Beam shaping technology has emerged as a key approach for improving weld quality, process stability, and efficiency in laser welding. Conventional Gaussian beams encounter significant limitations in modern welding applications, particularly when processing highly reflective materials and suppressing typical welding defects. This review systematically summarizes recent progress in beam shaping techniques for laser welding, covering various beam profiles, including Gaussian, elliptical, flat-top, and ring-shaped beams. Special emphasis is placed on how tailored energy distributions influence molten pool dynamics, keyhole stability, and defect formation mechanisms. By modulating the spatial intensity distribution, beam shaping enables more precise control of heat input, thereby reducing porosity, spatter, and molten pool instabilities while expanding the available process window. Furthermore, recent advances in dynamic beam shaping, achieved through diffractive optical elements (DOEs), deformable mirrors (DMs), and related optical components, are discussed in detail. These approaches allow real-time adaptation of beam profiles to accommodate different materials and welding conditions. With the rapid development of multi-beam systems and high-power laser sources, dynamic beam shaping has demonstrated significant potential in enhancing process robustness and welding consistency, particularly for high-precision manufacturing and complex material joining. This review provides a comprehensive framework linking beam shaping strategies with welding physics, offering both theoretical insights and practical guidance for future research and industrial applications.
Chen et al. (Sat,) studied this question.