由于外差或频差效应，能够得到多普勒频率。
The Doppler frequency can be obtained as a heterodyne or beat effect.
高阶差分加上合适的边界条件能较好地解决网格频散和边界效应问题。
When a suitable boundary condition is given, this method can solve the problems of the numerical dispersion and boundary effectiveness.
通过理论分析和数值模拟研究了在双脉冲泵浦情况下的级联和频与差频的二阶非线性效应，探讨了走离效应对波长转换的影响。
Through theoretical analysis and numerical simulations, the walk-off effect between sum-frequency pulse and pump pulse caused by Group Velocity Mismatch (GVM) was discussed.
通过理论分析和数值模拟研究了在双脉冲泵浦情况下的级联和频与差频的二阶非线性效应，探讨了走离效应对波长转换的影响。
Through theoretical analysis and numerical simulations, the walk-off effect between sum-frequency pulse and pump pulse caused by Group Velocity Mismatch (GVM) was discussed.
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