstract
Passively mode-locked fiber lasers have provided an ideal experimental platform for exploring nonlinear dynamical phenomena,owing to their ability to generate stable optical solitons.The period-doubled solitons,as one of the characteristic indicators of a nonlinear system transitioning from stability to chaos,have attracted considerable research interest.In the period-doubled regime,solitons still circulate at the fundamental cavity round-trip time,while pulse parameters such as pulse energy or peak intensity alternate between two adjacent round trips.So that the pulse state repeats itself only after two cavity round trips.In this work,we experimentally and numerically investigated the manipulation and properties of period-doubled soliton molecules(PDSMs).In the experiment,stable soliton molecules could be obtained when the pump power was set to 18 mW.When the pump power was set to 22 mW,PDSMs with separations of 7.5,15,and 19.5 ps could be obtained by adjusting the polarization controller.By further increasing the pump power to 26 mW and adjusting the polarization controller,period-doubled triple-pulse soliton molecules with equal separations of 13 ps were achieved.These results indicate that pump power and the adjustment of the polarization controller play an important role in the formation of period-doubled soliton molecules.Meanwhile,the dispersive Fourier transform technique was used to observe the real-time evolution of the PDSMs mentioned above in the experiment.It was found that the odd and even pulse energies exhibit a stable intensity difference,while their separations remain consistent.Meanwhile,the phase difference within the soliton molecules was also found to remain unchanged during the period-doubling process,indicating a stable internal phase relationship.The numerical simulation was carried out using a pulse tracing model based on the coupled nonlinear Schrödinger equations,which successfully reproduced the PDSMs phenomena observed in the experiment.The key characteristics,including the oscillation of odd and even pulse energies,the constant separation,and the stable phase-difference evolution,were in good agreement with the experimental results.Both experimental and numerical results indicate that the formation of period-doubled soliton molecules is dominated by the self-phase modulation effect,under the combined action of gain,loss,Kerr nonlinearity,and saturable absorption,leading to a self-consistent dynamical evolution inside the laser cavity.This work helps to reveal the internal dynamics of soliton molecules in mode-locked fiber lasers and the physical mechanisms of period-doubling bifurcations in nonlinear systems.关键词
光纤激光器/孤子分子/倍周期/色散傅里叶变换Key words
fiber laser/soliton molecules/period-doubled/dispersive Fourier transform引用本文复制引用
魏洁楠,胡倩玉,韩冬冬,任凯利,李田甜,惠战强..被动锁模光纤激光器中倍周期孤子分子调控的研究[J].物理学报,2026,75(7):235-245,11.基金项目
国家自然科学基金(批准号:62305268)、陕西省重点研发计划(批准号:2024QY2-GJHX-39)和西安邮电大学电子工程学院交叉学科项目(批准号:XKJC2508)资助的课题. Project supported by the National Natural Science Foundation of China(Grant No.62305268),the Key Research and Development Projects in Shaanxi Province of China(Grant No.2024QY2-GJHX-39),and the Interdisciplinary Research Program of the School of Electronic Engineering,Xi'an University of Posts and Telecommunications,China(Grant No.XKJC2508). （批准号:62305268）
