Beam reformatting of CO₂ array lasers

For CO₂ lasers, high power array sources are available using RF discharge excitation of waveguide laser channels in both linear and 2-D array format. The high optical beam quality of the laser output from each individual waveguide channel of the array enables the manipulation of the individual beams in the near-field to improve the composite beam quality and/or reformat the beam shape to one which is optimized for a particular material processing application. A Clarkson-Hanna optical arrangement can be employed to increase the fill factor and brightness of the 2-D array. By adding simple astigmatic reflective optics, rectangles of variable aspect ratio can be generated at the work surface. In comparison with alternative methods of beam reformatting, this method has the advantage of low cost, simplicity and low insertion loss, while providing access to a range of rectangular beam shapes for surface processing applications.