Numerical model of the temperature dependence of the up-conversion efficiency of fluoride crystals codoped with ytterbium and thulium

Abstract

We review the role of temperature on the up-conversion efficiency of materials that are good candidates to be used as the three primary-color emitters in optically written displays. A rate equation model is given for the blue emitting material that includes temperature-dependent coefficients for energy transfer and cross relaxation. Increased temperature leads to decreased up-conversion efficiency. The effect of pumping conditions on heating the emitting material is illustrated and explained. Steps to reduce the temperature rise when pumping up-conversion materials are described