Excited-state enhancement of the third-order nonlinear optical susceptibility of nonether polyphenylquinoxaline.
The microscopic third-order nonlinear-optical susceptibility gamma(-omega; omega, omega, -omega) 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 gamma(-omega; omega, omega, -omega) is proportional to the population of the excited state.
J
J
Yan
J
J
Wu
H
H
Zhu
X
X
Zhang
D
D
Sun
Y
Y
Hu
F
F
Li
M
M
Sun