Lifetime and anisotropy decay of excited Coumarin 30 measured by a femtosecond pump-probe technique

摘要

We measured the lifetime of Coumarin 30 dye molecules excited with 400 nm in ethanol solution with the pump-probe stimulated emission fluorescence technique using femtosecond laser pulses that provided high temporal resolution of about 50 fs. Both fluorescence and stimulated emission signals were observed. The stimulated emission was induced at 550 nm. The lifetime of the excited state was determined to be (1.9 +/- 0.3) ns and the rotational depolarization time was measured to be (120 +/- 20) ps. Our results are in agreement with data obtained previously by a different technique.