EFFECT OF THE ULTRASHORT PULSE POLARIZATION ON THE TWO-PHOTON ABSORPTION OF ORGANIC COMPOUNDS

Abstract

Only recently polarization effects in two-photon absorption process have been experimentally investigated in organic and inorganic compounds. Besides the possibility of assisting the investigation of molecular structures, there is also the possibility of exploiting new effects, such as magnetic dipole and electric quadrupole, as well as the parity of electronic states. In this sense, the characterization of the properties and electronic structure of chiral or non-chiral compounds may be performed in combination with standard procedures, such as linear dichroism and optical anisotropy.In this context, this project aims to implement, in a wide spectral range, the techniques of Z-scan, fluorescence excited by two-photon absorption and pump-probe with polarization control. After the implementation of such techniques, they will be used to characterize and quantify the nonlinear effects in organic materials. In a second stage of the project, we intend to use such techniques to observe effects of nonlinear circular dichroism in chiral molecules. In addition, this project will provide additional information that cannot be obtained through conventional techniques in nonlinear optics, especially in compounds that exhibit optical activity. Therefore, we believe that this project will contribute to the development of new insights on nonlinear optical interactions.