The spectroscopic properties of Er 3+-doped antimony–borate glasses

Abstract

The spectroscopic properties of Er 3+-doped Sb 2O 3–B 2O 3 glass have been investigated for developing 1.55-μm broadband fiber amplifiers and tunable lasers. A broad 1.55-μm near infrared emission peaked at 1527 nm with a full width at half maximum (FWHM) of 91 nm has been obtained for 30Sb 2O 3–69B 2O 3–1Er 2O 2 glass upon excitation of a 980 nm laser diode. This broad luminescence locates in the region of 1440–1650 nm and covers the S, C and L bands. The emission cross-section of the 4I 13/2→ 4I 15/2 transition of Er 3+ ions and the measured lifetime of the 4I 13/2 level of Er 3+ ions are 6.01×10 −21 cm 2 and 0.341 ms, respectively. Based on the electronic polarizability of the oxide ion and optical basicity estimated from the values of refractive index and molar volumes, the covalent bonding character in the local ligand environments around Er 3+ in Sb 2O 3–B 2O 3 glasses increases with increasing Sb 2O 3 content. It is noted that the product of the emission cross-section and the FWHM of the glass, σ e ×FWHM, is as great as 567×10 −28 cm 3, which is comparable or higher than that of Er 3+-doped tellurite- and germanate-based glasses.