Applications of rare-earth ion doped crystals for temperature measurement

摘要

Excited rare-earth ions relax radiatively and non-radiatively. The non-radiative relaxation rate and hence the lifetime of the excited level exhibit temperature dependence. These materials can be used to sense temperature below the melting point of the crystal. We have developed calibration standards using rare-earth ion doped crystals. The sensitivity of the technique and the applicable temperature range depends on the ionic energy levels and the type of crystal. We will discuss some of the results obtained in rare-earth ion doped fluoride and oxide crystals.