The Influence of Torsion on Transmission Function Asymetric Twin Core Fibre

The transmission function of twin core fibre is determined by his fibre length and coupling length if only one of its cores is excited. For design of attenuation components or sensors it is useful known transmission dependence twin core fibres on coupling length variations, because the coupling length depends on difference of effective propagation phase constants appertaining to particular fibre cores. It is possible to change tham by such deformation, which influences the difference of effective phase constants. For this purpose twin core fibres with one core in the centre of fibre are applicable. The simple deformation of fibre in torsion changes the length (and also effective propagation phase constant) of core located out of centre of fibre. The measuring dependencies of the influence of torsion on transmission functions for different values of twist make possible ease interpretation. Their agreement (or disagreement) with description following from theory may be possible indication of eventual misalignment of cores what is important for design of attenuation components with control attenuation or sensors.