Explication of the luminescent and optically active RE3+ triply-doped silica phosphate glass films for photonic applications

The multi-component silicate glass films triply-doped with Er³⁺/Yb³⁺/Nd³⁺ were fabricated by spin coating technique. X-ray diffraction revealed a cristobalite phase in the glasses doped above 0.6 mol% of Nd³⁺. The transparency of the films increases with the addition of the co-dopant, due to the increase in optical band gap by the Burstein-Moss shift. The high value of the correlated color temperature of the blue emission indicates enhanced visual perception, suggestive of cool blue film lasers. The red emission from upconversion exhibits potentiality for flat display panels. The gain cross-section of the glass with 0.6 mol% of Nd³⁺ was 13.54 $\times {10}^{-20}$ cm² which makes it ideal for NIR film lasers in the S-band region. The Inokuti-Hirayama model predicts luminescence quenching due to dipole-dipole interactions in the glasses co-doped beyond 0.6 mol% of Nd³⁺. The $4F_{9/2}\to 4I_{13/2}$ transition observed in the films, suggests their suitability for O + E + S band NIR film lasers in telecommunication sectors.