Third-order Nonlinear Optical Properties in New Thiophene-based Extended p-conjugated Systems
I. Fuks-Janczarek, A. Migalska-Zalas, S. Dabos-Seignon, B. Sahraui, T.J. Zoueu, I.V. Kityk, J. Roncali and C. Martineau
We report measurements of the third-order susceptibilities and twophoton absorption in new C3h thiophene-based conjugated systems C66H96S3, C60H90S3, using degenerate four wave mixing (DFWM) technique at l = 532 nm in the picosecond regime. We have found that increasing number of p-conjugated double bonds leads to an increase of c<3>. The obtained non linear third-order properties are very large compared to CS2 which is a reference material for such studies . We show also an increase of the figure of merit with extension of p-conjugation. The obtained result indicates that these novel compounds are promising for photonic applications. In particular due to their important two-photon absorption coefficients these materials could be useful for optical limiting application.