高功率光纤激光技术

High⁃Power Fiber Laser Technology

高功率光纤技术是目前发展最为迅速的激光技术之一,其在通信、科研、工业、国防等领域有着卓越表现。通过对激光技术发展的研判,上海光学精密机械研究所在国内率先开展光纤激光技术的研究,其中的关键技术主要为高功率窄线宽光纤激光技术和高功率光纤激光合成技术。针对光纤激光的特点,在高功率窄线光纤激光方面,为了抑制非线性效应,逐渐凝练出单频种子光谱调控结合多级放大技术,该技术能够在单光纤激光器功率放大的同时,保持线宽不变并最小化光束质量的劣化。在高功率光纤激光合成方面,同样结合光纤激光的特点,率先开展了全光纤环形腔相干合成(CBC)技术和光谱合成(SBC)技术的研究。近年来,上海光学精密机械研究所在一系列关键技术方面取得了突破性进展,并取得了一系列重要成果。这些成果推动了高功率光纤激光技术的推广和应用,使其成为目前国内外实现高能光纤光源的主流技术。

Significance The high-power fiber laser technology is currently one of the rapidly advancing laser technologies,primarily due to its outstanding performance in various fields,such as communication,research,industry,and defense.Progress Based on the development trend of the laser technology,the Shanghai Institute of Optics and Fine Mechanics(SIOM)took the lead in researching the fiber laser technology in China and decided that two key technologies are the high-power narrow linewidth fiber laser technology and high-power fiber laser beam combining technology.Based on the optical fiber-based laser properties,the narrow-line-width fiber laser output power must be increased to suppress different nonlinear effects.This increase depends on the single frequency seed spectrum modulation combined with the multistage power amplifier technology,which can maintain the spectrum width and realize beam quality during the single-fiber laser power amplification process.For high-power fiber laser beam combining,SIOM first proposed and studied the all-fiber ring cavity coherent beam combining technology and spectral beam combining technology in China.This paper reviews the progress in recent years.SIOM has overcome a series of technical difficulties and achieved a series of achievements,which has driven the promotion and development of these technologies.Conclusions and Prospects In the future,the narrow-line-width fiber laser technology can be used as an effective light source for the development of fiber lasers and beam combining technology.The main problem of nonlinear width fiber laser continues to be nonlinear effects:SBS and TMI.However,these may be improved via three aspects:using the new optical fiber material technology,new spectral modulation technology,and polarized high-power narrow-line-width fiber laser technology.The future demand for higher power and excellent beam quality is expected to be the comprehensive application of different beam combining technologies,complementing each other.Of course,suppressing the nonlinear effect of the laser,developing high-performance devices,and combining cavity structure optimization and beam quality maintenance technology are the basis of the development of the high-energy fiber laser technology.At present,the narrow-line-width fiber laser combined with the laser beam combining technology is the preferred solution of the high-energy light source.