Low-temperature homogeneous linewidths ofYb3+in inorganic glasses

Abstract

We have measured the homogeneous linewidth of the ${}_{}{}^2{}_{}{}^{}\mathrm{F}_{5/2}^{}{}_{}{}^{}$(1)${\mathrm{-}}^2$ ${\mathrm{F}}_{7/2}$(1) transition of ${\mathrm{Yb}}^{3+}$ in silicate and phosphate glasses using fluorescence line narrowing between 6.5 and 70 K. The linewidth is observed to vary as $T^{1.9\pm 0.1}$ at high temperature, changing to $T^{1.3\pm 0.1}$ below 40 K. This behavior is compared to that observed in other systems and examined in light of current theories of dephasing in disordered systems.