Quadratic and cubic nonlinear-optical response of organic microstructures

Optical and nonlinear-optical properties of microstructures of different shapes (hemispheres, frustums and rods) self-assembled from organic dye of high nonlinear susceptibilities are studied. We demonstrate an enhancement of cubic self-action effects in the microstructures in comparison to these effects in corresponding continuous films, which is attributed to the whispering gallery modes excitation. The spectra of these modes and the field distribution within the microstructures are simulated by means of FDTD methods. The field localization data obtained from calculations correspond to the two-photon microscopy images of the structures.