Beam shaping unit for microprocessing on the base of refractive beam shapers

Abstract

Spatial beam shaping is very important in various laser microprocessing techniques like scribing, PCB drilling and others where scanning over working field with using galvo mirror scanners is used. Therefore, combining of beam shaping optics, converting Gaussian to flat-top (uniform) laser beam irradiance profile, with scanning optical heads is an insistent technical task. As a proved solution for beam shaping it is suggested to apply field mapping refractive beam shapers piShaper with important features: low output divergence, high transmittance, extended depth of field, operation with TEM00 and multimode lasers. De-magnifying of flat-top laser beam can be realized by imaging optical system composed from F-Θ lens of scanning head and additional collimator. Difficulty of this approach is implementation of compact design of the collimating part. Solution is suggested in form of specially designed Beam Shaping Unit (BSU) installed between a laser and a scanner and providing: irradiance profile conversion from Gaussian to flat-top, compact collimator design, functions of adjustment and adaptation to real lasers and scanners. There will be considered design features of refractive beam shapers and BSU and optical layouts to generate flat-top laser spots. Examples of real implementations and results of material processing will be presented as well.Spatial beam shaping is very important in various laser microprocessing techniques like scribing, PCB drilling and others where scanning over working field with using galvo mirror scanners is used. Therefore, combining of beam shaping optics, converting Gaussian to flat-top (uniform) laser beam irradiance profile, with scanning optical heads is an insistent technical task. As a proved solution for beam shaping it is suggested to apply field mapping refractive beam shapers piShaper with important features: low output divergence, high transmittance, extended depth of field, operation with TEM00 and multimode lasers. De-magnifying of flat-top laser beam can be realized by imaging optical system composed from F-Θ lens of scanning head and additional collimator. Difficulty of this approach is implementation of compact design of the collimating part. Solution is suggested in form of specially designed Beam Shaping Unit (BSU) installed between a laser and a scanner and providing: irradiance profile conversion fr...