Cosolvent-free sol–gel synthesis of rare-earth and aluminum codoped monolithic silica glasses

Abstract

A cosolvent-free sol–gel method to synthesize monolithic silica glasses containing both of rare-earth and aluminum ions has been studied. Fracture during drying and bloating during sintering are significantly suppressed by forming macroporous wet gels via macroscopic phase separation in parallel with gelation. The resultant rare-earth and aluminum codoped silica glasses exhibit good visible transparency, suggesting an improvement of dispersion of rare-earth ions in these glasses. The aluminum codoping increases the photoluminescence efficiency in glasses doped with Nd³⁺ ions.