Emission characteristics of Ge-Ga-S glasses doped with Tm3+/Ho3+

Abstract

Ge25Ga5S70(at.%) glasses doped with Tm3+ and Ho3+ were prepared and their emission characteristics were evaluated with an emphasis on the 2.02 mu m fluorescence from Ho3+:(I7I)-I-5-I-5-->(8) transition. With constant Ho3+ concentration, intensities of 2.02 mu m emission through the excitation of Tm3+ at 798 nm increased with Tm3+ content which indicates efficient energy transfer from Tm3+ to Ho3+. Rates of energy transfer also increased with Ho3+ concentration but competed against the upconversion phenomenon both in Tm3+ and Ho3+.