Nanosecond Near-Infrared Laser Discoloration of Gamma Irradiated Silicate Glasses

Abstract

Due to its non-crystalline, amorphous structure, glass is particularly susceptible to radiation-induced coloration/discoloration. Oxide glasses reveal a variety of colors depending upon their composition when exposed to high energy radiations such as gamma and X-rays, and the colors induced have been explained in terms of the formation of color centers. These effects can be reversed by heating or upon exposure to light at wavelengths corresponding to the absorption region of the color centers, a process known as discoloration. Laser can be an efficient process for accomplish this in a localized manner. The aim of this work was to study local discoloration of gamma radiation exposed silicate glasses by application of a nanosecond pulses infrared laser beam. Experimental results validated a numerical model and proved the viability of local laser discoloration of gamma ray irradiated silicate glasses. Although there has been much work focusing the creation and destruction of color centers in glasses, to the best of our knowledge, the application of infrared laser radiation in the local annealing of gamma irradiated glasses was for the first time explored.