We report on mode-locked thulium-doped fiber lasers with high-energy nanosecond pulses, relying on the transmission in a semiconductor saturable absorber (SESA) and a carbon nanotube (CNTs-PVA) film separately. A section of an SMF–MMF–SMF structure multimode interferometer with a transmission peak wavelength of ∼2003 nm was used as a wavelength selector to fix the laser wavelength. When the SESA acted as a saturable absorber (SA), the mode-locked fiber laser had a maximum output power of ∼461 mW with a pulse energy of ∼0.14 μJ and a pulse duration of ∼9.14 ns. In a CNT-film-based mode-locked fiber laser, stable mode-locked pulses with the maximum output power of ∼46 mW, pulse energy of ∼26.8 nJ and pulse duration of ∼9.3 ns were obtained. To the best of our knowledge, our experiments demonstrated the first 2 μm region ‘real’ SA-based dissipative soliton resonance with the highest mode-locked pulse energy from a ‘real’ SA-based all-fiberized resonator.

中文翻译：

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具有高能纳秒脉冲的两微米全光纤被动锁模光纤激光器

我们报告了具有高能纳秒脉冲的锁模掺铥光纤激光器，分别依赖于半导体可饱和吸收体 (SESA) 和碳纳米管 (CNTs-PVA) 薄膜中的传输。使用透射峰值波长为~2003 nm的SMF-MMF-SMF结构多模干涉仪的一部分作为波长选择器来固定激光波长。当SESA作为可饱和吸收体（SA）时，锁模光纤激光器的最大输出功率为~461 mW，脉冲能量为~0.14 μJ，脉冲持续时间为~9.14 ns。在基于 CNT 薄膜的锁模光纤激光器中，获得了稳定的锁模脉冲，最大输出功率约为 46 mW，脉冲能量约为 26.8 nJ，脉冲持续时间约为 9.3 ns。据我们所知，