Nanofibers for linear and nonlinear photonics

In this work we exploit growth as well as linear and nonlinear optical properties of long, parallel single-crystalline hexaphenylene (p-6P) nanofibers grown on mica surfaces.: Typical widths and heights of these needle-like structures are a few 10 - 400 nanometers, whereas lengths of up to one millimeter can be achieved. The nanofibers allow us to perform experiments at either densely packed, well-aligned bunches of aggregates or at isolated entities. Linear optical properties are probed by local spectroscopy using a fiber-optic spectrometer and by guiding UV-light through individual fibres and relating the waveguiding efficiency to their morphology using atomic force and fluorescence microscopy. Results are compared with an analytical theory. As nonlinear optical probes we use two-photon luminescence as well as optical second harmonic generation induced by ultrashort laserpulses in the near-infrared spectral range.