Enhancement of upconversion intensity in Er3+ doped tellurite glass in presence of Yb3+
ABSTRACT TeO2–PbO glasses doped/codoped with Er3+/Er3+-Yb3+ ions have been fabricated by melting and quenching method. Efficient frequency upconversion emissions spanning from blue
to red regions corresponding to the 2H11/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions, respectively, upon excitation with 976 nm diode laser radiation have been observed. The variations observed
in the intensity of whole upconversion emission spectra due to the presence of the Yb3+ ions are reported and discussed in detail.