Abstract: A buffered optical fiber includes an optical waveguide, at least one exterior coating surrounding the optical waveguide and a buffer coating surrounding the at least one exterior coating, wherein the buffer coating is a tight buffer coating made of a material having a density of at least about 1.2 Kg/dm3, a thermal conductivity of at least about 0.4 W/m·K and includes a polymeric matrix and an inorganic filler.

Abstract: A method of evaluating the Polarization Mode Dispersion (PMD) of an optical fiber by arranging the optical fiber at substantially zero tension on a surface, propagating prescribed evaluation optical signals along the optical fiber, measuring fiber Differential Group Delay (DGD) values in response to the evaluation optical signals, repeating at least once the acts of propagating and measuring, each time preliminarily inducing a change in a mode coupling of the fiber, and determining the fiber PMD on the basis of a calculated DGD average value. Changes in the polarization mode coupling of the fiber are induced by, moving at least a section of the fiber substantially orthogonally to the surface.

Abstract: A buffered optical fibre includes an optical waveguide, at least one exterior coating surrounding the optical waveguide and a buffer coating surrounding the at least one exterior coating, wherein the buffer coating is a tight buffer coating made of a material having a density of at least about 1.2 Kg/dm3, a thermal conductivity of at least about 0.4 W/m·K and includes a polymeric matrix and an inorganic filler.

Abstract: An optical fiber link has a plurality of optical fiber spans joined one to the other, the plurality of optical fiber spans including at least one first unidirectionally-spun optical fiber span and at least one second unidirectionally-spun optical fiber span having mutually opposite spinning directions.

Abstract: The eye is positioned relative to a detection device in such a manner as to co-operate with the device to form a Fabry-Perot cavity having a main optical axis and comprising two opposite reflecting faces on the main optical axis, one of these two faces being constituted by a stationary reflecting element and the other being formed by the cornea of the eye. An incident laser beam is injected into said cavity so as to be centered on the main optical axis of the Fabry-Perot cavity, the cornea is aligned laterally and longitudinally relative to the main optical axis in such a manner as to obtain longitudinal interference between the go and the return laser beams reflected between the two reflecting faces of the cavity, and an optoelectronic detector is used to detect the intensity I of said interference as a function of time. The invention is applicable to measuring intraocular pressure.

Abstract: An apparatus for producing a low-PMD optical fiber having a furnace for melting a lower portion of an optical preform; a traction device for pulling an optical fiber from the lower portion of an optical preform; a spinning device for imparting a substantially constant and unidirectional spin to the optical fiber as it is pulled, which causes the fiber to undergo an elastic torsion; a winding device for winding the optical fiber onto a reel; and a twisting device for imparting to the spun optical fiber a unidirectional twist in a direction opposite the elastic torsion, so as to control the residual twist in the optical fiber. A process for producing the fiber, an optical fiber and a cable are also provided.

Abstract: An optical fiber link has a plurality of optical fiber spans joined one to the other, the plurality of optical fiber spans including at least one first unidirectionally-spun optical fiber span and at least one second unidirectionally-spun optical fiber span having mutually opposite spinning directions.

Abstract: A method of evaluating the Polarization Mode Dispersion (PMD) of an optical fiber by arranging the optical fiber at substantially zero tension on a surface, propagating prescribed evaluation optical signals along the optical fiber, measuring fiber Differential Group Delay (DGD) values in response to the evaluation optical signals, repeating at least once the acts of propagating and measuring, each time preliminarily inducing a change in a mode coupling of the fiber, and determining the fiber PMD on the basis of a calculated DGD average value. Changes in the polarization mode coupling of the fiber are induced by, moving at least a section of the fiber substantially orthogonally to the surface.

Abstract: An apparatus for producing a low-PMD optical fiber having a furnace for melting a lower portion of an optical preform; a traction device for pulling an optical fiber from the lower portion of an optical preform; a spinning device for imparting a substantially constant and unidirectional spin to the optical fiber as it is pulled, which causes the fiber to undergo an elastic torsion; a winding device for winding the optical fiber onto a reel; and a twisting device for imparting to the spun optical fiber a unidirectional twist in a direction opposite the elastic torsion, so as to control the residual twist in the optical fiber. A process for producing the fiber, an optical fiber and a cable are also provided.

Abstract: A pumping module having a cascaded Raman laser for Raman amplified optical transmission systems. Non-linear parametric phenomena, such as Raman-assisted three-wave mixing, in Raman amplified signals from a cascaded Raman pump are strongly reduced by substantially suppressing from the output spectrum of the Raman pump the emission peaks at wavelengths shorter than that of the desired pumping wave on a specific wavelength ?n, and within a given spacing from ?n. The pumping non-zero dispersion fibres have zero dispersion between the wavelength range of the transmission signal and the wavelength range of the pump signal.

Abstract: The eye is positioned relative to a detection device in such a manner as to co-operate with the device to form a Fabry-Perot cavity having a main optical axis and comprising two opposite reflecting faces on the main optical axis, one of these two faces being constituted by a stationary reflecting element and the other being formed by the cornea of the eye. An incident laser beam is injected into said cavity so as to be centered on the main optical axis of the Fabry-Perot cavity, the cornea is aligned laterally and longitudinally relative to the main optical axis in such a manner as to obtain longitudinal interference between the go and the return laser beams reflected between the two reflecting faces of the cavity, and an optoelectronic detector is used to detect the intensity I of said interference as a function of time. The invention is applicable to measuring intraocular pressure.