滤波位置相关的全正色散掺Yb^(3+)锁模光纤激光器的实验研究

Experimental study on all-normal-dispersion mode-locked fiber laser with optimal spectral filtering position

采用非线性偏振旋转锁模,构建了一种全正色散掺Yb3+光纤环形激光器.在该激光腔内采用了10nm带宽的光纤滤波器提供附加的自振幅调制.通过改变滤波器在腔内的位置,实验证明了滤波器位置对高啁啾脉冲的整形过程起到重要的作用.在320mW的抽运功率下,最终获得平均功率为92.2mW,脉冲重复频率为26.6MHz,脉冲宽度为6.2ps的稳定脉冲输出,单脉冲能量达3.5nJ的优化结果.通过数值模拟与实验结果的验证表明,两者相符很好.

Employing nonlinear polarization rotation,an all-normal-dispersion mode-locked fiber ring laser was constructed,in which a fiber filter with 10 nm bandwidth was used in the cavity to provide the additional self-amplitude modulation. The important role of the filter position plays in the high-chirped pulse shaping in the laser has been experimentally demonstrated by choosing different locations of the filter in the cavity. A mode-locked pulse series,with the averaged power of 92. 2 mW,output pulse duration of 6. 2 ps,and pulse repetition frequency of 26. 6 MHz,corresponding to the pulse energy of 3. 5 nJ,was obtained in the optimized filter position under a pump power of 320 mW. By the numerical simulation,the propagation dynamics of pulses in the three cases of spectral filter （SF） position in the cavity are obtained and analyzed. The optimal location of the SF is found,which is in agreement with our experimental result.