论文部分内容阅读
采用单端连续抽运方式,对自由运转的双包层掺镱光纤激光器的输出特性进行了详细的实验研究.实验中不但观察到了自脉冲,而且首次在自由运转的光纤激光器中观察到自锁模现象,对它们产生的物理机理进行了相应的理论分析.分析表明:增益光纤的弱(未)抽运部分对信号光的吸收导致光纤激光器内自脉冲的出现,轴向模之间的拍频和自相位调制导致自锁模现象的出现,而受激拉曼散射、受激布里渊散射等非线性效应使它们进一步增强.当抽运光功率略高于阈值时,自脉冲宽度比较宽,随抽运光功率增加自脉冲的脉宽变窄;自脉冲包络面内的自锁模脉冲的宽度随抽运光功率增加也变窄,进一步增加抽运光功率,自脉冲和自脉冲包络面内的自锁模现象消失.实验测得自锁模脉冲的间隔为224 ns,最大(小)自锁模脉冲的半高全宽约为35.0 ns(6.3 ns);测得信号光的中心波长为1090nm,谱线半高全宽的最大(小)值约为7.05 nm(2.01 nm).
The output characteristics of a double-clad Yb-doped fiber laser using a single-ended continuous pumping method are studied in detail.It is not only self-pulse but also the first time that a self-locking fiber laser is observed in a free-running fiber laser Mode phenomenon, the corresponding theoretical analysis of their physical mechanism is made.The analysis shows that the absorption of signal light by the weak (un) pumping part of the gain fiber leads to the appearance of self-pulse in the fiber laser, the beat between the axial modes Frequency and self-phase modulation lead to the occurrence of self-mode-locking phenomena, which are further enhanced by nonlinear effects such as stimulated Raman scattering and stimulated Brillouin scattering. Since the pump power is slightly above the threshold, The width of the self-mode-locked pulse in the envelope of the self-pulse is also narrowed with the increase of the pumping light power, which further increases the pumping light power. The pulse self-pulse and the self- The self-mode-locked phenomenon vanishes in the envelope of the pulse, and the interval of the self-mode-locked pulses is 224 ns. The full-width at half maximum of the largest self-mode-locked pulse is about 35.0 ns (6.3 ns) The center wavelength is 1090nm, The maximum (minimum) full width at half maximum of the spectrum is about 7.05 nm (2.01 nm).