Tang Shihao, Huang Song, Liu Jiayi, Zhou Yong, Zhang Wei, Ma Xiaohui, Fang Wentan, Chen Xiaolin, Luo Yi, Shu Qingbang, Zha Gensheng, Gao Weiqing
Appl Opt. 2025 Jun 20;64(18):5060-5064. doi: 10.1364/AO.560562.
Mid-infrared (MIR) pulsed fiber lasers are widely used because their wavelengths match the molecular fingerprint region and have strong absorption peaks in water. In this work, to our knowledge, the first MIR fiber laser with tunable wavelength and electro-optical Q-switching is demonstrated by using a crystal. The stable Q-switched pulses can be tuned smoothly over a wavelength range of 2705.6-2824.8 nm. The 119.2 nm tuning range is the widest recorded for Q-switched -doped fiber lasers operating around the 2.8 µm band. At a pump power of 3.6 W and a repetition rate of 10 kHz, the laser produces an average output power of 274.5 mW with a pulse width of 17.4 ns. The calculated maximum pulse energy is ∼27.5µ, with a maximum peak power of ∼1.6. Additionally, the signal-to-noise ratio (SNR) is 54 dB, demonstrating excellent pulse stability. The wide tunable range, narrow pulse width, and good stability demonstrate that it is possible to develop an efficient wavelength-tunable MIR pulsed laser using electro-optical Q-switching. These features make it highly promising for applications in laser surgery, polymer processing, and free-space communications.
中红外（MIR）脉冲光纤激光器被广泛应用，因为其波长与分子指纹区域匹配且在水中有强吸收峰。在本工作中，据我们所知，首次通过使用一种晶体展示了具有可调波长和电光调Q的中红外光纤激光器。稳定的调Q脉冲可在2705.6 - 2824.8 nm波长范围内平滑调谐。119.2 nm的调谐范围是在2.8 µm波段附近工作的调Q掺镱光纤激光器所记录的最宽范围。在泵浦功率为3.6 W、重复频率为10 kHz时，该激光器产生平均输出功率为274.5 mW，脉冲宽度为17.4 ns。计算得到的最大脉冲能量约为27.5 µJ，最大峰值功率约为1.6 MW。此外，信噪比（SNR）为54 dB，表明具有优异的脉冲稳定性。宽调谐范围、窄脉冲宽度和良好的稳定性表明，利用电光调Q开发高效的波长可调中红外脉冲激光器是可行的。这些特性使其在激光手术、聚合物加工和自由空间通信等应用中极具前景。
