The microscopic third-order nonlinear-optical susceptibility γ(− ω, ω, ω, − ω) of a conjugated polymer, nonether polyphenylquinoxaline, was observed to be enhanced by two times from 355-nm optically pumped excited-state populations under the condition of unsaturated pumping. We studied the time evolution of the enhancement and verified by a fluorescence measurement that the excited-state enhancement of γ(− ω, ω, ω, − ω) is proportional to the population of the excited state.
© 1995 Optical Society of America
Original Manuscript: July 25, 1994
Published: February 1, 1995
Jun Yan, Meng Sun, Jianyao Wu, Heyuan Zhu, Xiaotian Zhang, Diechi Sun, Yimei Hu, and Fuming Li, "Excited-state enhancement of the third-order nonlinear optical susceptibility of nonether polyphenylquinoxaline," Opt. Lett. 20, 255-257 (1995)