Abstract In this letter, by incorporating hybrid structure of no-core fiber (NCF)-graded index multimode fiber (GIMF) as the saturable absorber (SA) and spectral filter simultaneously, not only the switchable noise-like pulses (NLPs) but also the tunable single- and dual-wavelength dissipative solitons (DSs) are obtained from a net normal dispersion Yb-doped mode-locked fiber laser. The NCF-GIMF device plays a crucial role in the pulse generation and the wavelength tuning. By means of being stretched, the transmission peak of the NCF-GIMF device can be tuned over 60 nm which is responsible for the wavelength tuning of the oscillator. As the SA, the NCF-GIMF device affords variable saturable absorption properties during the stretching process which are suitable for the ultrafast soliton generation. Based on this device, the center wavelengths of the NLPs are demonstrated to be switchable from 1034.6 nm to 1072.2 nm. The single wavelength DSs with the pulse width at the level of tens of picoseconds can be tuned from 1026.3 nm to 1080 nm. Additionally, the dual-wavelength asynchronized DSs with a spectral interval of 21 nm have a wavelength-tunable range of 13 nm. This all-fiber ultrafast Yb-doped laser with tunable and flexible outputs can satisfy diverse application needs.

中文翻译：

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NCF-GIMF 器件作为 SA 和滤波器用于可调谐单波长和双波长掺镱锁模光纤激光器

摘要 在这封信中，通过将无芯光纤 (NCF) 渐变折射率多模光纤 (GIMF) 的混合结构同时用作可饱和吸收器 (SA) 和光谱滤波器，不仅可切换类噪声脉冲 (NLP)，而且可调谐的单波长和双波长耗散孤子 (DS) 是从净法向色散掺镱锁模光纤激光器中获得的。NCF-GIMF 设备在脉冲生成和波长调谐中起着至关重要的作用。通过拉伸，NCF-GIMF 器件的传输峰值可以调谐到 60 nm 以上，这负责振荡器的波长调谐。作为 SA，NCF-GIMF 设备在拉伸过程中提供可变的饱和吸收特性，适用于超快孤子生成。基于此设备，NLP 的中心波长被证明可以从 1034.6 nm 切换到 1072.2 nm。脉冲宽度在几十皮秒级的单波长DS可以从1026.3 nm调谐到1080 nm。此外，光谱间隔为21 nm的双波长异步DS具有13 nm的波长可调范围。这种具有可调和灵活输出的全光纤超快掺镱激光器可以满足各种应用需求。