Elke Schmid

Thin-disk laser - Power scaling to the kW regime in fundamental mode operation

A significant reduction of the influence of the thermal lens in thin-disk lasers in high power laser operation mode could be achieved, using dynamically stable resonators. For designing the resonator, investigations of thermally induced phase distortions of thin-disks as well as numerical simulations of the field distribution in the resonator were performed. This characterization was combined with thermo-mechanical computations. On the basis of these studies, about 500 W output power with an averaged M2 = 1.55 could be demonstrated, using one disk. Almost 1 kW output power with good beam quality could be extracted, using two disks. For the purpose of further power scaling in nearly fundamental mode operation, experiments using more than two disks are in preparation.

Thin-Disk Lasers with Dynamically Stable Resonators

A significant reduction of the influence of the thermal lens for high power laser operation could be achieved in a thin-disk laser by systematic characterization of the thin-disk laser medium and the utilization of a dynamically stable resonator. Furthermore, the power scalability of the thin-disk laser concept could be demonstrated with two disks in one resonator and with large pump spot radii, realizing an output power of approximately 1 kW with nearly diffraction limited beam quality.

Power scaling of high power thin-disk lasers with high beam quality

Since the invention of the thin-disk laser 16 years ago [1], high output power and high optical efficiency made this type of solid-state lasers a common tool for industrial applications like cutting and welding. Nowadays, thin-disk lasers for material processing with an output power up to 16 kW are commercially available. The highest published output power of an Yb:YAG single-disk laser is 5.3 kW in multi-mode operation [2].