A novel organic chromophore (A1) is designed and synthesized with a fine structure for two-photon absorption (TPA). The single-photon induced fluorescence spectra and the fluorescence lifetime have been studied for A1, excited respectively by 297-, 355-, 422-nm laser. And the two-photon induced fluorescence spectra were surveyed when A1 was excited by 820- and 910-nm laser. The results show that the curves of up-converted fluorescence spectra are almost same and have the same peak value at 518 nm. Accordingly, we can draw a conclusion that the TPA occurs when A1 is excited by 820- and 910-nm laser separately and though the absorption-transition pathway is different, the transition-emission pathway is the same.
© 2005 Chinese Optics LettersPDF Article