Laser beam shaping is an important tool for laser welding applications, particularly in battery welding where many combinations of materials, requirements and conditions can be present for production of a single unit. The ability to change intensity profile “on-the-fly”, without equipment changes, widens the processing window available to a single welding tool. Here we present a straightforward method for variable beam shaping, using freeform refractive optical elements in combination with conventional optical elements and systems.





PowerPhotonic’s manufacturing process is truly freeform, with no restrictions on rotational, translational or mirror symmetry. With this freedom, beam shaping elements can be designed to produce different output intensity profiles depending on the variation of another system parameter, such as input beam size, optic rotation or alignment. This allows optical power to be moved between different parts of an output profile with simple mechanical motion in the optical train. For example, translation of a single optic can result in adjustment of power between a central spot and a surrounding annulus.





In addition, freeform surfaces allow a wide variety of output profiles to be considered in the design, beyond the conventional Gaussians, flat-tops and rings. The flexibility in target intensity profiles combined with in-situ adjustability gives significant additional degrees of freedom for laser welding applications.