Optical properties and spectroscopic study of different modifier based Pr3 +:LiFB glasses as optical amplifiers

• Different Pr3 + doped lithium-fluoro-borate (LiFB) glasses were investigated.
• The structural properties of Pr3 + doped different LiFB glasses were characterized by XRD, SEM and FTIR techniques.
• Judd-Ofelt parameters Ωλ (λ = 2, 4 and 6) for studied glasses are reported and these are compared with other glass matrices.
• Pr3 + doped different LiFB glasses exhibits intense Pr3 + emission (3P0 → 3H4) peaking at 488 nm.

In this paper, we report the preparation and optical characterization of Pr3 + doped lithium fluoro borate (LiFB) glasses for six different chemical compositions of Li2B4O7-BaF2-NaF-MO (where M = Mg, Ca, Cd and Pb), Li2B4O7-BaF2-NaF-MgO-CaO and Li2B4O7-BaF2-NaF-CdO-PbO. The structural and optical properties of these glasses were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), optical absorption and photoluminescence techniques. The optical absorption spectra of Pr3 + ions in LiFB glasses have been recorded in the UV–VIS-NIR region. The optical absorption data are used to calculate various spectroscopic parameters such as Racah (E1, E2, E3) and spin-orbit interaction (ξ4f) parameters. Judd-Ofelt (J-O) (Ωλ where λ = 2, 4 and 6) intensity parameters were determined by applying J-O theory, which in turn used to calculate the radiative properties such as radiative transition probabilities (A), radiative lifetimes (τR), integrated absorption cross-sections (Σ) and branching ratios (βr) for all emission levels of Pr3 + ion in different LiFB glass matrices. By using the J-O theory and luminescence parameters, stimulated emission cross sections (σp) of prominent transitions, 3P0 → 3H4 and 1D2 → 3H4 of Pr3 + ion in all LiFB glasses were calculated. 3P0 → 3H4 possesses higher branching ratios and stimulated emission cross-sections for the Pr3 +:LiFB(Mg-Ca) glass, which can be used as a best laser excitation. The optical gain parameter (σpxτR) was noticed higher in Pr3 +:LiFB(Mg-Ca) and Pr3 +:LiFB(Cd-Pb) glasses for the transition 3P0→ 3H4 transition, and these glasses have potential for optical amplification at 488 nm wavelength.