We report spectroscopic ellipsometry (SE) studies on(Si)2(Ge)12,(Si)6(Ge)2,and(Si)12(Ge)2short period superlattices (SLs) whose optical response has not been reported yet. Multilayer calculations enabled us to determine the dielectric response of the superlattice layers. We report the clear observation of splitting of theE2peak in(Si)m(Ge)nsuperlattices contrary to the previous SE report that the separation was observed only in larger period SLs. ©1997 American Institute of Physics.