Structure-property relationships for three-photon absorption in stilbene-based dipolar and quadrupolar chromophores.
Based on essential-state models for three-photon absorption (3PA), we have investigated the structure-property relationships for stilbene-based dipolar and quadrupolar chromophores. The emphasis lies on the evolution of the 3PA cross section with the degree of ground-state polarization. For dipolar systems, we find a dominant role played by Deltamu, which expresses the change in dipole moment between the ground state and the 3PA active excited state. Thus, the strategies usually applied to maximize the second-order polarizability beta are also applicable to optimize the 3PA cross section. For quadrupolar systems, the 3PA response is dominated by contributions from channels including various low-lying two-photon allowed states, which limits the applicability of essential-state models. Optimization strategies can be proposed but vary for different ranges of ground-state polarization.
Zhu
Lingyun
L
Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, 100080 Beijing, People's Republic of China.
Yi
Yuanping
Y
Shuai
Zhigang
Z
Brédas
Jean-Luc
JL
Beljonne
David
D
Zojer
Egbert
E