光纤激光器中基于偏振控制器的脉宽可调平顶光脉冲生成技术

Flat-top Pulse Generation with Pulsewidth Tunable Based on Polarization Controller in Fiber Laser

提出了主动锁模联合非线性偏振旋转光纤激光器中基于偏振控制器的脉宽可调平顶光脉冲生成技术．光纤激光器由主动锁模部分和一根掺Bi的高非线性光纤联合两个偏振控制器及光纤检偏器构成的非线性偏振旋转结构组成．分析了该实验装置在不同状态下的工作机制，通过调节激光器中的两个偏振控制器，实验获得了10GHz的脉宽可调平顶光脉冲，脉宽调节范围在12～19ps之间，调节激光腔中的宽带滤波器，可在不同波长处获得平顶光脉冲．实验表明：输出的平顶光脉冲性能稳定，边模抑制比为65dB，定时抖动145fs．

A pulsewidth tunable 10 GHz flat-top pulse train was generated based on the combined action of active mode locking and nonlinear-polarization-rotation pulse shaping. The laser cavity consisted of two parts., one was a commonly used active-mode-locking fiber laser; the other was for NPR based pulse shaping, which was composed of two PCs between which a high nonlinear fiber was inserted, and an in- line polarizer, was inserted into the cavity to control the pulse shape. The setup has previously been used for pulse compression, while the generation of FTP was proposed based on it. As a result, 10 GHz flat- top pulse with pulsewith tunable from 12~19 ps by tuning polarization controllers was generated, and flat-top pulse were obtained at different wavelength by tuning band pass filter. The output pulse shows good stability, with the measured side mode supress ratio of 65 dB and the timing jitter of 145 fs.