Multiple rare earth emissions in a multicore tellurite fiber with a single pump wavelength.

A three-core tellurite glass fiber having different combinations of rare earth oxide dopants in each core has been fabricated using shaped die-extrusion. Three cores, doped with Ho3+-Tm3+-Yb3+, Er3+-Ce3+, and Tm3+-Yb3+ respectively, exhibited visible upconversion (blue, green and red) and infrared emissions at 1.4 µm, 1.5 µm, 1.9 µm and 2.05 µm when pumped at a wavelength of 980 nm. The prospects for multi-band amplifiers and lasers are discussed.