We demonstrate an all-fiber sub-nanosecond passively mode-locked Tm-Ho co-doped fiber laser. With 1.1-km single-mode fiber (SMF) inserted into the cavity, the laser system can generate 183.4-kHz and 720-ps pulses based on a GaAs saturable absorber (SA). The output spectrum is presented with three wavelengths, which are at 1858.5, 1861.3, and 1864.2 nm, respectively. In addition, with the adjustment of the polarization controller and pump power, the multiple-pulse operation, such as the harmonic mode-locking operation, can also be observed. Higher order of harmonic mode locking is promising but limited by the damage threshold of the SA.

中文翻译：

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亚纳秒多波长谐波锁模Tm-Ho共掺杂光纤激光器

我们演示了全光纤亚纳秒被动锁模Tm-Ho共掺杂光纤激光器。将1.1公里的单模光纤（SMF）插入空腔后，该激光系统可以基于GaAs饱和吸收器（SA）产生183.4 kHz和720 ps的脉冲。输出光谱显示了三个波长，分别为1858.5、1861.3和1864.2 nm。另外，通过调节偏振控制器和泵浦功率，还可以观察到多脉冲操作，例如谐波锁模操作。谐波模式锁定的更高阶是有前途的，但受SA损坏阈值的限制。