Finite element simulation and experimental study on uniformity adjustment of multi physical field in photo-thermo-refractive glass

This study aims to address the crystal non-uniformity in photo-thermo-refractive (PTR) glass by exploring the synergistic regulation of multiple physical fields in photo-thermo-induced crystallization processes through simulations and experimental validation. This study reveals that Ce^3 + doping concentration affects the attenuation gradient of the 325 nm light field, with 0.013 mol% identified as the optimal concentration for balancing light field penetration and photosensitive reaction. By optimizing the heating/cooling rate and forced convection rate, the internal temperature gradient of PTR glass can be well controlled. Under the moderate concentration of Ce³⁺ (0.013 mol%) doping and optimized thermal treatment parameters, small (40–60 nm) and density (1.2–1.8 ×10²⁰ m⁻³) NaF grains can be obtained in a large (75 mm × 75 mm × 2 mm) PTR glass, with the mass fraction fluctuating less than 0.05 wt%. These findings offer valuable insights for the fabrication of large and high-quality optical devices based on PTR glass.