Improvement in 1.53-μm-band fluorescence of Er3+/Yb3+-codoped borate glasses based on infrared energy transfer

Abstract

Er3+/Yb3+-codoped borate glass consisting of B2O3–WO3–ZnO–Y2O3 was synthesized as a potential gain medium for an Er3+-doped fiber amplifier (EDFA). X-ray diffraction (XRD) patterns and Raman spectra were characterized to investigate the structural behavior of the glass host, and absorption spectra were recorded to investigate the spectroscopic properties of the Er3+/Yb3+-codoped borate glasses according to the Judd–Ofelt theory. The 1.53-μm-band emission spectra of Er3+ under 980-nm excitation were measured to verify the process of energy transfer (ET) from Yb3+ to Er3+, and the decay lifetimes of Yb3+:1020-nm emission were determined to evaluate the ET efficiency (ETE) between Yb3+ and Er3+. The results indicate that a broad 1.53-μm-band emission occurs for Er3+, with a full width at half maximum (FWHM) of approximately 82 nm. Moreover, the emission intensity increases by approximately 66.7% in Er3+/Yb3+-codoped borate glass containing 10.0 mol% Yb3+, which is ascribed to the efficiency ETE of Yb3+:2F5/2 + 4I15/2 → Yb3+:2F7/2 + Er3+:4I11/2. Compared with the previously reported glass systems, the prepared borate glasses have the typical features, including high gain and broad emission at 1.53-μm, which provide a new route to improve the signal gain in the C-band and further develop the short-length optical amplifiers.