Improved dispersion equation for MgO:LiNbO/sub 3/ crystal in the infrared spectral range derived from sum and difference frequency mixing

Phase matching angles for sum and difference frequency mixing in a 7% MgO:LiNbO/sub 3/ crystal of the radiation of a Ti:Sapphire laser and the radiation of 2.2 to 3.4 /spl mu/m from a Raman shifter are used to determine the refractive indices of the crystal. A dispersion equation accurate in the mid-infrared spectral range as well as in the visible and near infrared range is firstly given. Based on this result the phase matching characteristic of a mid-infrared optical parametric generator using 7% MgO:LiNbO/sub 3/ crystal is described.