Analysis of normal incidence spectral reflectivity of excimer laser annealed &agr;‐Si:H shows that the annealed material can be modeled as a stratified system comprising a large‐grained polycrystalline layer, a fine grained polycrystalline layer, and residual amorphous silicon in agreement with transmission electron microscopy. Optically, the large‐grained poly‐Si behaves as single‐crystal silicon and the fine‐grained material is modeled, using effective medium theory, as a mixture of single‐crystal silicon and amorphous silicon. ©1996 American Institute of Physics.