Investigation on broadband near-infrared emission and energy transfer in Er3+-Tm3+ codoped germanate glasses

Broadband near-infrared emission has been investigated in a new type host composition of Er3+-Tm3+ codoped germanate glass. A broadband emission extend from 1350 to 1675 nm with the full width at half maximum (FWHM) around 138 nm is obtained in the germanate glass which codoped with 0.2 wt.% Er2O3 and 0.8 wt.% Tm2O3. The energy transfer between Er3+ and Tm3+ plays an important role in the emission mechanism, which is evidenced by the visible upconversion and the lifetime of Er3+:4I13/2 level effected by the addition of Tm2O3. And energy transfer efficiency from Er3+ to Tm3+ reaches 76% for the highest Tm3+ concentration of 0.8 wt.%. These results suggest that this glass would be a promising material for broadband light source and broadband amplifier for the wavelength division multiplexing transmission systems.