中文摘要：

利用倍频光与泵浦光脉冲之间的走离效应，通过在周期性极化的LiNbO3波导中间增加两段未被极化的波导，1．55μm波段的泵浦脉冲在极化的波导部分产生0．77μm波段的倍频光，在未被极化的部分不产生倍频光，形成了三个被间隔开来的倍频子脉冲．通过差频将三个倍频子脉冲还原成1．55μm波段的三个差频脉冲，实现了用一个泵浦脉冲产生三个转换脉冲．用数值模拟计算展示脉冲的产生及其演化过程，并讨论了用LiNbO3波导参量控制脉冲特征参量的方法．

英文摘要：

Using the walk-off effect between pump pulse and harmonic pulse, triple-pulses is produced by second-harmonic generation in periodically-poled lithium-niobate-waveguide in which two pieces of nonpoled waveguide is inserted. Three 0.77 μm-band harmonic pulses are generated by 1.55 μm-band pumppulse in poled segments, but they are separated in non-poled segments, Then three harmonic pulses are converted to three 1.55 μm-band converted pulses by difference-frequency generation. The configuration of triple-pulses produced by one pump pulse is implemented, the generation and the waveform-evolution of triple-pulses is exhibited by numerical simulations, and the method of controlling pulse＇ s characteristic parameter with waveguide size is analyzed as well.