Thermal conductivity determination of erbium-doped crystals measured by spatially resolved confocal luminescence

Thermal conductivity of Er³⁺-doped yttrium aluminum perovskite has been obtained by the use of laser induced temperature distribution and time-independent heat propagation equations. By using the spatially resolved microluminescence technique, the fluorescence spectra on the sample surface were mapped during the laser focused heating process, and the local temperature was measured at different spots on the sample surface with micrometric resolution. Significant information about the temperature profile was obtained following the maximum temperature of the laser spot and the behavior of the heat diffusion on the surface of the irradiation side. These data were finally used to feed the heat propagation equations from where the thermal conductivity was evaluated.