New approach for high-power diode laser modules with homogenized intensity distribution

摘要

In the last few years high-power diode laser modules with homogenized intensity distribution have found a growing number of applications, like annealing, hardening and surface illumination. The standard beam shaping concepts in such modules are using an optical waveguide or microoptical lens arrays for homogenization. For the generation of long lines with high aspect ratio these concepts have some significant drawbacks, especially if the line is composed of several sub-modules with shorter line segments. The homogeneity in the transition zone of these segments is always difficult to handle.rnIn this paper we report on a new approach for homogenization of high-power diode laser modules by using linearly arranged fiber bundles to generate homogeneous lines. The main advantage of this concept is that scaling of line length is easily achieved by increasing the number of linearly arranged fibers. We present a detailed characterization of such a modular diode laser system with 3 kW output power and homogenization by means of a fiber bundle. The dimension of the homogenized line is 150 mm x 2.5 mm.rnIn addition we present a number of different diode laser modules with homogenization by means of classical approaches, like microoptical cylindrical lens arrays. The output power of these modules ranges from 50 W to 11 kW with line dimensions from 3 mm x 50 urn up to two dimensional homogenized areas of 55 x 20 mm2.