色散平坦渐减光纤中超连续谱的产生

对双正交偏振光脉冲在色散平坦渐减光纤中传输时超连续谱的产生进行了计算和分析。结果表明，由于交叉相位调制效应的作用，双光脉冲可以产生比单光脉冲明显展宽且更为平坦的超连续谱。对于双基孤子脉冲，可以得到-20dB谱宽达388nm的平坦宽带超连续谱，比单基孤子脉冲产生的超连续谱谱宽增加72nm，交叉相位调制效应对超连续谱的产生起到增强的效果。当输入脉冲的抽运功率较低时，交叉相位调制效应对超连续谱的产生的增强效果更为显著，它极大地提高了超连续谱的产生的效率。数值计算的结果还表明，与其他高阶非线性效应相比，拉曼自频率移效应对超连续谱产生的影响更为明显。

Generation of Supercontinuum Spectrum in a Dispersion-Flattened and Decreasing Fiber due to Cross-Phase Modulation

Supercontinuum spectrum generation in a dispersion-flattened and decreasing fiber with two orthogonally polarized pulses was simulated and calculated. The research results indicates that the supercontinuum spectrum generated by two orthogonally polarized pulses is wider and flatter than that generated by single polarized pulse due to cross-phase modulation. A flat and broad bandwidth of 388 nm at -20 dB for supercontinuum spectrum of two fundamental soliton pulses is generated, and the bandwidth is 72 nm wider than that generated by single fundamental soliton pulse. The cross-phase modulation effect can enhance the supercontinuum spectrum generation. When the pump power of the input pulse is lower, the enhancement on supercontinuum spectrum generation due to cross-phase modulation effect is more significant. The cross-phase modulation effect increases the supercontinuum spectrum generation efficiency greatly. Numerical analysis also shows that the Raman self-frequency shift effect has more significant effect on supercontinuum spectrum generation than other higher-order nonlinear effects.