Spectroscopic and optical investigations on Er3+ ions doped alkali cadmium phosphate glasses for laser applications.

• Er3+- doped alkali cadmium phosphate glasses are prepared using traditional melt quenching technique. • Judd–Ofelt theory is used to investigate the radiative transitions of Er3+ ions. • The high values of the branching ratios and lifetimes of the studied glasses indicate their good suitability for laser and optical amplifier applications. • The gain coefficient profile covers the two important communication bands: the conventional band (1530–1565 nm) and the long band (1565–1625 nm). • The studied glasses have the potential to design erbium doped fibre amplifiers for wavelength division multiplexing network system applications. Alkali cadmium phosphate glasses doped with erbium ions were prepared by traditional melt - quenching technique. The FTIR and Raman spectroscopies were performed and employed to investigate the structural changes of the glass network doped with different concentrations of Er3+ ions. The UV–Vis–NIR spectroscopy was used to investigate the optical absorption spectra, optical bandgaps, refractive indices, and related parameters. The Judd – Ofelt (J – O) theory was used to explain the structural changes and to determine the bonds nature in the studied glasses by calculating the intensity parameters Ω 2 , Ω 4 , and Ω 6. The J – O intensity parameters followed the trend of Ω 2 > Ω 6 > Ω 4 and were used to evaluate some radiative parameters such as electric and magnetic radiative transition probabilities, branching ratios, and radiative lifetimes for the excited levels of the Er3+ ions. The absorption and emission cross-sections for the 4I 13/2 → 4I 15/2 transition of Er3+ ions were studied, and the gain coefficient was calculated. The higher values of the branching ratios (≥ 0.5) and lifetimes of the present glasses indicate their good suitability for lasers and amplifiers applications. [ABSTRACT FROM AUTHOR]