Two-photon absorption-induced optical properties of a new lasing dye in two solvents

Pumped by an infrared lasing and its frequency-doubling source, the fluores cence and superradiance emission properties of a new lasing dye trans-4-[4' -(N,N-diethylamino)-styryl]-N-methyl pyridinium methyl sulfate (abbreviated DEASPS), have been studied in benzyl alcohol and chloroform. The two-photo n absorption (TPA) and emission properties of DEASPS are influenced by the solvents used. The emission wavelength of the dye in benzyl alcohol is reds hifted relative to that in chloroform. The lifetime of two-photon absorptio n-induced fluorescence is about 529 ps in benzyl alcohol, whereas it is 340 ps in chloroform. Correspondingly, the one-photon-excited fluorescence lif etimes in the two solvents are also given. The upconversion efficiency of D EASPS in chloroform is higher than in benzyl alcohol. Finally, the effectiv e molecular two-photon absorption cross-sections were measured by the nonli near transmittance method. It is found that the optical limiting effect of the dye in benzyl alcohol is stronger than that in chloroform.