High-efficiency multi-kilowatt Er3+:YAG solid-state heat-capacity laser

First results on a diode-pumped multikilowatt-class Er(3+):YAG solid-state heat-capacity laser (SSHCL) are reported. The laser achieves an output power of 4650 W and output energies in excess of 440 J. A moderate crystal temperature increase due to crystal heating of 56.7 K/s is measured at 11.3 kW of pump power and the temperature-related power drop is determined to 8.8 W/K. The presented work is believed to be the first multi-kilowatt-class resonantly diode-pumped Er(3+):YAG laser.