Recent development on laser technique of internal engraving in glass

The laser technique of internal engraving in glass has been developed in two stages, namely, traditional white internal engraving and modern colored internal engraving. Traditional white internal engraving is formed by scanning pulsed laser when the light intensity at the focal point inside the transparent glass is much higher than the glass damage threshold, resulting in the formation of micro-cracks near the focal point of the laser beam. Three-dimensional white color internal engraving is realized due to the light scattering of the micro-cracks. The laser techniques of modern colored glass internal engraving involve space-selective control of color centers, valence state manipulation and precipitation of metal nano-particles. Recent developments on the laser techniques of glass internal engrave are introduced, and the future studies are discussed