Effect of electro-optic modulation on coupled quasi-phase-matched frequency conversion

The electro-optic effect can be employed to modulate the refractive index of an optical superlattice. In coupled quasi-phase matched processes, this modulation will introduce quasi-phase mismatches and result in energy redistribution among the optical waves. Numerical results indicate that an efficient third harmonic in a periodic or quasi-periodic superlattice can be achieved by varying the external dc electric field. This method provides a simple and convenient way to control the efficiencies of frequency conversion.