Feng S, Winful H G
EECS Department, University of Michigan, 1301 Beal Avenue, Ann Arbor, MI 48109-2122, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2001 Apr;63(4 Pt 2):046602. doi: 10.1103/PhysRevE.63.046602. Epub 2001 Mar 20.
We present a family of space-time nonseparable analytic solutions describing spatiotemporal dynamics of isodiffracting single-cycle and few-cycle pulses with Hermite-Gaussian and Laguerre-Gaussian transverse profiles. These solutions are space-time localized wave packets propagating in free space. The transverse field profile acts as a spatially dependent filter, modifying the pulse spectrum and removing certain frequencies. The consequences of those effects in the time domain are the distortions of pulse envelope and temporal wave form and the creation of "dark pulses" at certain transverse positions. In addition, due to the space-time coupling, the instantaneous transverse field pattern changes inside the pulse, as well as with propagation distance. These higher-order mode solutions can be used to analyze reflected or scattered terahertz pulses, and to understand the wave-form distortions of terahertz signals in applications. They are also capable of modeling pulsed fields of phase locking of both transverse and longitudinal modes in total mode-locked lasers.
我们提出了一族时空不可分离的解析解，用于描述具有厄米-高斯和拉盖尔-高斯横向分布的等衍射单周期和少周期脉冲的时空动力学。这些解是在自由空间中传播的时空局域化波包。横向场分布起到空间相关滤波器的作用，改变脉冲频谱并去除某些频率。这些效应在时域中的结果是脉冲包络和时间波形的畸变，以及在某些横向位置产生“暗脉冲”。此外，由于时空耦合，脉冲内部以及随传播距离，瞬时横向场模式都会发生变化。这些高阶模解可用于分析反射或散射的太赫兹脉冲，并理解太赫兹信号在应用中的波形畸变。它们还能够对全锁模激光器中横向和纵向模式的锁相脉冲场进行建模。
