title: Large optical nonlinearities of new organophosphorus fullerene derivatives.
abstract: Optical nonlinearities of five new organophosphorus fullerene derivatives with similar structures were determined by the Z-scan method by use of a nanosecond-pulse laser at 532 nm. The experimental results demonstrate that the five derivatives have much larger excited-state absorption and nonlinear refraction than C60. The excited-state absorption cross sections are nearly two to three times that of C60. Using a five-level model to fit the experimental data, we obtained some parameters such as excited-state absorption and refraction cross sections. A simple analysis of correlations between molecular structure and nonlinear properties is given. Optical nonlinearities of the five new organophosphorus fullerene derivatives were compared with those of some other kinds of fullerene derivatives, and the results show that the nonlinearities of the new derivatives are the larger.
authors.affiliation: Photonics Center, College of Physics, Nankai University, Tianjin 300071, China.
authors.forename: Zhi-Bo
authors.initials: ZB
authors.lastname: Liu
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Tian
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Zang
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Zhou
authors.forename: Chun-Ping
authors.initials: CP
authors.lastname: Zhang
authors.forename: Jian-Yu
authors.initials: JY
authors.lastname: Zheng
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Zhou
authors.forename: Hua
authors.initials: H
authors.lastname: Xu