Non-resonant third-order optical non-linearity of porphyrin derivatives

Non-resonant second molecular hyperpolarisabilities (gamma) of tetraphenylporphyrin (H(2)tpp) and five substituted derivatives are measured by the Z-scan technique at 784 nm; the relationship between the various structures and their corresponding molecular hyperpolarisabilities is explained on the basis of electronic interaction between the external substituents and the porphyrin core