Fluorescence and gain predictions in laser dye mixtures

Radiative energy transfer in three different laser dye mixtures composed of (1) dichlorofluorescein (donor) and DODC (acceptor), (2) dichlorofluorescein (donor) and RhB (acceptor), and (3) coumarine (donor) and RhB (acceptor) have been studied under steady state excitation conditions. Analytical expressions have been developed to predict steady state fluorescence and hence gain line shape of laser dye mixtures using computer simulation. The theoretical predictions derived are generally in excellent agreement with experimental results, which confirm that at the mixture concentrations needed for lasing, radiative transfer is the dominant energy transfer mechanism. The method developed is effective and practical for predicting laser gain lineshapes (and hence tunability) as well as predicting fluorescence emission spectra of dye mixtures.