Near-IR emission in Pr super(3+)single doped and tunable near-IR emission in Pr super(3+)/Yb super(3+) codoped tellurite tungstate glasses for broadband optical amplifiers

A study of the broadband near-infrared emission in Pr super(3+) single doped and Pr super(3+)/Yb super(3+) codoped tellurite-tungstate glasses for optical amplification is presented. In the Pr super(3+) single doped samples pumped at 474 nm the emission band at 1480 nm presents a FWHM of similar to 140 nm. The Yb super(3+) addition produces a FWHM broadening up to similar to 155 nm, achieved through the super(1)G sub(4)- super(3)H sub(5) transition. The emission spectra when the codoped sample is pumped at 980 nm shows efficient energy transfer from Yb super(3+) to Pr super(3+), resulting in an intense Pr super(3+) emission around 1330 nm. This shows that changing the pump wavelength it is possible to select the super(1)D sub(2)- super(1)G sub(4) or the super(1)G sub(4)- super(3)H sub(5) transition, displacing the emission band from similar to 1480 to similar to 1330 nm.