Photophysics of TICT states of 7-diethylamino-4-methyl coumarin dye by energy transfer techniques.

Coumarin 1 exhibited dual amplified spontaneous emission (ASE) in certain solvents under nitrogen laser excitation. These emissions are known as normal and anomalous emissions. The anomalous emission corresponds to TICT state and it does not have a corresponding fluorescence peak. Energy transfer techniques have been used to study the photophysics of TICT states and the characteristics of dual ASE bands of the dye coumarin 1.