Highly efficient diode-pumped seven-rod resonator with a 3.79-kW output

Thermally stable region of a seven-rod resonator is theoretically investigated. A plane-plane symmetric resonator, where the distance between two neighbor rods is two times of that between the rods and the mirrors, is adopted because of its large stable range. Based on the investigation, a seven-rod resonator with an average output power of 3.79 kW and an optical-to-optical efficiency of 53% is developed.