El-Sayed EL-ZAIAT^*

Physics Department, Faculty of Science, Ain Shams University, Abbasia 11566, Cairo, Egypt

(Received August 6, 2013; Revised September 16, 2013; Accepted September 19, 2013)

In this work, an expression for the interface reflectance in terms of both the total transmittance and the total reflectance of the glass substrate is derived. Using this expression a nondestructive procedure for deducing the complex refractive index of glass bulk material is suggested. Complex refractive indices of four glassy substrates with different thicknesses and compositions are experimentally measured across a spectral range 200–2000 nm. The errors of measurements for the suggested procedure depend on the reflectance and transmittance errors. They are calculated to be of about ± 2.751× 10^-8 for imaginary and ± 0.008 for real refractive indices. Dispersive parameters of the real refractive indices and optical energy gaps for direct and indirect allowed optical transitions are deduced. Predicted nonlinear refractive indices and susceptibilities are evaluated.

Key words: spectrophotometer, reflectance, transmittance, refractive index, optical properties

^*E-mail address: syelzaiat@hotmail.com