Calculation of the dispersion of the electro-optical and second harmonic coefficients from the refractive index dispersion

•We model the λλ-dispersion of the EO and SHG coefficients.•Solely the measurement of the coefficient at one wavelength is required.•We report the calculated behavior of various coefficients in several NLO materials.•The model is applied to the high and low frequency electro-optic coefficients.

The relationships of the wavelength dependence of both the electro-optic and second harmonic generation coefficients are established within the same model applied to nonlinear optical materials. It is demonstrated that the dispersion of these coefficients can be obtained from the own dependence of the refractive indices only, without any fitted parameter. Solely the measurement of the coefficient at one wavelength is required within this approach. A very good agreement in the λλ-dependence of electrooptic and second harmonic generation coefficients is achieved between calculated values and experimental data in SBN, DAST, KTP and KNbO3 crystals.