Contents lists available at ScienceDirect Journal of Luminescence journal homepage: www.elsevier.com/locate/jlumin Green and near infrared emission of Er 3+ doped PZS and PZC glasses B. Afef a , Moteb M. Alqahtani b , H.H. Hegazy b,c , E. Yousef b,c , K. Damak a, ⁎ , R. Maâlej a a Georesources Materials Environment and Global Changes Laboratory (GEOGLOB), Faculty of Sciences of Sfax, University of Sfax, 3018 Sfax, Tunisia b Research Center for Advanced Materials Science (RCAMS), King Khalid, University, P.O. Box 9004, Abha 61413, Saudi Arabia c Department of Physics, Faculty of Sciences, King Khalid University, P.O. Box 9004, Abha, Saudi Arabia ARTICLE INFO Keywords: Phosphate glasses Er 3+ ions Optical spectroscopy Judd-Ofelt analysis Luminescence ABSTRACT The glasses with composition 50P 2 O 5 -30ZnO-20SrO (PZS) in mol% doped with 30,000 ppm Er 2 O 3 and 50P 2 O 5 - 30ZnO-20CdO (PZC) in mol% doped with 30,000 ppm Er 2 O 3 were prepared by quenching -melting method. Spectroscopic and Judd-Ofelt (J-O) parameters, Ω t , of these glasses were evaluated. Moreover, different radiative properties and optical energy gap of prepared glass were calculated. The emission spectra of the PZC-30000Er and PZS-30000Er glasses excited at 490 nm show an important emission band at 550 nm and the emission cross- section σ λ () e for the resonant transition at 1530 nm is equal × 0.47 10 cm 20 2 for PZC glass and × 0.39 10 cm 20 2 for PZS glass. Optical gain coefficient, G(λ), of the prepared glass were calculated and it is obtained that PZC glass lasing would be achieved at 1550 nm for a population inversion about 40% and at 1510 nm in the case of PZS glass. The structure of prepared glass investigated by using Raman spectra, has shown that SrO creates more bridging oxygen in the linkage of P 2 O 5 - ZnO glass network compared with CdO in the same glass matrix. In conclusion, these glasses can be used to generate green light and they can be useful for laser applications in the NIR region. 1. Introduction Presently, only rare earth ions (RE) are known to perform the lasing action in glassy hosts [1], because it is well known that their optical properties depend on their local environment in which the ions are incorporated. In other words, the surrounding ligand field can have a considerable influence on the optical absorption and emission cross- section, which are the key factors that control the optical properties of a RE ion in any host matrix [2,3]. So, by changing the glass matrix en- vironment, the spectroscopic properties of Er 3+ ions can be optimized. So far, chloride, sulfide and fluoride glasses doped with Er 3+ ions have proved to be attractive glass hosts for obtaining efficient infrared and up-conversion emissions [4,5]. However, poor chemical durability and thermal stability limit the application of these non-oxide glasses. Thus, optimization and designing of optical glasses with good thermal stability and durability become more and more significant in making high performance optical devices [6,7]. Compared with these non-oxide glasses, oxide glasses which include borate, phosphate, silicate, ger- manate, tellurite, gallate and heavy metal oxide glasses have higher stability and good chemical durability [8,9]. Among these glass hosts, phosphate glass is an excellent host for the amplification of RE ion lu- minescence due to its high gain co-efficient, its high RE ion solubility, low upconversion emission and low probability of energy back transfer [10]. Thus our focus in the present paper is to demonstrate the effect of phosphate content on the optical and structural properties of glass by determining the optical band gap, refractive index and JO parameters to explain their compositional dependence. Also,to evaluate radiative properties for lasers materials such as branching ratios, radiative life- times and emission cross sections the gain emission, using Judd-Ofelt (J-O) and Mc-Cumber theories. 2. Experimental procedure The present phosphate glasses with composition 50P 2 O 5 – 30ZnO- 20SrO doped with 30,000 ppmEr 2 O 3 (PZS-30000Er) and 50P 2 O 5 – 30ZnO- 20 CdO doped with 30,000 ppmEr 2 O 3 (PZC-30000Er) were prepared by using quenching melt method. They were melted in silica crucibles at 1200 °C, after that the composites cast in a steel mold at 30 °C followed by annealing at 420 °C for 2 h. The value of density for present glasses was determined by using helium gas pycnometer (Model: UltraPyc 1200e). The nature of these glasses examined by X-ray diffraction (XRD), (Siemens D 6000) using CuKα radiation at 40 kV in the 2θ range from 5 to 90° and scanning electron microscopy (SEM), a JEOL ™ Model JSM-T330 operating at 25 kV was used. The absorption spectra were measured by using UV–vis–NIR double beam http://dx.doi.org/10.1016/j.jlumin.2017.09.040 Received 30 January 2017; Received in revised form 16 September 2017; Accepted 18 September 2017 ⁎ Corresponding author. E-mail addresses: Kamel.Damak@fss.rnu.tn, Kamel.Damak@ipeis.usf.tn (K. Damak). Journal of Luminescence xxx (xxxx) xxx–xxx 0022-2313/ © 2017 Published by Elsevier B.V. Please cite this article as: Belguith, A., Journal of Luminescence (2017), http://dx.doi.org/10.1016/j.jlumin.2017.09.040