InP substrate orientation (100), (110)A, (110)B, (111)A, (111)B, (112)A and (112)B significantly affects phase decomposition and ordering. Through TEM, AFM and photoreflectance investigations, the effect of MBE growth on the above surfaces has been determined. Features related to phase decomposition due to (110)A, (111)B and (112)B surfaces have been identified. Anisotropy in optical transitions in samples grown on (110)A and (110)B InP has been identified through photoreflectance investigations.