25 August 2015 Beam shaping concepts with aspheric surfaces
Author Affiliations +
Employing aspherical lenses to reduce aberrations to improve focusing qualities is a well-known concept. But the potpourri of aspheric surfaces offers way more possibilities, even the chance for flexible beam shaping setups. Since these are refractive optical elements the beam shaping is robust with respect to wavelength changes. Being able to generate ring shaped light distributions is interesting for various applications. Here the most uncommon aspheric surface – an axicon – is utilized. Axicons are glass cones, which convert the incoming light into Bessel beams. Those are characterized by their concentric ring structure and long depth of focus, which makes them very interesting for material processing. Above that, combining such an axicon with a focusing lens leads to a ring focus. Its size is not only determined by the choice of the axicon angle and the lens properties, but also through the diameter of the incoming beam. Thus, for optimal usage a flexible beam expander, which leaves the beam quality unaltered is mandatory. The remarkable properties of these beam shaping set-ups are shown in theory and experimentally. Furthermore, a configuration consisting of two axicons and interchangeable focusing lenses is presented. For one thing, this set-up allows for tuning of the working distance in any required way for optimal material processing. For another thing, the induced chromatic focal shift of the focusing lens that occurs by a change of wavelength can be compensated for by adapting the distance of the axicons and leaving the working distance unchanged.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
U. Fuchs, U. Fuchs, D. Braun, D. Braun, S. Wickenhagen, S. Wickenhagen, } "Beam shaping concepts with aspheric surfaces", Proc. SPIE 9581, Laser Beam Shaping XVI, 95810L (25 August 2015); doi: 10.1117/12.2186524; https://doi.org/10.1117/12.2186524


Flexible and robust beam shaping concepts with aspheres
Proceedings of SPIE (March 05 2014)
Gauss to top-hat beam shaping with aspheres
Proceedings of SPIE (March 17 2016)
Development of an adaptive laser beam shaper
Proceedings of SPIE (February 15 2018)
Telephoto axicon
Proceedings of SPIE (October 14 2005)

Back to Top