Metalorganic magnetron sputtering (MOMS) technology has been applied to the growth of epitaxial GaSb layers on GaAs (001). Optical studies are performed on a series of GaSb/GaAs samples grown under different growth conditions. Raman scattering measurements indicated the improvement of the crystalline quality of the GaSb thin film from the interface toward the surface with decreasing substrate growth temperature from 480 degrees C to 400 degrees C. Fourier transform infrared (FTIR) reflectance revealed the possible existence of an intermixed GaSb-GaAs layer near the interface. In UV reflectance spectra, the shapes of the high energy transition bands were found to be associated with the Gash film quality. (c) 2007 Elsevier B.V. All rights reserved.