Patterning of the second-order susceptibility of an asymmetric quantum well waveguide by ion implantation enhanced quantum well intermixing

We presents measurements of the intermixing-induced changes in second harmonic generation (SHG) efficiency of an asymmetric quantum well (AQW) superlattice waveguide after a patterned ion implantation. Determining the second order nonlinear optical susceptibility for SHG in intermixed AQWs provides useful information for WDM wavelength conversion, because the susceptibility for SHG is similar to the susceptibility for DFG when the signal and difference frequencies are almost equal, as is the case for WDM applications. Each AQW consists of a 2.7-nm GaAs well coupled to a 1.5-nm GaAs well through a 1.2-nm AlGaAs layer, and the coupled well pairs are separated by 16.0-nm AlGaAs barriers.