Ultrafast non-linear optical response and acoustic phonon generation in poly (alkoxy-thiophene) film with regioregular structure
✍ Scribed by M. Nisoli; V. Pruneri; S. De Silvestri; V. Magni; A.M. Gallazzi; C. Romanoni; G. Zerbi; G. Zotti
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 404 KB
- Volume
- 220
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
We investigate by femtosecond pump and probe measurements the non-hnear optical response in thin films of poly(4,4'dipentoxy-2,2'-bithiophene) and poly(4,4"-dipentoxy-2,2': 5',2"-terthiophene), characterized by a high degree of structural regioregularity. These polymers show a fast and high third-order nonlinearity. The effects of removing electrons from the polymer chain in a controlled way by electrochemical doping have also been studied. Finally a periodic modulation of the optical transmission has been observed on an extended time scale, which is related to the propagation of coherent longitudinal acoustic phonons.