In this paper we present a systematic investigation of the structural and optical properties of InGaP using a metamorphic InxGa1-xP buffer layer grown on GaP(100) substrates. When grown at 400 degrees C, the simpler constant-composition metamorphic buffer layer has a smoother surface morphology, as compared to that grown at 500 degrees C, and results in comparable structural quality of the top layers as a linearly graded metamorphic buffer layer. In0.5Ga0.5P quantum wells with In0.3Ga0.3P barriers grown on a constant-composition metamorphic buffer layer exhibit room-temperature bright photoluminescence in the amber wavelength at 610 nm. (c) 2005 Elsevier B.V. All rights reserved.