A new organic dye, trans-4, 4′-bis(pyrrolidingl) stilbene (BPAS), with large two-photon absorption (TPA) and three-photon absorption (3PA) has been synthesized. The molecular TPA cross section ς<sub>2</sub>′ at 550–670 nm and the 3PA cross section ς<sub>3</sub>′ at 720–1000 nm have been measured. The biggest ς<sub>2</sub>′ and ς<sub>3</sub>′ was 5.77 × 10<sup>−47</sup> cm<sup>4</sup>s/photon and 27 × 10<sup>−75</sup> cm<sup>6</sup> s<sup>2</sup> at 600 and 980 nm, respectively. In the experiment process we found that the strongest TPA wavelength is not at two times of the strongest linear absorption wavelength, but there is some blue shift. The 3PA-induced optical power-limiting properties have also been illustrated at 980 nm.
© 2002 Optical Society of America
Guangyong Zhou, Xiaomei Wang, Dong Wang, Zongshu Shao, and Minhua Jiang, "Upconversion Fluorescence and Optical Power Limiting Effects Based on the Two- and Three-Photon Absorption Process of a New Organic Dye BPAS," Appl. Opt. 41, 1120-1123 (2002)