We have carried out a detailed structural and optical characterization of Ga0.47In0.53As/InP multiple quantum wells grown by chemical beam epitaxy using a well‐defined sequence of growth interruption times between successive layers. These growth interruption times result in the formation of interfacial layers which drastically alter the structural properties of Ga0.47In0.53As/InP multiple quantum wells. An analysis of double‐crystal x‐ray diffraction data reveals that exposure of InP to arsine for 2 s is sufficient to create approximately 3 monolayers of InAs0.55P0.45ternary under biaxial compressive strain at the InP/Ga047In0.53As interface. Moreover, exposure of Ga0.47In0.53As to phosphine for 2 s results in the formation of approximately 2 monolayers of Ga0.48In0.52As0.21P0.79quaternary under biaxial tensile strain at the Ga0.47In0.53As/InP interface. We find that long exposures to hydrides (over 5 s) rather than short ones give rise to interfacial layers with less compositional disorder and/or thickness fluctuation. Moreover, photoluminescence and absorption spectroscopy data reveal the negligible effect of InAsxP1−xand GaxIn1−xAsyP1−yinterfacial layers on the emission and optical absorption properties of Ga0.47In0.53As/InP multiple quantum wells with sufficiently thick Ga0.47In0.53As layers. ©1996 American Institute of Physics.