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。

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.

为了获得基于孤子自频移效应的1.6 μm波段锁模脉冲，设计了一种非线性偏振旋转的掺铒光纤激光器，并利用双输出结构检测脉冲。在泵浦功率为350 mW时，通过适当调节偏振控制器，同时在两个输出端观察到中心波长为1560 nm的类噪声脉冲，3 dB带宽为17.5 nm，脉冲持续时间为968 fs。进一步将泵浦功率增加至550 mW，输出端1的类噪声脉冲保持不变，输出端2的类噪声脉冲的中心波长红移至1614 nm，3 dB带宽增加至64.4 nm，脉冲持续时间减小至302 fs。谐振腔的最大输出功率为11.4 mW。同时，实验分析了色散位移光纤的长度对孤子自频移的影响，结果表明，在一定范围内，色散位移光纤的长度越长，孤子自频移的频移间距越小。实验研究的1.6 μm波段光纤激光器在光学通信领域具有潜在的应用价值。

设计了一种由类噪声脉冲抽运的全光纤结构平坦超连续谱光源。在色散管理掺铒光纤激光器中通过调节腔内偏振态，在泵浦功率为450 mW时，实现了稳定的类噪声脉冲锁模，锁模脉冲的中心波长为1 600 nm，脉冲宽度为303 fs。在最大泵浦功率为1 W时，谐振腔直接输出功率为8.6 mW。较低的功率无法有效拓展超连续谱宽度，为此设计一种掺铒光纤放大器进行功率放大，放大器最大输出功率为338 mW，将功率放大后的类噪声脉冲耦合进高非线性光纤以产生超连续谱，超连续谱的20 dB光谱范围为1 530 nm～2 300 nm，在1 736 nm～2 134 nm范围内，光谱的平坦度优于0.5 dB。

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 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.