Field-enhanced nonlinear optical properties of organic nanofibers

Second harmonic generation in nonlinearly optically active organic nanofibers, generated via self-assembled surface growth from nonsymmetrically functionalized para-quarterphenylene (CNHP4) molecules, has been investigated. After the growth on mica templates, nanofibers have been transferred onto lithographically defined regular arrays of metal and dielectric nanostructures. Such hybrid systems were employed to correlate the second harmonic response to both morphology of the fibers i.e. local field enhancement due to local changes in the fiber's morphology and field enhancement effects appearing on the nanostructures. With the help of femtosecond laser scanning microscopy two-dimensional second-harmonic images of individual nanoaggregates were obtained and analyzed.