PROPAGATION DE LA LUMIÈRE DANS LES NANOSTRUCTURES ET CRISTAUX PHOTONIQUES PLANAIRES ASSOCIÉS AUX GUIDES D'ONDE : FABRICATION ET CARACTÉRISATION.

摘要

Nanostructures and particularly photonic crystals give us new opportunities for guided optics : submicronic scale waveguides, 90 degrees bends, resonant cavities, fiber. Combined to traditional optical waveguides, they should permit a higher integration of numerous functions on the component : evanescent addressing modes, spectral filter, signal processing, sensors... Nevertheless, the fabrication of such structures remains a challenge because of accurate requirement concerning the perfect homogeneity and the nanometer scale etching that is needed. In this thesis, after the different parameters have been determined by a band solver and FDTD calculations, two methods based on Focused Ion Beam (FIB) are proposed to fabricate nanostructures combined with waveguides. In a first method, nanostructures are directly etched by FIB milling and in a second one we combine FIB milling and RIE. The structures are fabricated on a substrate where the waveguides are previously deposited. These methods of fabrication have been validated for a multilayer structure (SiO2/SiON/SiO2) deposited on Si substrate. Partial results gave been determined for Lithium Niobate, on which the usual nanostructuring methods are less efficient. Finally we have developed a near-field microscope (SNOM) to characterize the nanostructures. This method is imposed by the high confinement of light in the structures.