Tb(3+)/Yb(3+) co-activated Silica-Hafnia glass ceramic waveguides

70SiO(2)-30HfO(2) glass ceramic planar waveguides co-activated by Tb(3+)/Yb(3+) ions were fabricated by sol gel route using a top-down approach. The energy transfer from Tb(3+) to Yb(3+) ions was investigated as a function of the Tb(3+)/Yb(3+) molar ratio as well as of the total amount of rare earth ions. In particular, the conversion of absorbed photons at 476 nm into photons at 980 nm is considered, looking for potential application in photovoltaic systems. (C) 2010 Elsevier B.V. All rights reserved.