Quantum wells and artificially structured materials for nonlinear optics

Semiconductor lasers have been successful in covering only a limited portion of the desired spectral regions. New non-linear optical materials based upon semiconductor quantum wells and artificially structured materials greatly enhance the non-linear susceptibility and create possibilities for both new devices to reach these spectral regions and novel structures which can be integrated with the existing lasers. Second harmonic generation with asymmetric quantum wells and approaches for phase matching are described. The potential to extend these concepts into the visible spectral region are also discussed.