Asymmetric steady thermal blooming

The thermal blooming of a thulium laser near 2 µm in an enclosed chamber is considered, as in Cook <i>et al.</i> [Opt. Laser Technol.146, 107568 (2022)OLTCAS0030-399210.1016/j.optlastec.2021.107568]. The problem is modeled using the paraxial equation for the laser and the Navier-Stokes equations with a Boussinesq approximation for buoyancy-driven effects. These equations are solved numerically in the steady experimental configuration. The numerical procedure uses radial basis functions (RBFs) to approximate spatial derivatives and the hybrid Padé-Newton approach by Lane and Akers [Stud. Appl. Math.10, e12740 (2024)SAPMB60022-252610.1111/sapm.12740] to solve the resulting system of nonlinear equations. Numerical simulations are compared to experimental results. The simulations explain the asymmetry of laser spots as the result of the influence of the tank's boundary on the global convective flow.