Laser beam shaping arrangement

Abstract

Apparatus for shaping a laser beam having a substantially ring-shaped cross-section in order to provide even heat distribution at a work station and to adjust the operational size of the beam at said station, comprising a cylindrical reflector positioned to receive and reflect the laser beam and direct the laser beam toward a work station with the beam laterally converged so as to provide a more concentrated even energy distribution at the work station. In a preferred form, the mirror is positioned to be at a focal distance from the work station and has adjusting means for adjusting the mirror to accommodate variations in focal length caused by different work pieces and to allow operation slightly away from focal length, if desired. The preferred form also comprises a second cylindrical reflector adjustably positioned to converge the laser at right angles to the first direction of convergence whereby the length of image of the laser on the work piece may also be adjusted. The cylindrical cross-sections should be conic sections and preferably are circular with the degree of curvature being rather small so as to have rather long focal lengths. In an alternate form, means are also provided to vibrate the beam whereby the image may be caused to oscillate at the work station and to cover a larger fixed area of operation.