205 W TEM₀₀-mode-stacked Nd:YAG rotary disk laser with air cooling

We have demonstrated an efficient, high-power continuous-wave Nd:YAG laser utilizing a stacked and rotary-disk configuration for the gain medium. The disks were air-cooled at room temperature. By employing a diode laser pump power of 347 W in a fiber-coupled end-pumped setup, we achieved an output power of 205 W in the fundamental transverse mode from the simplest resonator cavity. The beam quality factors (M²) in the orthogonal directions were measured at 1.143 and 1.169, respectively. The optical slope efficiencies were approximately 68%. Additionally, the root mean square (RMS) of the laser's instability, measured continuously over a period of 6 hours, was found to be 0.276%.