Advancing Waveguide Laser Performance: An In‐Depth Analysis of the Physical, Thermal, and Spectroscopic Properties of Sm3+‐Doped Borotellurite Glasses

ABSTRACT A series of Sm 3+ ‐doped potassium borotellurite (TBK) glass samples are fabricated using melt quenching technique. Differential thermal analysis is conducted to understand thermal stability of glasses, with increasing glass transition temperature and onset crystallization indicating enhanced network connectivity within the glass matrix as Sm 3+ content rises. Optical absorption measurements show that both direct and indirect band gaps increase with the higher concentration of Sm 3+ ions, whereas refractive index decreases. Raman spectral analysis has been done to investigate the presence of TeO 4 , TeO 3 , and TeO 3 + 1 structural units. By analyzing Judd–Ofelt intensity parameters (Ω 2,4,6 × 10 −20 cm 2 ), derived from experimental oscillator strengths of absorption spectra, the radiative properties of fluorescent transitions 6 H 5/2 → 6 F 3/2 , 6 F 5/2 , 6 F 7/2 , and 6 F 9/2 of Sm 3+ ions in TBK glasses are estimated, offering valuable insight into the potential of these materials for visible laser applications. Photoluminescence emission spectra depict maximum intensity for 4 G 5/2 → 6 H 7/2 transition at 602 nm, characteristic of Sm 3+ ions emitting in the reddish‐orange region. The radiative transition probability and branching ratio for 4 G 5/2 → 6 H 7/2 transition also dominate among all other transitions. The CIE chromaticity coordinates of the Sm 3+ ‐doped TBK also confirms the emission in orange‐red color.