Optical Properties of Zinc Phosphate Glass Doped With Aluminum Oxide for Optical Filter

Phosphate glass system doped with Al2O3 of chemical formula 49.5% P2O5-20%Na2O-(30-x)%ZnO-x%Al2O3-0.5%CuO (x=0, 2.5, 5, 7.5, 10) was prepared by conventional melt quenching technique. XRD analysis shows the glassy nature of the prepared samples. The measured density and calculated molar volume reveal nonlinear dependence, however follow opposite trend. Optical transmittance of all prepared samples show absorption edge. Obtained optical transmittance was used to estimate band gap Eg. Eg shows nonlinear dependence on the Al content. The analysis of optical data reveals the indirect transmission mechanism. Refractive index and dielectric constant show a slight change.