Physical, structural and optical studies on Er3+ ions doped zinc bismuth borate glasses for photonic applications

A new series of Er3+ ions doped zinc bismuth borate glasses have been prepared to evaluate and optimize the structural and spectroscopic properties for photonic applications. The physical properties have been determined using density (ρ) and molar volume (VM) values. The structural properties like, boron–boron separation (dB–B), oxygen packing density (OPD) values were evaluated for the interpretation of physical and structural properties. The visible luminescence spectra exhibit strong 4S3/2→4I15/2 emission transition and weak 2H11/2→4I15/2 emission transition corresponding to the band positions at 552 and 534 nm respectively under 488 nm excitation. The Judd-Ofelt (JO) theory has been applied to interpret the local environment of the Er3+ ions site and covalency of the Er–O bond. The various lasing parameters such as stimulated emission cross-section (σPE), experimental and calculated branching ratios (βR) and radiative lifetime (τcal) have been calculated for the 4S3/2→4I15/2 emission transition. The CIE color coordinates of the prepared glasses lay in the green region of the chromaticity diagram thus suggest the fact that intense green emission can be achieved from the Er3+ doped zinc bismuth borate glasses.