Development and application of new high-power laser beam sources
The actual market volume of high-power lasers for manufacturing is dominated by diffusion cooled CO2 laser systems at the multi-kW range and lamp pumped Nd:YAG laser systems at the kW range. Substituting the lamps by diodes the Nd:YAG laser in rod design entered the market as diode pumped solid state laser of the first generation. With output powers up to 6 kW the diode pumped rod is used in industries for precision cutting and welding. Introducing advanced resonator designs the diode pumped solid state lasers of the second generation are on the way to become serious competitors. Tailoring the laser performance means to balance the fundamental phenomena involved in the laser action and especially to take full advantage of the diode laser as excitation source for the laser crystal. The mechanisms of excitation, amplification, and saturation in the crystal depending on spectral and spatial matching of the diode pump volume with the volume of the desired laser mode influence efficiency and beam quality. The new concepts for diode pumped solid state lasers will be compared by their abilities and efficiency to generate tailored energy density (wavelength, pulse energy, repetition rate, pulse duration, and beam quality) suitable for the requirements of the materials and the processes. Disc and slab laser systems already demonstrated the improved performance enabling new applications and as new high-power laser beam sources they mark the entrance to "The Bright Future of Laser Technology".