Near fundamental mode 11 kW Yb:YAG thin-disk laser

Abstract

We report on a Yb:YAG thin-disk laser with 1.1 kW output power and beam quality factor M²<1.4 using a simple stable resonator comprising just a single cavity mirror and a single thin disk, without the use of any aspherical elements or any adaptive optics. An optical-to-optical efficiency of 40% was obtained. The cavity was designed to give good beam quality and low misalignment sensitivity to maintain stable and robust laser operation throughout the changes in the thin-disk curvature. To the best of the authors' knowledge, this is the first time an output power beyond 1 kW has been achieved from a single thin-disk laser in near fundamental mode operation (M²<1.4).

Alexandrite: an attractive thin-disk laser material alternative to Yb:YAG?

“…Comparing the simulation results with the literature, we see that using a 10%-doped 110-140 μm thick Yb:YAG TD laser material, cw slope efficiencies of 82% has been achieved from a Yb:YAG laser with multi transverse mode laser output by pumping at the zero-phonon line (1 kW output power, 4.5% output coupler, 1.5 kW pump power, a pump spot diameter of 5.6 mm) [40]. Usually, laser efficiencies decrease to around 50% level, for cavities that support almost transform limited beam profiles (corresponds to a lower MMF in our simulations) [41]. Before ending this section, we need to mention that the induced thermal effects might distort the beam quality and lower laser performance at TD temperatures above ∼150-200 °C.…”

Latest Advances in High Brightness Disk Lasers

“…This changes however when beam quality is close to fundamental mode. Until mid 2013, the highest reported TEM 00 power for a single disk resonator was 1 kW [2]. Today's disk technology offers significant advantages regarding thermal management and aberration losses, enabling much higher power.…”

Modelling of natural convection in thin-disk lasers

“…In fact, the knowledge of the influence of these parameters on the laser operation is of crucial importance for the design of advanced high-power fundamental-mode thin-disk oscillators [4] and amplifier systems [6,7]. Although a variety of different methods exists to estimate and compensate for thermally induced aberrations [4,[8][9][10][11][12], a complete elimination of aberrations introduced due to natural convection is only possible by operating the whole laser in vacuum [13], which, however, leads to an increased amount of complexity. If this effort is to be avoided, the influence of the convection needs to be considered in detail to be able to optimize the countermeasures.…”