Influences of Mn2+ ions, and Mn2+–Yb3+ dimer on the optical band gaps and bandwidth flatness of near-infrared emissions of Ho3+/Tm3+, Ho3+/Tm3+/Yb3+ co-doped calcium aluminosilicate glasses

Abstract

We investigate and report the influences of Mn2+−Yb3+ dimer on the optical band gaps and bandwidth flatness of near-infrared (NIR) emission spectra of Ho3+/Tm3+, and Ho3+/Tm3+/Yb3+ co-doped CaO–Al2O3–SiO2 (CAS) calcium aluminosilicate glasses. Differential thermal analysis (DTA) and Energy dispersive X-ray spectroscopy (EDS) analyzes were performed to determine temperature values for heat treatment and elemental composition existing in the glass materials, respectively. NIR emission spectra of Ho3+/Tm3+/Yb3+ co-doped CAS glasses with a bandwidth of ∼450 nm using a 980 nm laser diode (LD) as the excitation resource was identified. Influences of Mn2+ ions and Mn2+–Yb3+ dimer on the direct/indirect optical band gaps, and bandwidth flatness of NIR emission of Ho3+/Tm3+/Yb3+ co-doped were investigated. At the same time, we determined the optimal Mn2+:Yb3+concentration ratio for the best flatness of the bandwidth NIR emission of Ho3+/Tm3+/Yb3+ co-doped CAS glasses.