Liu Dongfeng, Zhu Xiaojun, Wang Chinhua, Yu Jianjun, Hu Danfeng
Institute of Modern Optical Technologies, Soochow University, Suzhou, Jiangsu, China.
Appl Opt. 2011 Feb 1;50(4):484-91. doi: 10.1364/AO.50.000484.
We report an all-normal-dispersion, low-repetition-rate, high-energy, twin-pulse, passively mode locked ytterbium-doped fiber laser. The mode-locking mechanism of the laser is based on nonlinear polarization evolution and strong pulse shaping with a cascade long-period fiber grating bandpass filtering in a highly chirped pulse. The laser generates a highly stable twin-pulse group with 248 ps and 296 ps duration simultaneously and maximum pulse energy of 26.8 nJ-each pulse at a 2.5445 MHz repetition rate. Energy quantization is observed, which demonstrates the nonparabolic nature of these pulses. The laser can also work in third-harmonic mode locking with 17.8 nJ energy (at a repetition rate of 7.65 MHz and pulse width of 780 ps).
我们报道了一种全正色散、低重复频率、高能量、双脉冲、被动锁模掺镱光纤激光器。该激光器的锁模机制基于非线性偏振演化以及在高啁啾脉冲中通过级联长周期光纤光栅带通滤波进行的强脉冲整形。该激光器同时产生持续时间分别为248 ps和296 ps的高度稳定双脉冲组，在2.5445 MHz重复频率下每个脉冲的最大脉冲能量为26.8 nJ。观察到了能量量子化，这证明了这些脉冲的非抛物线性质。该激光器还可以在三次谐波锁模下工作，能量为17.8 nJ（重复频率为7.65 MHz，脉冲宽度为780 ps）。
