Abstract: Disclosed is a structure at least partially comprising a composite material, the material being made by means of sheets of fibers embedded in a matrix, the different sheets forming plies of the material, the material comprising intrinsic means for the detection and localization of a mechanical irregularity, these means comprising at least one polarization-maintaining birefrigent optical fiber having a so-called slow axis and a so-called fast axis, embedded in the matrix and describing a known path inside the material, wherein the optical fiber is included inside a casing with an internal diameter that is greater than the external diameter of the fiber.

Abstract: A structure which includes a composite material formed of a plurality sheets forming plies. A casing is formed between two of the plurality of sheets forming the composite material, the casing having an internal diameter. Further, an optical fiber is located within the casing and has an external diameter which is less than the internal diameter of the casing, the optical fiber also having a slow axis and a fast axis of propagation.