Thin disk laser: power scaling to the kW regime in fundamental mode operation

Abstract

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 M 2 = 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.

Optical model and optimal output coupler for a continuous wave Yb:YAG thin-disk laser with multiple-disk configuration

“…On the other hand, when the thin-disk laser is operating at an optimal value of output coupler reflectivity, optical-to-optical efficiency is almost independent of the number of thin disks. The simulation results from theoretical analysis and numerical calculation agree well with experimental data from the relational literature [16,17]. Figure 9 shows laser output intensity as a function of output coupler reflectivity for the various reflectivity of connection mirrors.…”

Thermal effects in high-power Nd:YAG disk-type solid state laser

“…As reported in [6], although the disk-type laser has the advantageous features mentioned above, there is still serious thermal distortion, which has a serious influence on laser output power and beam quality. On the one hand, uniform pump power deposition in the transverse cross section is hard to be achieved in practice.…”

Analytical model of optical path difference in an end-pumped Yb:YAG thin-disk laser with nonuniform pumping light

“…Although these reports show good experimental results, thermal effects and aberration are still the main factors limiting the average power and scalability of thin-disk lasers, especially for high pump power and fundamental-transversal-mode operation. In order to further improve the brightness of thindisk lasers, intensive research is being carried out on thermal-optical aberrations, thermal lensing, and compensation techniques [4][5][6].…”