Epitaxial orientation-patterning of AlGaAs films for nonlinear optical devices

We have developed an all-epitaxial technique employing GaAs/Ge/GaAs polar-on-nonpolar epitaxy for fabrication of orientation-patterned semiconductor templates, and used it in combination with epitaxial regrowth to produce quasiphasematched nonlinear optical AlGaAs waveguides. We demonstrated second-harmonic generation of 1.55 μm radiation in these devices and found that the measured conversion efficiency (4%/W) is limited by large optical losses attributed to poor regrowth quality of the waveguide layers