3D Spatiotemporal Evolution of the Mode Field in Multimode Lasers

Abstract Multimode lasers hold broad potential applications in industrial processing and biomedical imaging. The developing a comprehensive 3D characterization method and the achievement of full‐dimensional light field analysis are essential for advancements this field. In this study, a 3D spatiotemporal mode construction model for multimode lasers is proposed and the corresponding spatiotemporal influence law is analyzed. The results indicate that the 3D light field exhibits distinct spatiotemporal scattered particle characteristics. The size of the scattered particle volumes is jointly determined by the transverse and longitudinal mode numbers. The longitudinal mode numbers govern the temporal coherence length, while the transverse mode numbers determine the spatial distribution. These findings facilitate the optimization of laser design, enhance spatiotemporal control in optical imaging, and provide a crucial theoretical foundation for a deeper understanding of multimode evolution mechanisms during nonlinear conversion process.