Determination of spectral linewidths by Voigt profiles inYb3+-doped fluorozirconate glasses

Abstract

Homogeneous and inhomogeneous spectral linewidths of the ${(}^2{F}_{5/2}{)}_1-{(}^2{F}_{7/2}{)}_1$ transition in ${\mathrm{Yb}}^{3+}$-doped fluorozirconate glasses are determined by fitting Voigt profiles to the inhomogeneously broadened emission and absorption spectra between 10 and 300 K. The homogeneous linewidth varied as $(12\mathrm{}\pm 2)\times T^{(1.9\mathrm{}\pm 0.1)}\mathrm{MHz}$ for emission and $(10\mathrm{}\pm 1)\times T^{1.9\pm 0.1}$ for absorption over the entire temperature range, similar to that of other rare-earth-doped systems previously studied by fluorescence line narrowing and photon echoes. The inhomogeneous linewidths were nearly independent of temperature, but different by $\sim 30\%$ between emission and absorption. The structural and dynamic properties in this disordered system are discussed.