  Nd doped phosphate glasses have been studied before and after gamma
irradiation in order to understand the effect of glass composition and
radiation induced defects on the optical properties of glasses. UV, Vis
absorption and photoluminescence spectra of these glasses are found strongly
dependent on the composition of glass matrix, particularly on the ratio of
oxygen (O) and neodymium (Nd) concentration obtained from energy dispersive
X-ray spectroscopic (EDX) measurement. Gamma irradiation of glass modifies the
transmission below 700 nm due to generation of some new absorption bands
corresponding to different types of defects. Observations indicate toward
possibility of change in the valence state of Nd3+ to Nd2+ and generation of
oxygen vacancies in glass matrix. EDX and X-ray photoelectron spectroscopic
(XPS) measurements indicate change in the composition of glasses particularly
decrease in the relative concentration of oxygen in glass samples after gamma
irradiation.

Materials Science;Optics