Concentration dependence of the gain spectrum in energy-transfer dye mixtures

Abstract
Acceptor concentration dependence of the gain-spectrum peak was measured in coumarin 30 (donor) and rhodamine 6G (acceptor) mixtures. Change of the gain spectrum due to the energy-transfer reaction is attributed to the change of the effective fluorescence lifetime. From the concentration dependence of the effective fluorescence lifetime, rate constants were obtained as follows: kda (for resonance energy transfer) =4×10−11 cm3/sec and k′da (for radiative energy transfer) =2×10−9 cm3/sec. Consequently, the radiative energy transfer was the most dominant mechanism in the energy-transfer reaction.