光纤激光器中锁模孤子序列的长周期脉动

Long Period Pulsation of Mode-locked Soliton Trains in Fiber Laser

实验观察到非线性偏振旋转锁模光纤激光器中锁模孤子及孤子簇的长周期脉动现象。单孤子与孤子簇的脉动周期达103和102次脉冲周期量级。脉动周期及脉动包络形状与抽运功率及腔内偏振设置有关。孤子脉冲的长周期脉动现象归因于不严格的1阶偏振态设置。不严格的1阶偏振态设置使得偏振相关隔离器对每次腔内循环的锁模孤子脉冲进行了微弱的周期偏振滤波。积累的偏振滤波损耗导致了锁模脉冲序列出现长周期脉动。

Observed is the long period pulsation of the mode-locked solitons and soliton bunches in nonlinear polarization rotation fiber laser. The period of the single soliton and the soliton bunching can reach the order of 103 and 102 cavity round trips,respectively. The pulsation period and the pulsation profile are related with the pumping power and the polarization bias. The long-period pulsation owes to the imprecision of the first order polarization state bias,which leads to the slight polarization modulated filtering of the polarization-dependent isolator on the mode-locked solitons in each round trip. The accumulated modulation loss arouses the long-period pulsation of the mode-locked pulse trains.