基于非线性偏振旋转锁模的高功率光子晶体光纤飞秒激光振荡器

A high power photonic crystal fiber laser oscillator based on nonlinear polarization rotation mode-locking*

为了探索大模场面积光子晶体光纤锁模激光器在全正色散锁模域内的耗散孤子锁模机理,以获得更大的单脉冲能量和更高的峰值功率,本文搭建了以掺镱大模场面积光子晶体光纤作为增益介质的耗散孤子锁模激光器.激光器使用环形腔结构,利用非线性偏振旋转以及滤光片提供的耗散作用实现了稳定的锁模运转.实验中,从激光器振荡级直接获得了平均功率10 W,重复频率49.09 MHz(对应202 nJ的单脉冲能量),脉冲宽度为1.03 ps的稳定锁模脉冲输出,经过腔外色散补偿得到的脉冲宽度为95.5 fs.

A high power femtosecond fiber laser based on a Yb-doped large mode area photonic crystal fiber operating in an all-normal dispersion regime is experimentally demonstrated.A ring laser cavity is used without any elements for dispersion compensation. Stable mode-locking is achieved through nonlinear polarization rotation and the dissipative function of a filter.The laser directly outputs 1.03 ps chirped pulses at a 49.09 MHz repetition rate for an average power of 10 W,corresponding to a pulse energy of 202 nJ. The pulses are compressed to 95.5 fs with a grating pair outside the cavity.