The spectroscopic properties of Er3+-doped antimony–borate glasses

The spectroscopic properties of Er3+-doped Sb2O3–B2O3 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 30Sb2O3–69B2O3–1Er2O2 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 4I13/2→4I15/2 transition of Er3+ ions and the measured lifetime of the 4I13/2 level of Er3+ ions are 6.01×10−21 cm2 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 Er3+ in Sb2O3–B2O3 glasses increases with increasing Sb2O3 content. It is noted that the product of the emission cross-section and the FWHM of the glass, σe×FWHM, is as great as 567×10−28 cm3, which is comparable or higher than that of Er3+-doped tellurite- and germanate-based glasses.