We demonstrate how an adequate choice of growth conditions and GaAs/AlGaAs superlattice series leads to a desired refractive index profile and to confinement of light at the cusp of a planarized structure over a previously photolithographically etched groove. Waveguiding at 1.52 &mgr;m wavelength with measured propagation losses of 1.5 dB/cm was obtained in these structures. The effect of growth parameters is discussed and potential applications of this concept to other structures suitable for guided‐wave devices are proposed.