Peak stimulated emission cross sections and quantum efficiencies of Sm3+ and Sm3+-Eu3+ co-doped bismuth boro-tellurite glasses

Abstract

The effect of host glass composition and co-doping with Eu3+ on the optical properties of Sm3+ has been investigated in bismuth boro-tellurite glasses. The intensity parameters Ωt (t = 2,4,6), radiative transition probability (Arad) and radiative lifetimes (τrad) are obtained from optical absorption studies. Excitation spectra show that there exists energy transfer from Sm3+ to Eu3+ and vice versa. From fluorescence studies, fluorescence decay time (τexp), radiative quantum efficiencies (η), branching ratios (β) and peak stimulated emission cross section (σp) are obtained. The highest η of Sm3+ doped bismuth boro-tellurite glasses is found to be 60% and for Sm3+-Eu3+ co-doped glasses, it is 74%. Changing the host glass composition and co-doping with Eu3+ ions, the η of the glasses can be improved. The σp of Sm3+-Eu3+ doped glasses is found to be larger than that of singly doped Sm3+ glasses. Our results indicate that modifying the host glass composition and co-doping with Eu3+ can improve the emission characteristics of Sm3+ ions. Bismuth boro-tellurite glasses with enhanced values for η and σp are suitable for photonic devices and photovoltaic applications.