Chiral Optical Fibre and Grating

The focal purpose of this thesis is to study chirality specifically in telecommunications area, through the pure chiral fibres (optical fibres constituted by chiral material) and chiral fibre grating (twisted optical fibre), analysing also its behaviour and applications. Nevertheless we shall also address this theme from an economical perspective. The study begins by giving a brief introduction of the history behind optical fibre and chiral fibres, followed by an explanation about chirality, using the constitutive relations. While analysing the constitutive relations of the bi-isotropic medium, we will also study the polarization and its rotation. To better understand this chiral medium, we will verify how a plane wave behaved when it focus on the dielectric-chiral medium interface. Then we shall analyse a pure chiral fibre (optical fibre built with chiral material) and with it study the semileaky and surface modes. Afterwards, we will introduce chiral fibre grating, explaining how they are built and their properties. Through these characteristics, we will be able to divide these fibres in three groups: chiral short period gratings, chiral intermediate period grating and chiral long period grating, but also sub-divide each one into two types, double-helix and single-helix. Finally we shall end by analysing the viability of this new technology, not only as the breakthrough innovations that bring telecommunication systems, but also from an economical point of view. KeywordsChirality; Pure chiral fibre; Chiral fibre gratings; Chiral long period gratings; Double-helix; Single-helix.