Ultrafast-laser vitrification of laser-written crystalline tracks in oxide glasses

Abstract We report a method of femtosecond laser-induced vitrification of crystalline tracks laser-written in glasses with different crystallization ability including lanthanum borogermanage, barium titanium silicate and lithium niobium silicate glasses. We have found that crystalline tracks consisting of nonlinear optical LaBGeO5 and BaTi2Si2O8 phases corresponding to glass-forming compositions could be readily amorphized by the femtosecond beam, whereas the laser-induced vitrification of a track consisting of LiNbO3 crystalline phase possessing a non-glass-forming composition is more complicated but also possible. The suggested technique provides reversibility of femtosecond laser-induced space-selective crystallization of glasses and thus extends the functionality of the direct laser writing of crystal-in-glass architectures that is important for the fabrication of novel integrated optical components and devices.