掺镱多模双包层光纤激光器弯曲选模研究

Research of mode selection in a coiled Yb^(3+) doped multimode double clad fiber laser

为了使大芯径多模双包层光纤激光器实现基模输出以抑制高功率双层光纤激光器中的非线性效应,采用将大芯径的多模双包层光纤适当弯曲进行选模使双包层光纤激光器获得单模激光输出的方法,进行了理论分析和实验验证,取得了大芯径多模双包层光纤内包层折射率、纤芯半径、光纤内传输信号光波长、光纤弯曲半径等因素对弯曲损耗及激光器输出光场模式影响的数据,并采用国产掺镱多模双包层光纤进行了弯曲选模实验,实现了多模光纤激光器的单模输出。结果表明,激光器最大输出功率达9W,斜率效率达17.3%,输出为基模。这一结果对大芯径多模双包层光纤激光器的选模是有帮助的。

In order to realize the monomode output in large core multimode double-clad fiber laser to suppress the nonlinear effects in high power double-clad fiber lasers,mode selection by bending the large core multimode double-clad fiber to a suitable radius was used. Theoretical analysis and experiments about mode selection in large core multimode double-clad fiber laser were demonstrated in this paper. Factors that influence the laser bending loss and output mode, such as inner-clad refractive index, core radius,laser wavelength, bending radius ,were obtained. Monomode output was obtained from multimode double-clad fiber laser by bending the homemade Yb3^-doped large core multimode fiber. The laser has a fundamental mode output with power of 9W, conversion efficiency of 17.3%. The research is useful in mode selection from large core multimode double-clad fiber laser.