Electronic and nuclear contributions to the third-order optical susceptibility of the C60-TTF dyads

✍ Scribed by I. Fuks-Janczarek; B. Sahraoui; I.V. Kityk; J. Berdowski

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 263 KB
• Volume: 236
• Category: Article
• ISSN: 0030-4018
• DOI: 10.1016/j.optcom.2004.03.022

✦ Synopsis

We have measured the third-order susceptibility v h3i ijkl of a C 60 -TTF compounds in tetrahydrofuran (THF) solutions using the degenerate four wave mixing technique at k ¼ 532 nm in the picosecond regime. To know the physical nature of the optical non-linearities, we separate the electronic and nuclear contributions in v h3i . From these measurements we have deduced the values of the second-order hyperpolarisabilities c. For the calculation of the susceptibility values, CS 2 has been used a reference material (having v h3i ¼ 1:24 Â 10 À20 m 2 V À2 ) in a standard commonly used procedure taking into account the linear absorption of the sample. As the absorption of the studied compounds is very weak at k ¼ 532. This paper presents a theoretical analysis of the second-order hyperpolarisabilities c t of fullerenes modified, too. Theoretical calculations of the c were carried out at the restricted Hartree-Fock level (RHF) using AM1 and PM3 semiempirical SCF-MO methods within the HyperChem 7.0 program.