Investigation of Nd:YVO4/YVO4 composite crystal and its laser performance pumped by a fiber coupled diode laser

Thermal effect control is critical to scale the output power of diode end-pumping solid lasers to several watts up and beyond. Diffusion bonding crystal has been demonstrated to be an effective method to relieve the thermal lens for the end-pumping laser crystal. The temperature distribution and thermal lens in Nd:YVO4/YVO4 composite crystal was numerically analyzed and compared with that of Nd:YVO4 crystal in this paper. The end-pumping Nd:YVO4/YVO4 composite crystal laser was set up and tested with z cavity. The maximum output power of 9.87 W at 1064 nm and 6.14 W at 532 nm were obtained at the pumping power of 16.5 W. The highest optical–optical conversion efficiencies were up to 60% at 1064 nm and 40% at 532 nm, respectively.