disk laser: Coupling of four disks in one resonator in accordance with concept of neutral gain modules, laser output power 3 kW.
Thermographic image of a thin disk, pumped with 300 W.
For the development of powerful laser sources with high beam quality, the activities are focused on concepts based on the thin disk laser. These diode pumped solid-state lasers combine power scalability with excellent brilliancy and high efficiency. The laser active medium consists of an extremely thin crystal disc (only a few hundred micrometres thick), which is cooled on the back surface. This enables extremely high pump power densities with minimised thermal lensing effects. The power scaling can be carried out for instance by enlarging the active surface at a constant pump power den-sity. Here, both the temperature in the disk and the necessary brilliance of the pump diodes remain constant.
Today, industrial thin disc lasers are available with up to 16 kW continuous output power. These lasers typically operate in multi mode with M² > 20. The Institute of Technical Physics focuses its work on the verification of the power scalability of thin disk lasers with virtually diffraction limited beam quality up to the highest power range.