近日，国防科技大学马鹏飞团队研究了具有蝙蝠型折射率分布的超千瓦全光纤单频激光放大功能掺镱光纤。相关论文于2025年8月12日发表在《光：科学与应用》杂志上。

具有衍射限制光斑的高功率单频光纤激光器在广泛的光子应用中是必不可少的，特别是在先进的探测和传感技术中。然而，由于受激布里渊散射（SBS）效应和横向模不稳定性（TMI）效应的限制，迄今为止，在所有报道的单频光纤激光系统中，同时实现千瓦级输出功率和衍射限制光束质量仍然遥不可及。

研究组展示了一种具有蝙蝠型折射率分布的超低数值孔径（NA）功能性掺镱光纤的设计和制造，专门用于单频激光放大。在制造过程中，他们实现了多次螯合气体填充和颗粒沉积迭代，从而获得了具有蝙蝠型折射率分布的有源光纤。通过稳定放大输出功率大于1千瓦、光束质量接近单模（M_x²= 1.10, M_x²= 1.18）的单频激光，首次证明了这种大模区高阶模泄漏光纤（HOMLF）的独特性能。这种光纤设计推动了单频光纤激光器的飞跃，它可以作为下一代引力波探测系统的一种新颖有效的激光放大技术。

附：英文原文

Title: Functional Yb-doped fiber with a bat-type refractive index distribution for beyond kilowatt all-fiber single-frequency laser amplification

Author: Li, Wei, Liu, Wei, Deng, Yu, Chen, Yisha, Yang, Huan, Chen, Qi, Zheng, Junjie, Xiao, Hu, Chen, Zilun, Pan, Zhiyong, Ma, Pengfei, Wang, Zefeng, Si, Lei, Xu, Shanhui, Chen, Jinbao

Issue&Volume: 2025-08-12

Abstract: High-power single-frequency fiber lasers with diffraction-limited spots are indispensable for a wide range of photonic applications and are particularly in advanced detection and sensing technologies. However, the simultaneous achievement of kilowatt-level output power and diffraction-limited beam quality has remained elusive in all reported single-frequency fiber laser systems to date, primarily due to limitations imposed by the stimulated Brillouin scattering (SBS) effect and transverse mode instability (TMI) effect. In this study, we demonstrate the design and manufacturing of an ultra-low numerical aperture (NA) functional Yb-doped fiber featuring a bat-type refractive index distribution, specifically engineered for single-frequency laser amplification. In the fabrication, we implemented multiple chelate gas filling and particle deposition iterations, leading to an active fiber with a bat-type refractive index distribution. The unique capabilities of this large mode area and high-order modes leakage fiber (HOMLF) were demonstrated by stably amplifying the single-frequency laser with more than one kilowatt output power and near single mode beam quality (Mx2=1.10, Mx2=1.18) for the first time. This fiber design advances the leap forward in single-frequency fiber lasers, which could contribute as a novel and efficient laser amplification technique for the next generation of gravitational wave detection systems.

DOI: 10.1038/s41377-025-01956-1

Source: https://www.nature.com/articles/s41377-025-01956-1