Energy transfer between Er3+ and Pr3+ in chalcogenide glasses for dual-wavelength fiber-optic amplifiers

Abstract

Ge–As–Ga–S glasses codoped with ${\mathrm{Er}}^{\text{3+}}$ and ${\mathrm{Pr}}^{\text{3+}}$ were synthesized for fiber-optic amplifiers operating in both 1.3 and 1.5 μm communication windows. The energy transfer between ${\mathrm{Er}}^{\text{3+}}$ and ${\mathrm{Pr}}^{\text{3+}}$ in Ge–As–Ga–S glasses was analyzed quantitatively using rate equations. The energy transfer coefficients responsible for two different energy transfer routes were ${\text{2.2(±0.05)×10}}^{\text{−18}}$ $({\mathrm{Er}}^{\text{3+}}{:}^4{I}_{\text{11/2}}\to {\mathrm{Pr}}^{\text{3+}}{:}^1{G}_4)$ and ${\text{5.6(±0.05)×10}}^{\text{−17}}\hspace{0.17em}{\mathrm{s}}^{\text{−1}} {\mathrm{cm}}^3$ $({\mathrm{Er}}^{\text{3+}}{:}^4{I}_{\text{13/2}}\to {\mathrm{Pr}}^{\text{3+}}{:}^3{F}_{\text{4,3}}\mathrm{),}$ respectively. The former transfer process enhanced amplification efficiency in 1.3 μm band, while the latter reduced efficiency in the 1.5 μm band. Numerical simulation of the amplification characteristics demonstrated that signal gains of 30 and 40 dB were possible in 1.3 and 1.5 μm bands, respectively.