Comparison of cw laser performance of Nd:KGW, Nd:YAG, Nd:BEL, and Nd:YVO4 under laser diode pumping

crystals under low-power laser diode end-pumping. Output power dependencies on the pump power and the pump wavelength of these diode-pumped solid state lasers were investigated. The high Nd3+ concentration of the Nd:KGW samples used in our measurements as well as up-conversion and exited-state absorption processes in Nd:KGW cause the reduced laser output power dependence on the pump wavelength which was experimentally observed. At pump levels up to 270 mW a slope efficiency of ηsl≈46% was reached for the Nd:KGW laser. Nd:KGW microchip laser operation with a slope efficiency of ηsl≈50% was demonstrated. Thermal lensing in Nd:KGW at pump powers up to 3 W was measured.