The formation of optical phase structures in the volume of phosphate glasses by means of thermal diffusion caused by the action of femtosecond laser radiation

This paper discusses the physicochemical properties (density, microhardness, thermal effects, electrical conductivity, calculated volumes of fluctuation microvoids, and spectral studies) of phosphate and niobium–phosphate glasses containing lithium, sodium, and potassium oxides. It shows that, when one alkali oxide is replaced by another equivalent one, there is a nonlinear variation of the electric parameters, while all the other parameters vary linearly. Scanning with a femtosecond laser in the volume of lithium (sodium) niobium–phosphate glass produces high-contrast optical elements by means of the diffusion of lithium (sodium) ions from the focal center to the edges and counterdisplacement of niobium from the edges to the center.