  Aluminum gallium arsenide has highly desirable properties for integrated
parametric optical interactions: large material nonlinearities, maturely
established nanoscopic structuring through epitaxial growth and lithography,
and a large band gap for broadband low-loss operation. However, its full
potential for record-strength nonlinear interactions is only released when the
semiconductor is embedded within a dielectric cladding to produce highly
confining waveguides. From simulations of such, we present second and third
order pair generation that could improve upon state-of-the-art quantum optical
sources and make novel regimes of strong parametric photon-photon
nonlinearities accessible.
