Spectroscopic and optical investigations on Er3+/Yb3+co-doped bismuth–boroleadlithium glasses for solid state laser applications

Abstract

Erbium–Ytterbium ions co-doped Bismuth boroleadlithium glasses have been found to be a viable option for a variety of photonics applications. In the present article, a small content of erbium oxide (0.5) and ytterbium (0, 0.5, 1, 1.5 and 2 mol%) assorted with bismuth boroleadlithium glasses were produced using the traditional melt-quenching method. The detailed structural and optical properties of glasses were analyzed through various characterization techniques viz., XRD, FESEM, DTA, FT-IR, Optical absorbance (OA) and Photoluminescence (PL). The results of XRD and SEM confirmed the non-crystalline nature of the glasses and the local structural changes were perceived by FTIR and DTA analysis. From OA data the calculated J-O intensity parameters (Ωλ where λ = 2, 4 and 6) of the present glasses followed the trend Ω2>Ω6>Ω4, it shows that the Yb–O bond has a higher degree of covalency. Moreover, the values (Ω4/Ω6 < 1) of spectroscopic quality factor signifying the suitability of laser transitions. Obtained 4F9/2 → 4I15/2 (red) transition have more intense than 2H11/2 → 4I15/2 (green) transition with co-doped Er/Yb ions. It is also noticed that the luminescence properties enhanced with increasing ytterbium concentration up to 1 mol% and then reduced due to luminescence quenching. CIE chromaticity coordinates and CCT (correlated color temperature) values were measured from the luminescent spectra to estimate the quality of the light emitted for laser generation. Overall, the acquired experimental results of the as-developed glasses revealed their appropriateness for the generation of efficient fiber amplifiers and solid-state lasers.