Improvements of high power diode laser line generators open up new application fields

摘要

Beam shaping improvements of line generators based on high power diode lasers lead to new application fields as hardening, annealing or cutting of various materials. Of special interest is the laser treatment of silicon. An overview of the wide variety of applications is presented with special emphasis of the relevance of unique laser beam parameters like power density and beam uniformity. Complementary to vision application and plastic processing, these new application markets become more and more important and can now be addressed by high power diode laser line generators. Herewith, a family of high power diode laser line generators is presented that covers this wide spectrum of application fields with very different requirements, including new applications as cutting of silicon or glass, as well as the beam shaping concepts behind it. A laser that generates a 5m long and 4mm wide homogeneous laser line is shown with peak intensities of 0.2W/cm~2 for inspection of railway catenaries as well as a laser that generates a homogeneous intensity distribution of 60mm × 2mm size with peak intensities of 225W/cm~2 for plastic processing. For the annealing of silicon surfaces, a laser was designed that generates an extraordinary uniform intensity distribution with residual inhomogeneities (contrast ratio) of less than 3% over a line length of 11mm and peak intensities of up to 75kW/cm~2. Ultimately, a laser line is shown with a peak intensity of 250kW/cm~2 used for cutting applications. Results of various application tests performed with the above mentioned lasers are discussed, particularly the surface treatment of silicon and the cutting of glass.