Comparing Thermally-Induced Beam Degradation for High-Power Lissajous Modes by a Diode-End-Pumped YVO4 Laser with Different Nd-Dopant Concentration

Beam degradation of Lissajous structured modes induced by thermal effects was explored by a high-power diode-pumped YVO
4
laser. Experimental results reveal that the generated Lissajous patterns will deform significantly during power scaling when using a higher Nd-doping level gain crystal due to stronger thermal loading. By further performing astigmatic mode conversion, the corresponding trochoidal beams are confirmed to be greatly influenced by the thermal aberration of the gain medium.