研究了亚纳秒脉冲抽运光子晶体光纤产生高功率超连续谱的机理.采用掺镱锁模光纤激光器产生的脉宽570 ps光脉冲，抽运1.8 m光子晶体光纤，得到了平均功率为1.15 W、光谱覆盖范围为750 nm的超连续谱.通过实验和模拟结果的对比和分析，证实了亚纳秒脉冲抽运1.8 mPCF产生超连续谱时，调制不稳定性效应起了重要作用.在研究了不同抽运功率下输出的超连续谱变化后，发现随着抽运功率的提高，输出功率也更高且超连续谱覆盖波段也更宽，在瓦级输出功率下依然未达到饱和展宽状态，还有进一步提高功率和展宽光谱的空间.

To research the mechanism of high power supercontinuum generation by sub-nanosecond pulse pumping photonic crystal fiber (PCF),a 1.8 m PCF is pumped by 570 ps pulses from a Yb-doped mode-locked fiber laser,and it puts out SC (supercontinuum) with 1.15 W power and 750 nm spectral coverage.It is verified that when SC is generated by sub-nanosecond pulse pumping 1.8 m PCF,the modulation instability (MI) takes an important part in expanding spectrum via comparing and analyzing the experiment with simulation.After researching the change of SC under different pump power,it is found that the power of SC increases and the spectral coverage expands with the pump power.Under watt power output,it still does not reach saturated section,and be probable to get higher power and broader spectrum.