Spectroscopic analysis of Ho3+ transitions in different modifier oxide based lithium–fluoro-borate glasses

Abstract

In recent investigations it was observed that the presence of different structural groups in borate glasses was favorable for spectroscopic investigations of rare earth doped borate glasses. Consequent to these observations, the heavy metal fluoride glasses doped with Ho3+ ions received much attention due to their wide transparency in the ultraviolet to infrared region. Keeping these observations in view, the present paper makes an attempt to present spectral investigations of Ho3+ doped lithium–fluoro-borate glasses of the compositions Li2B4O7–BaF2–NaF–MO (where M=Mg, Ca, Cd and Pb), Li2B4O7–BaF2–NaF–MgO–CaO and Li2B4O7–BaF2–NaF–CdO–PbO. These rare earth doped glasses were synthesized by melt quenching technique and an investigation was carried out to observe the structural (SEM and FT-IR) and optical (absorption and luminescence) properties. The paper also aims at the determination of three phenomenological Judd–Ofelt intensity parameters and special attention was paid to study the emission properties by employing the J–O intensity parameters. The visible emission spectra of Ho3+ ion in different lithium–fluoro-borate glasses were recorded by exciting the samples at 409nm. The results revealed that among all the glass matrices, cadmium glass matrix have shown higher stimulated emission cross-section, which indicates that this is a good lasing material at this wavelength and highly useful for laser excitation.