Abstract
Ultraviolet-visible UV-Vis diffuse reflectance measurements of irradiated lithium tetra-borate glass have been acquired using. Evolution 600 Spectrophotometer equipped with praying Mantis Diffuse Reflectance Accessory DRA base upon the onset of the diffuse reflectance spectra of the powdered or bulk materials. Also the absorption edge and band gap energies of the prepared glass were determined. The optical energy gap is calculated and found to be (3.0 - 3.5) eV. Which is in close agreement to the one calculated for r = 1/2, i.e. the transition mechanism, is accordingly direct allowed transition. The density increases from 3.1 to 3.9 gm/cm3 for the undoped and doped glass. </p