Optical fibre and fibre-optic cable comprising at least one intermetallic element that absorbs hydrogen

In a covering outside its light-guiding portion, an optical fiber includes at least one crystalline intermetallic compound made up of at least two metals, the compound having a plateau pressure during hydride formation that is less than equal to 5x10-2 atm (where 1 atm=1.013x105 Pa) as measured at 30° C. by a PCT method, the compound being of the form ABxMy where A is constituted by at least one element from columns IIa, IIIb, or IVb of the periodic classification of the elements (CAS version), B is constituted by at least one element from columns Vb, VIII, or IIIa of said classification, and M contains at least one element from columns VIb, VIIb, Ib, or IIb of said classification, where:0