Akers Benjamin F, Fiorino Steven T, Reeger Jonah A
Appl Opt. 2023 Aug 10;62(23):G77-G84. doi: 10.1364/AO.487903.
The propagation of a high energy laser through a nearly stagnant absorbing medium is studied. The absorption values and time scale of the problem are such that the laser induces convective heat currents transverse to the beam. These currents couple to the laser via the refractive index, causing time dependent thermal blooming. A numerical method is developed and applied to the model in [J. Electromagn. Waves Appl.33, 96 (2019)JEWAE50920-507110.1080/09205071.2018.1528183], using radial basis functions for spatial differencing, which allows for irregular point spacings and a wide class of geometries. Both the beam and laser-induced fluid dynamics are numerically simulated. These simulations are compared to a historical experiment of a 300 W laser in a smoke-filled chamber with good agreement; both cases include a crescent shaped spot at the target.
研究了高能激光在几乎静止的吸收介质中的传播。该问题的吸收值和时间尺度使得激光诱导出垂直于光束的对流热流。这些热流通过折射率与激光耦合，导致随时间变化的热晕。开发了一种数值方法并将其应用于[《电磁波应用杂志》33, 96 (2019)JEWAE50920 - 507110.1080/09205071.2018.1528183]中的模型，该方法使用径向基函数进行空间差分，允许不规则的点间距和广泛的几何形状。对光束和激光诱导的流体动力学进行了数值模拟。将这些模拟结果与在充满烟雾的腔室中进行的300瓦激光的历史实验进行了比较，结果吻合良好；两种情况在目标处都包括一个月牙形光斑。
