초록 ▼

A method of providing a preform for a polarization-maintaining optical fiber, starting from a basic preform (1) having two orthogonal planes of symmetry intersecting along its axis, and mechanically applying two discrete preformed oblong elements (15) of silica doped with boron oxide on the outside

A method of providing a preform for a polarization-maintaining optical fiber, starting from a basic preform (1) having two orthogonal planes of symmetry intersecting along its axis, and mechanically applying two discrete preformed oblong elements (15) of silica doped with boron oxide on the outside face of said basic preform symmetrically about the first plane (20), and two oblong elements of silica doped with titanium oxide on the outside face of said basic preform and symmetrically about the second plane (30). The shapes of the basic preform and the four oblong elements are selected to define a substantially solid cylinder.

대표청구항 ▼

A method of assembling a preform for a polarization-maintaining optical fiber, comprising the steps of providing a basic monomode preform comprising a solid elongated silica core of circular cross section surrounded by a solid silica cladding, said basic preform having a longitudinal axis intersecte

A method of assembling a preform for a polarization-maintaining optical fiber, comprising the steps of providing a basic monomode preform comprising a solid elongated silica core of circular cross section surrounded by a solid silica cladding, said basic preform having a longitudinal axis intersected by two orthogonal planes of symmetry, attaching on the outside face of said basic preform a first pair of discrete preformed elongated stress elements each consisting essentially of silica doped with boron oxide, said first pair of elongated stress elements being disposed symmetrically about one of said planes and parallel to said axis, attaching on the outside face of said basic preform a second pair of discrete preformed elongated stress elements each consisting essentially of silica doped with titanium oxide said second pair of elongated stress elements being disposed symmetrically about the other of said planes and parallel to said axis, wherein said basic preform, said first pair of elongated stress elements, and said second pair of elongated stress elements complement one another in cross section so as to form a substantially solid cylinder of circular cross section, consisting of the basic preform and two pairs of elongated stress elements, when the two pairs of elongated stress elements are attached to the basic preform.