Non linear optics of organic molecules and polymers

The search of materials for non-linear optical applications requires the characterization of non-linear chromophores and the deep study of the molecular structure-non-linearity relation-ships. In this field, one of the most interesting bulk organic materials are polymers with non-linear moieties. The study of their non-linear response as a function of the composition and processing conditions is one of our research lines.

We can measure the second order non-linear coefficients of molecules by using the EFISH technique. The excitation wavelength range covers the IR up to 2 microns (Q- switched Nd:YAG laser + frequency doubler + dye laser + H₂ Raman cell).

In the case of chromophores containing polymers, the non-linear macroscopic response can be measured during and after the poling processes (electric Corona and photo-assisted poling) and the non-linear coefficients can be obtained.