An efficient sol–gel process for synthesizing Bi-doped silica glasses

Sol−gel method is a promising technique for the low-temperature synthesis of optical functional glasses. However, several key technical challenges remain unresolved, including long preparation cycles, low yield rates, limited doping capabilities, and difficulties in hydroxyl removal, which impede its advancement and practical applications. Herein, we proposed a novel sol−gel process for efficient fabrication of optical silica glasses, successfully addressing these challenges. By using a two-step preparation strategy with HF and HCl as co-catalysts, a series of crack-free high-concentration uniform Bi-doped gel was synthesized. Vitrification of the gel was achieved via rapid quenching following degreasing. The proposed method demonstrates universal applicability for the cost-effective fabrication of high-gain optical functional glass. The prepared Bi-doped glass exhibits high quenching concentration, showing promise for applications in the development of high-gain optical fibers and related devices.