Phase-sensitive imaging techniques applied to optical fibre characterisation

Phase-sensitive imaging measurements of optical fibres using quantitative phase microscopy (QPM) are described. In the case of axially symmetric fibres, these measurements can be used to non-destructively determine the refractive-index profiles of single- and multi-mode optical fibres. QPM presents a sensitive, robust, rapid and high spatial resolution technique for reconstructing the refractive-index profile of various fibres and fusion splices. In addition, when used with polarised light, the method is applicable to the investigation of stresses, residual or applied, in single- and multi-mode optical fibres