Special issue paper. Transmission characteristics of W-type optical fibres

Abstract

Properties of doubly-clad optical fibres with a low-index inner cladding (W-type fibres) as single-mode or multimode transmission lines are discussed both from theoretical and experimental viewpoints. Such fibres are characterised by the tight confinement of the modal power in the core. A small bending loss is one of its consequences. A single-mode W-type fibre can be used at a v-value significantly larger than 2.405, and it has an anomalous dispersion effect. A multimode W-type fibre is also discussed.