Femtosecond laser induced space-selective crystallization in lithium aluminosilicate glass and erasure of micro-crystals in the glass-ceramics

Spatially selective crystallization inside glass induced by femtosecond laser irradiation holds significant potential in encrypted data storage. In this work, we demonstrate spatially selective crystallization of multiple crystalline phases in lithium aluminosilicate glass. The formation of lithium metasilicate (Li 2 SiO 3 ), lithium disilicate (Li 2 Si 2 O 5 ) and petalite (LiAlSi 4 O 10 ) was confirmed by DSC, XRD, and Raman spectroscopy. The emergence of distinct crystalline phases was found to depend on laser parameters under static irradiation and line scanning modes. Low-temperature phase Li 2 SiO 3 crystals preferentially form at the periphery of the laser modified region, while a gradual phase transition to the high-temperature Li 2 Si 2 O 5 occurs closer to the focal center, and the crystallized region exhibited nonlinear optical frequency-conversion capability. Moreover, we further realize the spatially selective erasure of micro-crystals in the pre-heat-treated glass. These findings may pave the way for future applications in integrated optics and functional glass-ceramics.