Voropaev Vasilii, Batov Daniil, Mizgirev Semyon, Ivashkina Elena, Belova Valeria, Mkrtchyan Aram, Gladush Yuriy, Krasnikov Dmitry, Nasibulin Albert, Lazarev Vladimir, Tarabrin Mikhail
Opt Express. 2025 Jul 28;33(15):32780-32797. doi: 10.1364/OE.567858.
The increased pulse repetition rate of ultrafast thulium-doped fiber lasers (UTFLs) at a 1.9 μm wavelength can be useful in many applications, including polymer micromachining, intra-volume processing of infrared materials, and surgery. The harmonic mode-locking method allows for a discrete increase in the pulse repetition rate, mainly by increasing the laser power. At the same time, polarization drift over time is an undesirable effect in many applications. However, to date, polarization-maintaining (PM) UTFLs with harmonic mode-locking have not been sufficiently studied. In this paper, to the best of our knowledge, the experimental and numerical study of the PM UTFL operation with harmonic mode-locking up to the 6 order (504 MHz) using polymer-free single-walled carbon nanotubes is carried out for the first time. The generated pulses have a duration of about 400 fs, an average power of 493 mW at a pulse repetition rate of 504 MHz, an energy of 1 nJ, a central wavelength of 1912 nm, and a spectrum width of 7 nm.
波长为1.9μm的超快掺铥光纤激光器（UTFLs）提高脉冲重复频率在许多应用中都很有用，包括聚合物微加工、红外材料的体内加工和手术。谐波锁模方法主要通过增加激光功率来实现脉冲重复频率的离散增加。同时，在许多应用中，随时间的偏振漂移是一种不良效应。然而，迄今为止，对具有谐波锁模的保偏（PM）UTFLs尚未进行充分研究。在本文中，据我们所知，首次使用无聚合物单壁碳纳米管对高达6阶（504MHz）谐波锁模的保偏UTFL运行进行了实验和数值研究。所产生的脉冲持续时间约为400fs，在504MHz的脉冲重复频率下平均功率为493mW，能量为1nJ，中心波长为1912nm，光谱宽度为7nm。
