闫丽 1,2,3林启蒙 1,2,3宋园起 1,2,3贾谞卓 1,2,3[ ... ]江曼 1,2,3,*
1 西北大学 光子学与光子技术研究所,西安 710127
2 西北大学 陕西省光电子技术重点实验室,西安 710127
3 西北大学 省部共建西部能源光子技术国家重点实验室,西安 710127
报道了一种基于非线性光纤的宽光谱类噪声锁模掺铒光纤激光器。在非线性偏振旋转锁模掺铒光纤激光谐振腔内引入色散补偿光纤和高非线性光纤,实现腔内色散和非线性管理,最终获得稳定的锁模脉冲输出。当在谐振腔内引入6 cm高非线性光纤时,可以获得中心波长为1 534 nm,脉冲宽度为1.9 ps,重复频率为20.1 MHz,40 dB光谱带宽约为100 nm的超短脉冲输出。在此基础上,将高非线性光纤长度增加至30 cm时,通过优化波片角度,观察到稳定的类噪声锁模脉冲输出,其输出光谱覆盖范围为1 280~1 850 nm,40 dB带宽为500 nm,尖峰脉冲宽度短至70.9 fs,基座脉冲宽度为26.6 ps,重复频率约19.7 MHz。同时在实验中发现随着泵浦功率的提高,类噪声脉冲的基座脉宽和尖峰脉宽的演化呈相反趋势,光谱覆盖范围更宽。该类噪声锁模光纤激光器的研究对低相干光谱干涉技术的发展具有重要意义。
宽光谱 高非线性光纤 色散 类噪声脉冲 非线性偏振旋转锁模 Broad spectrum Highly nonlinear fiber Dispersion Noise-like pulse Nonlinear polarization rotation mode-locking
淮北师范大学物理与电子信息学院,安徽 淮北 235000
报道了L波段掺铒光纤激光器中调Q锁模类噪声方波脉冲的演化特性。通过改变泵浦功率以及偏振状态,激光器可以在1600 nm处实现类噪声方波脉冲的连续波锁模和调Q锁模运作。类噪声方波脉冲基频锁模重复率为1.64 MHz,最大脉冲宽度为17.51 ns。类噪声方波脉冲调Q锁模的重复率可从8.14 kHz调谐至18.18 kHz,调Q锁模包络宽度与方波脉冲宽度随泵浦功率演化趋势相反,调Q包络的最高平均能量可达1115.5 nJ,包络内方波脉冲的最大平均能量可达24.89 nJ,方波脉冲的峰值功率维持在1 W左右。该实验结果有助于人们深入理解L波段调Q锁模类噪声方波脉冲的动力学特性。
激光器 光纤激光器 非线性偏振旋转 类噪声方波脉冲 调Q锁模 激光与光电子学进展
2022, 59(13): 1314003
Author Affiliations
Abstract
School of Physics and Optoelectronics, Faculty of Science, Beijing University of Technology, Beijing 100124, China
The dispersive Fourier transform technique provides feasibility of exploring non-repetitive events and the buildup process in ultrafast lasers. In this paper, we report a new buildup process of dissipative solitons in a simplified mode-locked Yb-doped fiber laser, which includes more complex physics stages such as the Q-switching stage, raised and damped relaxation oscillation stages, noise-like stage, successive soliton explosions stage, and soliton breathing stage. Complete evolution dynamics of noise-like pulse and double pulse are also investigated with dispersive Fourier transform. For the noise-like pulse dynamics process, it will only experience the Q-switching and relaxation oscillation stages. In the case of dissipative soliton and noise-like pulse, the double pulse buildup behavior is manifested as the replication of individual pulses. A weak energy migration occurs between two pulses before reaching steady state. Meanwhile, real-time mutual conversion of the dissipative soliton and noise-like pulse has been experimentally observed, which appears to be instantaneous without extra physical processes. To the best of our knowledge, this is the first report on these physical phenomena observed together in a mode-locked fiber laser. The results further enrich the dynamics of mode-locked fiber lasers and provide potential conditions for obtaining intelligent mode-locked lasers with controllable output.
dispersive Fourier transform dynamics process simplified mode-locked fiber lasers dissipative soliton noise-like pulse double-pulse Chinese Optics Letters
2022, 20(8): 081402
Author Affiliations
Abstract
1 Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, China
2 College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, China
A stable noise-like (NL) mode-locked Tm-doped fiber laser (TDFL) relying on a nonlinear optical loop mirror (NOLM) was experimentally presented. Different from the previous NL mode-locked TDFL with NOLM, the entire polarization-maintaining (PM) fiber construction was utilized in our laser cavity, which makes the oscillator have a better resistance to environmental perturbations. The robust TDFL can deliver stable bound-state NL pulses with a pulse envelope tunable from ~14.1 ns to ~23.6 ns and maximum pulse energy of ~40.3 nJ at a repetition rate of ~980.6 kHz. Meanwhile, the all-PM fiber laser shows good power stability (less than ~0.7%) and repeatability.
noise-like pulse all-polarization-maintaining fiber nonlinear loop mirror Tm-doped fiber laser Chinese Optics Letters
2021, 19(9): 091402
Author Affiliations
Abstract
1 College of Physics and Optoelectronics, Faculty of Science, Beijing University of Technology, Beijing 100124, China
2 Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
Noise-like pulses having a pedestal of 690 fs and a spike of 59.6 fs were generated in a nonlinear Yb-doped fiber amplification system. The seed source is a mode-locked Yb-doped fiber laser by nonlinear polarization rotation, and dissipative soliton pulses were obtained in it. Then, the dissipative soliton pulses passed through a 7.6 m dispersive fiber to enhance the dispersion and nonlinearity. Further on, the dissipative soliton pulses were launched into a Yb-doped fiber nonlinear amplifier, and stable noise-like pulses with a pedestal of 6.26 ps and a spike of 227 fs were achieved. Finally, by a grating pair, the pedestal and spike of the noise-like pulses were effectively compressed to 690 fs and 59.6 fs, respectively. To the best of our knowledge, this is the shortest pedestal demonstrated in noise-like pulses operating at 1 μm.
fiber laser amplifier compression noise-like pulse Chinese Optics Letters
2020, 18(12): 121403
1 厦门大学嘉庚学院 信息科学与技术学院,福建 漳州 363105
2 长春理工大学 空间光电技术国家地方联合工程研究中心,吉林 长春 130022
设计了一种基于色散管理的掺铥光纤激光器。通过调节泵浦功率以及腔内偏振态,首先实现了稳定的展宽脉冲输出,中心波长和脉冲宽度分别为1 939.4 nm和482 fs。最大输出功率为15 mW,对应的单脉冲能量为0.52 nJ。增加泵浦功率到645 mW时,通过适当调节偏振控制器可以实现类噪声脉冲锁模,中心波长为1 940.1 nm。所实现的锁模脉冲具有飞秒量级的尖峰以及皮秒量级的基底。最大输出功率为20.4 mW,相对应的单脉冲能量为0.7 nJ。相比于传统孤子,采用色散管理所实现的锁模脉冲具有更高的脉冲能量。此外,所设计的掺铥光纤激光器可作为理想的主振荡功率放大以及啁啾脉冲放大结构的种子源,进一步提高脉冲能量,拓展2 μm高能光纤激光器的实际应用。
掺铥光纤激光器 色散管理 展宽脉冲 类噪声脉冲 Tm-doped fiber laser dispersion management stretched-pulse noise-like pulse
中国科学技术大学光学与光学工程系, 安徽 合肥 230026
报道了一种全光纤超宽带光谱的类噪声脉冲锁模光纤激光器。为了加宽锁模光谱,利用腔内色 散管理和非线性技术使光脉冲在58 m腔内具有小的反常色散,平均色散系数为0.12 ps/nm/km。 实验获得了1300~1750 nm超宽带光谱锁模类噪声脉冲,光谱20 dB带宽达到362 nm, 3 dB带宽达到102 nm, 类噪声脉冲光谱宽度远超过掺铒光纤的增益带宽。
激光技术 类噪声脉冲 锁模激光器 光纤激光器 laser techniques noise-like pulse mode-locked lasers fiber lasers
江苏师范大学物理与电子工程学院江苏省先进激光材料与器件重点实验室, 江苏 徐州 221116
采用数值分析的方法研究了光纤激光器中类噪声脉冲的自相关特性。数值计算的结果复现了实验中观测到的类噪声自相关曲线图形。进一步改变类噪声脉冲各参量设置,发现无背景强度自相关曲线的基底和尖峰的宽度分别反映了类噪声脉冲波包的宽度以及类噪声脉冲波包中超短脉冲的平均脉宽。相同的类噪声脉冲波包中超短脉冲的个数越多,无背景强度自相关曲线的尖峰与基底的峰值比越小,尖峰与基底的宽度则不受影响。对类噪声脉冲干涉自相关曲线的数值研究结果表明,实验中测量得到的峰值背景比小于8∶1 的干涉自相关曲线,是类噪声脉冲波包宽度、类噪声脉冲啁啾、自相关仪扫描范围共同影响的结果。
非线性光学 类噪声脉冲 二阶自相关 光纤激光器 数值模拟 激光与光电子学进展
2015, 52(12): 121902