Evaluation of fluorescence quantum yields using thermal lens Zscan measurements: theoretical and experimental errors for low and high quantum yields

This study applies the single-beam Z-scan thermal lens (TL) technique to assess the fluorescence quantum yield in solutions with high-moderate absorption. The investigation covers two distinct scenarios: solutions exhibiting substantial fluorescence and those characterized by high thermal efficiency but low fluorescence. Analytical calculations are carried out to quantify the uncertainties arising from random errors introduced by optical detectors. The findings highlight that solutions with low fluorescence contribute to significant errors, while higher fluorescence levels aid in reducing uncertainty. Furthermore, a review addresses the challenge of random errors encountered when multiple measurements are required for accurate fluorescence estimation in various situations.