Femtosecond laser direct-writing FBGs achieve kilowatt-level output power in all-fiber oscillator
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摘要:
运用飞秒激光逐面直写技术,结合光束整形方法,成功实现了一步直写大面积光栅栅面。基于该方法在20/400 μm双包层光纤中成功制备高低反光栅对,并用于搭建全光纤振荡器。在
2262 W泵浦功率下实现
1664 W近单模激光输出,光-光转换效率达73.47%,光束质量因子M2=1.46,输出光谱3-dB带宽为3 nm且无受激拉曼散射峰。研究结果表明,飞秒激光直写技术在高功率光栅制备中同时具备工艺灵活性与热管理优势,为全光纤激光器性能提升提供关键技术路径。
Abstract:We have developed a femtosecond laser plane-by-plane direct writing method based on beam shaping, enabling single-step fabrication of the large-area fiber Bragg grating (FBG) planes. Using this innovative approach, we successfully fabricated high-reflectivity (HR) and low-reflectivity (LR) FBG pairs in 20/400-m double-clad fibers and implemented them in an all-fiber oscillator. Under a pump power of
2262 W, the oscillator achieved near-single-mode laser output of
1664 W with an optical–optical conversion efficiency of 73.47%, a beam quality factor M2 of 1.46, and a 3-dB spectral bandwidth of 3 nm without stimulated Raman scattering peaks. The results indicate that femtosecond laser direct writing technology offers both fabrication flexibility and thermal management advantages for high-power grating fabrication, and establishes a key technological pathway for enhancing the performance of all-fiber laser systems.
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