【摘要】 从超短脉冲光束的傍轴传输方程出发,得出了描述任意脉冲形式驱动的等衍射超短脉冲厄米高斯光束在自由空间中的解析表达式.并通过例子研究了超短脉冲厄米高斯光束的传输性质.结果表明:在传输过程中,由于群速度的空间分布不均匀性,会导致超短脉冲光束的脉冲时间延迟,并进而导致了在脉冲不同位置处光束横向分布严重偏离了厄米高斯函数.另外,在传输过程中,发现不同阶数的脉冲厄米高斯光束会发生不同次数的极化反转.并用脉冲光束的群-相速度差对这一现象进行了解释.更多还原

【Abstract】 A family of solutions called iso-diffraction ultra-short pulsed Hermite Gaussian beams (UPHGB) are obtained based on the paraxial propagation equation. The propagation of UPHGB is investigated in detail. The examples shows that:the nonuniformlly distributed group velocity causes the time delay at the beam periphery,which in turn induces the deviation of the transverse distribution from the Hermite Gaussian function. In propagation,the number of pulse polarity inverions varies with the order of the UPHGB. And this phenomenon originates in the difference between the group velocity and the phase velocity in UPHGB.更多还原