Figure 2

Absorption spectra of Er³⁺ doped germanate glasses.

The inset (a) is the absorption coefficients of Er³⁺ in Y3Er and N3Er samples and the inset (b) is the variation of integral absorption intensities of the ⁴I_15/2→ ⁴I_13/2 transition as a function of Er³⁺ content.