For high-speed, high-power laser welding, a clean weld may be achieved when using a special illumination profile consisting of a spot and concentric ring. The optimal power ratio between the spot and the ring differs for different welding process parameters and system designs, so an adjustable ring to spot ratio enables the user to find the optimal ratio for each process.
For this application, LASER COMPONENTS offers the Flexishaper™ beam shaping module from partners HOLO/OR. This module uses two identical diffractive optical elements placed on the same optical axis which, when rotated against one another can shape the beam propagated through them from 100% of the power in the central spot to ~80% of the power at the surrounding ring with almost no energy at the centre, with a continuous full range control of the power ratio in between these states.
The Flexishaper™ pair can be used with both single mode and multi-mode lasers, and can be adapted for large beams typically used with multi-kW lasers.
For further information Diffractive Optical Elements (lasercomponents.com)