Thin films of beta barium borate (beta-BBO) were deposited by electron beam physical vapor deposition on MgO(100) substrates. The deposition conditions were optimized so that the thin films would grow preferentially in a c-axis orientation. At a deposition temperature of 650degreesC, thin films grown on a MgO(100) substrate were found to be highly textured, with (001) orientation (c-axis) normal to their surface. The addition of 4 mol % of TiO2 to the BaO-B2O3 system stabilized the beta-BBO crystalline phase without inducing significant variations in the optical properties of the thin films with respect to those of beta-BBO bulk single crystal. The film crystallized in situ at 650degreesC exhibited a maximum effective second harmonic generation coefficient, d(eff), of 1.85 pm/V, which is comparable to the d(22) coefficient of bulk beta-BBO crystal. (C) 2004 American Vacuum Society.