Thermal lens spectroscopy of Nd:YAG

Abstract

In this work, the thermal lens (TL) spectrometry was performed as a spectroscopic experiment. The spectrum of heat generated by the Nd3+:YAG sample was obtained by continuously tuning a Ti:sapphire laser used as excitation beam. Besides the information about nonradiative efficiency, absolute values of fluorescence quantum efficiency and ds∕dT were determined through the multiwavelength TL method by using six discrete excitation wavelengths (514, 588, 739, 808, 817, and 869 nm). The pumping and fluorescence quantum efficiencies of Nd3+ metastable state (F3∕24) was observed to be constant throughout the range of excitation wavelengths used. For low doping levels (<0.75at.%ofNd3+), the effective quantum efficiency is over 93%.