Abstract: An electromagnetic waveguide, such as an optical fibre, including a hollow central core surrounded by a microstructured sheath formed by an assembly of elementary cells, the microstructured sheath also including at least two elementary cells, at least one intermediate element connecting the elementary cells, the intermediate element having a cross-section with an area less than or equal to 50% of the cross-sectional area of each of the cells that it connects, the intermediate element having a refractive index less than or equal to the refractive index of each of the elementary cells that it connects.

Abstract: A method for manufacturing an optical fibre, in which a preform is inserted into a furnace; the preform is drawn via an outlet of the furnace; and the drawn preform has a working area including a structure composed of walls, and gas streams are applied to the two opposite faces of these walls, which streams run along the walls in opposite directions, so as to subject the walls to a shear force of gas streams counter-propagating on either side of the walls. A device for manufacturing an optical fibre is also provided.

Abstract: A waveguide with a hollow core (16) delimited by a closed contour includes a succession of arcs (20) of negative curvature, each arc including a chord (24), characterized in that the contour of the hollow core (16) includes small arcs (PA) and large arcs (GA) arranged alternately, each arc (20) being symmetric with respect to a straight line passing through the center (18) of the hollow core (16) and the middle of the chord (24) thereof, the ratio b=2Ra/C of the large arcs being greater than 0.9 for the large arcs (GA), Ra corresponding to the maximum distance between the chord (24) and the arc (20), C corresponding to the length of the chord (24).

Abstract: A waveguide with a hollow core (16) delimited by a closed contour includes a succession of arcs (20) of negative curvature, each arc including a chord (24), characterized in that the contour of the hollow core (16) includes small arcs (PA) and large arcs (GA) arranged alternately, each arc (20) being symmetric with respect to a straight line passing through the centre (18) of the hollow core (16) and the middle of the chord (24) thereof, the ratio b=2Ra/C of the large arcs being greater than 0.9 for the large arcs (GA), Ra corresponding to the maximum distance between the chord (24) and the arc (20), C corresponding to the length of the chord (24).

Abstract: A device for the excitation of a gas medium (10) contained in a casing (12), the device being coupled to the casing (12) and disposed outside same and including an applicator that can generate lateral excitation inside the casing (12) over at least a portion thereof. The device is characterized in that the casing (12) is a hollow-core photonic dielectric structure (16), in which the core has a diameter smaller than 300 ?m, and in that the applicator is of the microwave type and can be used to generate a surface wave that can create and confine a microplasma from the gaseous medium contained in the casing (12).

Abstract: A device for the excitation of a gas medium (10) contained in a casing (12), the device being coupled to the casing (12) and disposed outside same and including an applicator that can generate lateral excitation inside the casing (12) over at least a portion thereof. The device is characterized in that the casing (12) is a hollow-core photonic dielectric structure (16), in which the core has a diameter smaller than 300 ?m, and in that the applicator is of the microwave type and can be used to generate a surface wave that can create and confine a micro-plasma from the gaseous medium contained in the casing (12).

Abstract: A device is provided that includes an optical fiber and an assembly illuminating the optical fiber capable of illuminating the optical fiber at an upstream end. The optical fiber includes a hollow core and an anti-resonant annular cladding arranged around the hollow core. The illuminating assembly generates a focused beam of Airy spot shape for injection into the input of the optical fiber.

Abstract: An optical module for chromatic dispersion compensation comprises an optical fiber wound so as to present a variable radius of curvature. The fiber has an index profile such that it has, for the main propagation mode, a negative dispersion value having a minimum at a given wavelength in a given spectral band. The value and the spectral position of the dispersion minimum vary with the radius of curvature of the fiber. The module allows the introduction of a large chromatic dispersion compensation value overall of a given spectral band, as well as compensation corrections for specific wavelengths inside the given spectral band.

Abstract: An optical module for chromatic dispersion compensation comprises an optical fiber wound so as to present a variable radius of curvature. The fiber has an index profile such that it has, for the main propagation mode, a negative dispersion value having a minimum at a given wavelength in a given spectral band. The value and the spectral position of the dispersion minimum vary with the radius of curvature of the fiber. The module allows the introduction of a large chromatic dispersion compensation value overall of a given spectral band, as well as compensation corrections for specific wavelengths inside the given spectral band.