Details

Autor(en) / Beteiligte

• Wang, Yaochuan
• Yan, Yongli
• Liu, Dajun
• Wang, Guiqiu
• Pu, Shouzhi

Titel

Photochromism induced nonlinear optical absorption enhancement and ultrafast responses of several dithienylethene compounds

Ist Teil von

• Journal of applied physics, 2015-11, Vol.118 (18)

Ort / Verlag

Melville: American Institute of Physics

Erscheinungsjahr

2015

Quelle

AIP Journals

Beschreibungen/Notizen

• The nonlinear optical properties and ultrafast dynamics of three dithienylethene photochromic derivatives (i.e., P1, P2, and P3) were investigated by two-photon fluorescence, open-aperture Z-scan, and femtosecond pump-probe experiments. Photoinduced ring-closure and ring-opening phenomena, as well as a photochromism induced nonlinear optical property enhancement, were observed. For both the ring-opening and ring-closure state, the curve exhibited an ultrafast absorption peak approximately 200 fs followed by a fast decay process (i.e., ∼1 ps) and a long decay process that had a duration longer than 5 ps. The ultrafast peak followed by a fast decay process and the long decay process were attributable to a special two-photon absorption process, the formation of a charge separation state, and the relaxation of the charge separation state, respectively. However, the magnitude of the signal under the ring-closure state is approximately fivefold greater than that of the ring-opening state, which is in good agreement with nonlinear optical results. Intramolecular charge transfer processes were observed in the dynamics curves of the P2′ and P3′ isomers with D-π-A and D-π-D structures.