Abstract: An optical chromatic dispersion compensation module consists of a portion of fiber (10) comprising a variable pitch Bragg grating and a mechanical structure (1) consisting of two flexible mountings (2, 2?) and one fixed mounting (3). The portion of fiber (10) is attached to said mechanical structure (1) at three points: A first soft mount point (5) is connected to the fixed mounting (3) and two rigid mount points (4, 4?) are connected to the flexible mountings (2, 2?). The module also consists of a mechanical actuator (20) designed to act on the mechanical structure (1) to compress a first portion of the Bragg grating and to stretch a second portion of the Bragg grating while keeping the central section of the grating fixed. The chromatic dispersion value produced by the Bragg grating filter is thus modified, while its central wavelength remains fixed.

Abstract: An optical amplification system is described which comprises an optical amplifier and an optical filter. The gain of the optical amplifier is changeable to different gain values. For every one of the gain values, a wavelength-dependent gain curve exists. At least for one of the gain values, the gain curve varies over the wavelength. An apodized long-period grating (LPG) is used as the optical filter. The apodized LPG provides at least one wavelength-dependent attenuation curve which compensates the gain curve varying over the wavelength.

Abstract: An optical chromatic dispersion compensation module consists of a portion of fiber (10) comprising a variable pitch Bragg grating and a mechanical structure (1) consisting of two flexible mountings (2, 2?) and one fixed mounting (3). The portion of fiber (10) is attached to said mechanical structure (1) at three points: A first soft mount point (5) is connected to the fixed mounting (3) and two rigid mount points (4, 4?) are connected to the flexible mountings (2, 2?). The module also consists of a mechanical actuator (20) designed to act on the mechanical structure (1) to compress a first portion of the Bragg grating and to stretch a second portion of the Bragg grating while keeping the central section of the grating fixed. The chromatic dispersion value produced by the Bragg grating filter is thus modified, while its central wavelength remains fixed.

Abstract: A tuneable optical fibre comprising a long-period Bragg grating (5) written in a portion of an optical waveguide (10) comprising a core and an optical cladding (11), characterised in that the portion of the waveguide comprising the grating (5) is at least partially immersed in an external environment consisting of two distinct sections, a first section (1) whose refractive index is higher than that of the optical cladding (11) and a second section (2) whose refractive index is lower than that of the optical cladding (11), the long-period grating being at least partially immersed in one of the said sections so as to almost independently tune the wavelength and/or the contrast of the spectral response of the filter.

Abstract: The present invention proposes optical fiber equipment having a Bragg grating tunable by a piezoelectric actuator, the equipment comprising an optical fiber, a Bragg grating photoinduced in said fiber, a support for supporting said fiber and comprising two uprights at opposite ends of said Bragg grating, each upright having a first holding element for holding said fiber, and a piezoelectric actuator held via its ends between the two uprights, said actuator being longitudinally prestressed in compression between said uprights.

Abstract: The present invention relates to a Bragg grating filter optical waveguide device, comprising an optical fiber provided with a Bragg grating region which is externally strained to alter the range of chirping. The external strain is induced by a gradient-generating mechanical body bonded onto the length of the fiber grating.

Abstract: A tuneable optical fibre comprising a long-period Bragg grating (5) written in a portion of an optical waveguide (10) comprising a core and an optical cladding (11), characterised in that the portion of the waveguide comprising the grating (5) is at least partially immersed in an external environment consisting of two distinct sections, a first section (1) whose refractive index is higher than that of the optical cladding (11) and a second section (2) whose refractive index is lower than that of the optical cladding (11), the long-period grating being at least partially immersed in one of the said sections so as to almost independently tune the wavelength and/or the contrast of the spectral response of the filter.

Abstract: A system for compensating chromatic dispersion includes a long variable pitch Bragg grating written in an optical fiber in which wavelength division multiplexed transmission channels propagate. A system for generating a thermal gradient includes at least two heating systems distributed over the grating and controlled independently of each other to compensate simultaneously the chromatic dispersion on a plurality of transmission channels.

Abstract: The present invention proposes optical fiber equipment having a Bragg grating tunable by a piezoelectric actuator, the equipment comprising an optical fiber, a Bragg grating photoinduced in said fiber, a support for supporting said fiber and comprising two uprights at opposite ends of said Bragg grating, each upright having a first holding element for holding said fiber, and a piezoelectric actuator held via its ends between the two uprights, said actuator being longitudinally prestressed in compression between said uprights.

Abstract: The present invention relates to a Bragg grating filter optical waveguide device, comprising an optical fiber provided with a Bragg grating region which is externally strained to alter the range of chirping. The external strain is induced by a gradient-generating mechanical body bonded onto the length of the fiber grating.

Abstract: The present invention relates to a temperature compensating device for a prestrained fiber grating of an optical fiber, wherein said device comprises a body with a substantially cylindrical form and wherein the fiber grating is wound up on said body, whereby the dimensions of said body vary according to a change in temperature. The temperature compensating devive according to the invention is athermal and allows a tunig of the wavelength of the fiber grating.

Abstract: A DFB laser (2) is coupled to a monomode line fiber (14) via an isolator constituted by a Faraday rotator crystal (4) and a polarizing fiber (10) which is welded to a fiber to be coupled (14). A focusing lens (8) is integrated in an intermediate block including the rotator crystal (4) and a permanent magnet (6). The invention is particularly suitable for making light-emitting heads for use in optical fiber telecommunications systems.