Fracture characteristics of ceramic Nd:YAG.

The fracture of laser material in a ceramic Nd:YAG laser pumped by a fiber-coupled laser diode was analyzed. The fracture of the laser material was found to occur when the critical temperature difference between the center of the material and the surface exceeded 355°C. To quantitatively analyze the material fracture, the heat-generation length and heat-generation radius of the laser material were calculated and the critical pump power per unit volume was examined. Under lasing and non-lasing conditions, the fracture of laser material occurred at 24.41 kW/cm(3) and 19.53 kW/cm(3), respectively, for 2 at.% ceramic Nd:YAG and 25.57 kW/cm(3) and 20.47 kW/cm(3), respectively, for 4 at.% ceramic Nd:YAG.