Ultrafast laser sources have already demonstrated their advantages in several different applications due to their exceptional temporal characteristics. By tailoring the laser beam in propagation direction and in the plane of the workpiece surface new applications are accessible. In addition current applications benefit as well due to an increase in efficiency and flexibility. We demonstrate how the new technology of ultrafast laser polishing will benefit from a homogenous intensity distribution with a top-hat beam profile. Another example is materials processing with elongated beam shapes and small spot sizes by utilizing an axicon generated Bessel beam. Bessel shaped beams are especially used to generate in-volume-modifications in transparent materials, like glasses or sapphire, for cutting applications. A common approach to increase throughput in ultrafast laser applications by one order of magnitude is the use of diffractive optical elements (DOE) for beam splitting. Special challenges here are to compensate chromatic aberrations or distortions in combination with scanning techniques.
Besides the generation of the mentioned intensity distributions with static optical elements, the beam shaping approach with spatial light modulators (SLM) provides a flexible tool for customized intensity distributions in all lateral directions. The advantages of this flexibility are applied to compensate aberrations (e.g. in-volume-modification) and to improve productivity (flexible multi beams with finishing to retain process quality).
Keywords
- Aberration
- Beam Shaping
- Bessel
- Doe
- Slm