Abstract
The accurate refractive indices in visible range and their Sellmeier equations have been obtained for a series of LiNbO3: Mg (5 mol%) crystals with Ti or Nd doping. The phase matching angle for 1.064μm calculated by Sellmeier equation gives good agreement with experimental value. The TiO2 and Nd2O3 doping cause the decrease of the birefringence and the increase of the phase matching angle. The conversion efficiency is enhanced by TiO2 doping. The second harmonic generator with conversion efficiency of more than 44% has been achieved at room temperature with phase matching angle close to 90°.