Diode-pumped self-frequency-doubling Nd : GdCa4O(BO3)(3) lasers: toward green microchip lasers

An output power of 115 mW at 545 nm has been obtained from a diode-pumped s elf-frequency doubling Nd:GdCa4O(BO3)(3) laser in a stable cavity. The infr ared emission of the laser was found to be 1091 nm, not the 1060 nm that wa s expected when the highest line of the fluorescence spectrum was considere d. We have demonstrated that the emission at 1091 nm was caused by the temp erature increase at the focus of the pump beam. We demonstrated also, for w hat we believe was the first time, lasing operation of Nd:GdCOB in a plano- plano cavity and obtained an output power of 22 mW at 545 nm. To our knowle dge, this is the highest output power ever reported with a self-frequency-d oubling crystal in a plano-plano cavity. (C) 2000 Optical Society of Americ a [S0740-3224(00)00409-4].