Infrared and visible fluorescence in Er³⁺-doped gallium tellurite glasses

Er³⁺-doped gallium tellurite glasses have been fabricated and characterized. Efficient green and red upconversion luminescence, and strong infrared fluorescence at 1.53 μm wavelength were observed under the excitation of a 975 nm diode laser at room temperature. The visible upconversion emission bands centered at 524, 546 and 669 nm have been confirmed that two photons contribute to the upconversion processes. The emission peak locates at 1.53 μm with a full-width at half-maximum of ∼58 nm, and the calculated peak emission cross-section is 8.54 × 10^-21 cm². These values are larger than those in silicate and phosphate glasses. Efficient visible upconversion and infrared luminescence indicate that Er³⁺-doped gallium tellurite glass is a promising laser and amplifier materials.