利用非线性偏振旋转锁模技术产生0.7nJ,1.5ps光脉冲

Generation of 1.5ps pulses with 0.7nJ of energy based on polarization additive pulse mode-locking

为了研究锁模光纤激光器以增益平坦型掺铒光纤放大器作为增益介质对输出特性的影响,采用增益平坦型掺铒光纤放大器结合光纤偏振控制器、偏振相关光隔离器组成锁模光纤激光器,基于非线性偏振旋转锁模技术,实现稳定、自起振锁模运转,得到了中心波长1560nm、重复频率6.495MHz、单脉冲能量0.7nJ、脉宽1.5ps的超短光脉冲。同时实验观察到峰值波长为1557nm和1570nm的双峰值波长锁模脉冲的产生。结果表明,采用增益平坦型掺铒光纤放大器替代普通掺铒光纤组成锁模光纤激光器,可获得较高单脉冲能量的超短光脉冲,锁模脉冲的输出光谱可能出现双峰结构,从而可为超短脉冲光纤激光器设计及实用化提供参考。

The dynamics characteristics of a mode-locking laser using a gain-flattened erbium doped fiber amplifier are reported. Based on polarization additive pulse mode locking technique, a serf-starting mode-locking of the fiber laser was demonstrated with a gain-flattened erbium doped fiber amplifier, fiber polarization controllers and a polarization dependent isolator. The stable optical pulses train at 1560nm center wavelength and 6. 495MHz repetition rate was generated, with 1.5ps pulse width and 0.7nJ pulse energy. Mode locked pulses with dual peak-wavelengths at 1557nm and 1570nm were also observed. The results of the experiment indicate that higher energy of the pulses can be generated by the fiber laser with a gain-switched erbium doped fiber amplifier than that with a general erbium doped fiber. The mode-locked pulse spectrum of the fiber laser with a gain-flattened erbium doped fiber amplifier could show dual peak structure. It＇s valuable to the design and practicability of the ultra-short fiber lasers.