Multiple-wavelength second-harmonic generation in aperiodic optical superlattices

We present a kind of aperiodic structure for the generation of multiple-wavelength second harmonic in a quasi-phase-matching scheme. In order to confirm its efficiency, a LiTaO3 superlattice with such an aperiodic domain-inverted structure was designed and fabricated. The second-harmonic generation at four present wavelengths was experimentally demonstrated from the superlattice with high and nearly equal conversion efficiencies. The tested result is in good agreement with theoretical consideration. The method may be used for the design of optical superlattices to construct multiple-wavelength lasers and wavelength converters for all-optical network.