Multiwavelength thermal lens determination of fluorescence quantum efficiency of solids:: Application to Nd3+-doped fluoride glass

A multiwavelength thermal lens (TL) method was developed to determine the fluorescence quantum efficiency of solids. The experiments have been performed in Nd3+-doped fluoride glasses, using five different excitation wavelengths: 514, 576, 741, 796, and 867 nm. In this work, the absolute value of fluorescence quantum efficiency can be obtained by the linear dependence of the TL signal with the excitation wavelength. Our results suggest that the method can be applied to study a wide range of fluorescent materials, with a special ability to be used for measurements of highly transparent materials with very low TL effect. (C) 2001 American Institute of Physics.