Background The propagation of high-power lasers through the atmosphere is subject to thermal blooming effects, which arise from wavelength-dependent atmospheric absorption and subsequent refractive index perturbations. Supercontinuum lasers, characterized by broad spectral bandwidths, introduce additional complexity due to differential absorption and attenuation across their spectral components.

Purpose This study aims to develop a numerical simulation method for the thermal blooming effect during atmospheric propagation of supercontinuum lasers, with particular focus on accounting for the differential atmospheric absorption and attenuation across various wavelengths within the supercontinuum spectrum.

Methods Based on Maxwell’s wave equations for light propagation and the fluid dynamics equations for atmospheric thermal absorption, a numerical simulation model was established using a multi-layer phase screen Fourier transform method and a multi-wavelength incoherent superposition approach. A thermal blooming phase screen was constructed by integrating the spectral distribution of the supercontinuum laser source with principles of atmospheric radiative transfer to characterize the cumulative thermal effects from atmospheric absorption at each wavelength component. The reliability of the simulation model was verified by comparing its results with existing theoretical outcomes for single-wavelength laser atmospheric thermal blooming.

Results Using the proposed numerical simulation model, preliminary simulations were conducted on the atmospheric thermal blooming effects of supercontinuum lasers at different emission powers. Key parameters such as typical on-target intensity distribution, centroid offset, Strehl ratio, and energy distribution curves for atmospheric propagation were calculated. The results reveal the unique intensity distribution and certain beam characteristics of the supercontinuum laser.

Conclusions The numerical method proposed in this paper provides a foundational research tool for studying the thermal blooming effects in high-power supercontinuum laser atmospheric propagation.