Compressional stability of optical fibres: a combined experimental and computer study

Compressional stability is an important mechanical factor that influences the overall performance of a fibre. Assessment of the compressive stability and internal-stress distribution of a fibre must be performed to determine the effect of stress-induced birefringence due to the high deformation gradients in an unstable fibre. The purpose of this study is to combine experimental and finite element investigations of stress evolution and large post-buckling fibre deformations. The results of this study show that stability is greatly influenced by the initial curvature of the fibre. Increasing the deformation of the fibre leads to post-buckling behaviour that results in a fibre taking a complex shape with altered stress-field components. The results are compared with the analytical relation given by Euler's theory of a thin beam and show that the simple analytical formula cannot predict the complicated post-buckling states and stresses.