Study on the optical properties of new multi-waveband transmission fluoroaluminate-tellurite glasses

A new mid-infrared fluoroaluminate-tellurite glass with low hydroxyl absorption coefficient and high visible-infrared transmittance was fabricated by the high temperature melt casting method. The melting equipment was innovatively designed by placing lift furnaces in the glove box filled with dry oxygen to assure waterless preparation. The glass prepared in the glove box had low hydroxyl absorption coefficients (0.09 cm⁻¹), validating the effectiveness of the water removal equipment. The glass was obtained with excellent thermal stability (T_g > 450 °C) and good resistance to crystallization based on thermodynamic analysis (ΔT > 100 °C). The transmittance of glass maintained 80–91.30 % from 371 to 5572 nm, achieving high transmittance in multi-waveband. The glass had excellent optical and composition homogeneity indicated by refractive index and EDAX. The results showed that this glass had high thermal stability, visible-infrared transmittance and optical homogeneity, making it a good candidate for multi-waveband optical window materials.