Abstract: The object of the present invention is to design a photonic crystal fiber with high birefringence property such to preserve the polarization of optical signals transmitted through such fiber without implying to high manufacturing cost. For that a photonic crystal fiber is designed having at least the inner rows of the used longitudinal holes surrounding its guiding core following a parallelogram shape arrangement. This leads to a photonic crystal with an at most two fold rotational symmetry about a longitudinal symmetry. It is a particularly advantageous way to introduce a high birefringence which will guarantee to retain the polarisation of the transmitted optical signals.

Abstract: An optical fiber amplifier is considered comprising a mono-mode core, a first cladding around said core and at least a further cladding around said first cladding while said first cladding includes a ring shaped active region doped with rare earth material surrounding said mono-mode core. Advantageously, the first cladding is designed with a radial refractive index following an almost continuous decreasing function for increasing radius. The use of a continuously decreasing refractive index for the cladding at the outer border of the ring shaped active medium optimize the efficiency of the coupling between the core and the cladding.

Abstract: The invention concerns an optical fiber pumped through the cladding, including: a core having an optical index n1, around the core, a first cladding having an index n2 lower than n1, and around the first cladding, a second cladding having an index n3 lower than n2, characterized in that the interface between the first cladding and the second cladding has a substantially polygonal cross section. The invention also concerns a method of fabricating an optical fiber pumped through the cladding, characterized in that it consists in executing the following steps: placing around a central optical preform including a core having an index n1 surrounded by a first cladding having an index n2 lower than n1, a plurality of rods having an index n3 lower than n2, and drawing the optical preform and the rods in a vacuum to obtain an optical fiber including a core and two claddings.

Abstract: An optical fiber with microstructures comprises a plurality of capillary tubes disposed around a central rod and including a self-cleaning layer including molecules able to react with hydroxyl molecules to produce volatile gaseous substances.

Abstract: The present invention concerns an optical guide (100) comprising an amplifier medium including:

Abstract: An optical fiber comprises a silica multimode optical core having a refractive index n1 and at least one polymer optical cladding having a refractive index n2, with n1>n2. It further comprises a heterogeneous polymer intermediate optical cladding situated between the multimode core and the optical cladding and having a refractive index substantially equal to the refractive index n1 of the multimode core.

Abstract: A fiber amplifier comprises an amplifying double-clad fiber (DCF). The fiber has a core having a first refractive index, an inner cladding surrounding the core and having a second refractive index lower than the first refractive index and an outer cladding surrounding the inner cladding. The core is doped with Erbium (Er) and co-doped with Ytterbium (Yb), and further co-doped with Cerium (Ce). The Ytterbium (Yb) enables pump energy transfer from Ytterbium (Yb) ions being in the excited state to Erbium (Er) ions being in the ground state (4I15/2). The Cerium enables a resonant energy transfer between the Erbium (Er) excited state (4I11/2) and Cerium (Ce) ground state (4F7/2). This leads to a lower population of the Erbium 4I11/2 state and thereby increases energy transfer from Ytterbium to Erbium.

Abstract: The invention concerns an optical fiber pumped through the cladding, including:

Abstract: The invention relates to an optical fiber amplifier (OFA) having a controllable heating system for adjusting and stabilizing the temperature of a fiber, wherein the heating system comprises a heat-generating fiber coating (TC) that has an electrical connection for applying a heating voltage or injecting a heating current (I1, I2) for the purpose of heat generation, wherein the heat-generating fiber coating (TC) surrounds at least a part of the fiber (OF), and also a method therefor.

Abstract: A C-band optical amplifier includes a fiber with a monomode core, a multimode internal cladding and an external cladding. It further includes a pump for pumping the fiber. The fiber is not doped with ytterbium and the multimode cladding has a diameter less than 55 &mgr;m. The amplifier can be used for amplifying C-band signals in wavelength division multiplex transmission systems.

Abstract: The invention relates to an optical fiber having a core based on silica with at least one fluorescent dopant distributed over the entire section of the core, a central zone co-doped with a co-dopant chosen from Al and P, and a peripheral zone co-doped with the other co-dopant chosen from Al and P. The invention can be used in an optical fiber amplifier, and it guarantees good amplifier gain flatness over a wavelength band suitable for WDM transmission.

Abstract: A device for doping silica powder with a dopant includes an arrangement for receiving silica soot particles or previously fabricated silica granules. The particles or granules contained in the receiving arrangement are heated to a temperature sufficient to allow agglomeration of the soot particles into granules followed by densification of the granules. The receiving arrangement is fed with a precursor gas of the dopant so that the granules are heated in an atmosphere containing the precursor gas, which causes the dopant to be incorporated into the granules during their densification to produce densified and doped silica grains. The receiving arrangement is mobile so that, during their movement, each of the granules that it contains is subject to movement such that substantially all of its outside surface is exposed to the atmosphere containing the precursor gas.