通过数值模拟和实验研究了一种基于大模场面积光子晶体光纤的高功率全正色散自相似锁模激光器。激光器采用长为1.9 m 的掺镱双包层大模场面积光子晶体光纤作为增益介质，腔内没有引入色散图，整个激光器工作在全正色散域。激光器采用环形腔结构，利用非线性偏振旋转锁模和一个窄带高斯滤波器实现了稳定的自相似锁模运转。实验最终获得了直接输出平均功率为5 W，重复频率为72 MHz，单脉冲能量超过69 nJ，脉冲宽度为1.699 ps的自相似锁模脉冲输出，经过腔外1200 line/mm 的透射光栅对压缩后脉宽为84 fs。激光器可以实现自启动锁模，光束质量因子M²为1.41。

A high power self-similar fiber laser based on the Yb-doped large mode area photonic crystal fiber (LMAPCF) is studied by simulation and experiment. The laser is operated in an all-normal-dispersion region. To obtain higher power, the laser is performed by Yb-doped LMA-PCF without dispersion map with length of 1.9 m, which operates in the all normal dispersion. A ring cavity is employed and the stable mode-locking is achieved through nonlinear polarization rotation with a grating filter. The laser directly outputs the self-similar pulses with average power of 5 W at repetition rate of 72 MHz with pulse duration of 1.699 ps, corresponding to pulse energy of 69 nJ. The dechirped pulse is 84 fs which is compressed by a pair of 1200 line/mm transmission gratings. The laser shows good self-starting property with the beam quality factor M² of 1.41.