Unexpected optical behaviour of standard single mode fibre cladding

The propagation property of an optical signal along the cladding of a fibre leads to new applications either in the telecommunication or in the sensor fields. In order to analyse the optical behaviour of the cladding, in this contribution, photoelastic measures are presented, realized by means an experimental tomographic set-up useful to measure fibre birefringence. Birefringence depends especially on the frozen internal stress that is generated during the drawing process. Photoelastic tomography is an appropriate method in measuring the stress distribution over an optical fibre section.