We investigate the potential of fabricating thermally stable refractive index contrasts using femtosecond (fs) near‐infrared (IR) radiation in aluminosilicate glasses. A set of pure SiO₂‐Al₂O₃ glasses are manufactured, characterized (density and Raman), and investigated after being irradiated by fs laser within the Type II regime. The formation of nanogratings is identified and studied using quantitative birefringence measurements. Their thermal stability is then investigated through 30 minutes step isochronal annealing (up to 1250°C). For both SiO₂ and 50SiO₂‐50Al₂O₃ compositions, the normalized birefringence does not decrease when tested up to 1100°C, while for the 4,6 mol% GeO₂‐SiO₂ erased for 20% at 1000°C.

中文翻译：

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飞秒激光直接写入SiO2-Al2O3二元玻璃和II型永久性修饰的热稳定性

我们研究了在铝硅酸盐玻璃中使用飞秒（fs）近红外（IR）辐射制造热稳定折射率对比的潜力。制造了一组纯SiO ₂ -Al ₂ O ₃玻璃，进行了表征（密度和拉曼），并在II型范围内用fs激光辐照后进行了研究。使用定量双折射测量来识别和研究纳米光栅的形成。然后，通过30分钟的等时退火（高达1250°C），研究了它们的热稳定性。对于SiO ₂和50SiO ₂ -50Al ₂ O ₃成分，归一化双折射在高达1100°C的温度下测试时不会降低，而对于4,6 mol％的GeO ₂ -SiO ₂在1000°C时擦除了20％。