In this paper reflection index, absorption coefficient and optical constants of p-type silicon wafer with (100) orientation have been experimentally studied by using reflection spectrum from silicon surface. This wafer has been used as a substrate for fabrication of waveguide, so its optical properties have certain importance. In this paper, optical constants of Si wafer is calculated by using Kramers-Kronig method and reflection spectrum experimental data and then our results are compared with some references. The results have good agreement between optical constants of the references and reflection spectrum experimental data and calculated for existence sample in the Lab by using Kramers-Kronig method.
