Structural, thermal and spectroscopic properties of highly Er3+-doped novel oxyfluoride glasses for photonic application

The Er3+-doped novel oxyfluoride glasses of composition (43 − x)SiO2–10Al2O3–24LiF–23SrF2–xEr2O3, where x = 1.0, 2.0, 4.0 and 6.0 mol%, have been prepared by conventional melt quenching technique and are characterized through X-ray diffraction (XRD), differential thermal analysis (DTA), Raman, Fourier transform infrared (FT-IR) analysis, optical absorption spectra, visible (vis) and near-infrared (NIR) emission spectra measurements. Judd–Ofelt (JO) intensity parameters (Ωλ, λ = 2, 4 and 6) have been derived from the absorption spectrum of 1.0 mol% Er2O3 doped glass and are in turn used to calculate radiative properties for the important luminescent levels of Er3+ ions. The studied glasses show intense green and weak red visible emissions under 365 nm excitation. The decrease in visible emission intensities with concentration of Er3+ ions has been explained due to energy transfer processes between Er3+ ions. Upon excitation at 980 nm laser diode, an intense 1.53 μm NIR emission has been observed with the maximum full width at half maximum (FWHM) for Er3+-doped oxyfluoride glasses. The higher Er3+ ion doping capability and relatively high gain and broad emission at 1.5 μm are the most notable features of these glasses to realize efficient short-length optical amplifiers.