正常色散区泵浦微结构光纤产生超连续谱研究

用实验和数值模拟两种方法研究在正常色散区内用飞秒脉冲泵浦微结构光纤产生超连续谱的机理．研究发现，在初始阶段，自相位调制对光谱展宽起主要作用，连续谱平坦；当光谱展宽进入反常色散区后，拉曼效应和反常色散的作用使光谱分裂．泵浦波长在正常色散区内离零色散点越远，得到的超连续谱宽度越小，但其在正常色散区的部分光谱却更平坦．

Research on the supercontinuum generation in a microstructured fiber pumped at the normal dispersion region

The mechanism of supercontinuum generation was experimentally and theoretically studied in a microstructured fiber when pumped at its normal dispersion region by using femtosecond laser pulses. Our work indicates that the self-phase modulation (SPM) effect is the fundamental mechanism at the initial stage, resulting in a flat continuum. However, when extended into the abnormal dispersion region, the continuum would be splitted due to the Raman effects and the abnormal dispersion. Moreover our experiment obtains that when the pump wavelength in the normal dispersion region lies farther from the zero-dispersion wavelength, the generated supercontinuum would be narrower, while the part of spectrum in the normal dispersion region would be flatter.