Strained InGaAs/GaAs quantum wells were grown on nonplanar substrates by molecular beam epitaxy and studied by scanning electron microscopy and low temperature spatially and spectrally resolved cathodoluminescence spectroscopy. For (100) ridges and grooves formed with (311)Asidewalls, almost complete removal of In from the strained quantum wells on the (311)Afacet is observed. Corresponding increases of In content in the quantum wells grown on the (100) facets indicate that most if not all of the In is displaced from the (311)Afacet via interplanar adatom migration. Ga adatom migration is also observed under our growth conditions such that quantum wells grown nominally near the critical layer thickness on structures less than ≂2.5 μm wide are no longer pseudomorphically strained, as detected by luminescence linewidth analysis. We present the first results of strained InGaAs/GaAs index guided injection lasers grown by single‐step molecular beam epitaxy over nonplanar substrates and show that differences greater than 50 meV in the effective band gap of a 70 Å quantum well can be achieved between the gain region and the nonabsorbing waveguide without relaxing the strain. Room temperature threshold currents as low as 6 mA for 4 μm×750 μm uncoated devices lasing continuously at a wavelength of 1.01 μm have been achieved.