NIR to Blue light upconversion in Tm~(3+)/Yb~(3+) codoped BaTiO_3 tellurite glass

摘要

Upconversion is an interesting optical property, generally shown by rare-earth doped materials. This unusual optical behavior shown by these rare-earths doped materials are due to their peculiar atomic configuration and electronic transitions. Here, the Tm~(3+)-Yb~(3+) codoped BaTiO_3 glass with TeO_2 as former has been prepared by conventional melt and quench technique and the upconversion property has been investigated with the help of near infrared (NIR) to Visible UC study. The generation of the visible UC bands around ～ 476 nm, ～ 653 nm, ～702 nm and one NIR UC band at ～795 nm are assigned due to the ~1G_4→~3H_6, ~1G_4→~3F_4, ~3F_2→~3H_6 and ~3H_4→~3H_6 transitions respectively. The generations of these upconversion bands have been discussed in detail with the help of energy level diagram. The colour coordinates corresponding to the prepared material have been shown with the help of CIE chromaticity diagram. These glasses can be very appropriately used in the fabrication of solid state laser and as NIR to blue light upconverter.