Abstract: According to one aspect, the invention relates to a device (200) for transporting and controlling light beams comprising a light guide (40) comprising a bundle (50) of uncoupled single-mode optical fibers (Fi), each single-mode optical fiber (Fi) being intended to receive an elementary light beam (B1i) at a proximal end and to emit a light beam (B2i) at a distal end, said bundle of single-mode optical fibers comprising, in operation, a minimum radius of curvature corresponding to a maximum curvature of the bundle of fibers.

Abstract: According to one aspect, a few-mode amplifying fiber in a given spectral band of use is provided. The few-mode amplifying fiber comprises a cladding having a given refractive index (n0) and at least one core of refractive index and of dimensions suited to the propagation of a finite number of spatial modes in the spectral band of use of the fiber, a spatial propagation mode corresponding to a channel for transporting information. The core comprises a first solid material having a given first refractive index (n1) strictly greater than the refractive index of the cladding (n0), and, within said first material, inclusions spatially separated from one another, formed by longitudinal bars comprising a second solid material having a second refractive index (n2) strictly greater than the first refractive index (n1), at least one of said inclusions being actively doped.

Abstract: According to one aspect, the invention relates to a device (200) for transporting and controlling light beams comprising a light guide (40) comprising a bundle (50) of uncoupled single-mode optical fibers (Fi), each single-mode optical fiber (Fi) being intended to receive an elementary light beam (B1i) at a proximal end and to emit a light beam (B2i) at a distal end, said bundle of single-mode optical fibers comprising, in operation, a minimum radius of curvature corresponding to a maximum curvature of the bundle of fibers.

Abstract: According to one aspect, a few-mode amplifying fiber in a given spectral band of use is provided. The few-mode amplifying fiber comprises a cladding having a given refractive index (n0) and at least one core of refractive index and of dimensions suited to the propagation of a finite number of spatial modes in the spectral band of use of the fiber, a spatial propagation mode corresponding to a channel for transporting information. The core comprises a first solid material having a given first refractive index (n1) strictly greater than the refractive index of the cladding (n0), and, within said first material, inclusions spatially separated from one another, formed by longitudinal bars comprising a second solid material having a second refractive index (n2) strictly greater than the first refractive index (n1), at least one of said inclusions being actively doped.

Abstract: A device for converting transverse spatial profile of intensity of a light beam, using a microstructured optical fiber. Transverse dimensions of the fiber vary longitudinally and both its ends have opto-geometrical parameters such that at the wavelength of the beam the fiber has a fundamental mode having two different profile shapes at its two ends. Thus by introducing the beam with one of the profiles through one of the two ends, the beam emerges through the other end with the other profile, whose shape is different from that of the profile of the introduced beam.

Abstract: The fiber comprises a core (2) having an index N and diameter of 10 ?m or more, surrounded by a ring (4) having an index N+?n and thickness ?R, and cladding (6) surrounding the ring and comprising for example air gaps (8). According to the invention: ?n?10?3 and ?R=?/(?n)? [1] where: 5×10?4 ?m???5×10?2 ?m and 0.5???1.5. The numbers ? and ? are dependent on the wavelength ? of the light guided by the fiber, the number of missing gaps therein, the diameter d of the gaps, the spacing ? thereof and N. To design the fiber, ?, the number of missing gaps, d/?, the core doping content, ? and ?n are chosen; and ?R is determined using equation [1] so as to obtain a flattened fundamental mode.

Abstract: A device for converting transverse spatial profile of intensity of a light beam, using a microstructured optical fiber. Transverse dimensions of the fiber vary longitudinally and both its ends have opto-geometrical parameters such that at the wavelength of the beam the fiber has a fundamental mode having two different profile shapes at its two ends. Thus by introducing the beam with one of the profiles through one of the two ends, the beam emerges through the other end with the other profile, whose shape is different from that of the profile of the introduced beam.

Abstract: The fibre comprises a core (2) having an index N and diameter of 10 ?m or more, surrounded by a ring (4) having an index N+?n and thickness ?R, and cladding (6) surrounding the ring and comprising for example air gaps (8). According to the invention: ?n?10?3 and ?R=?/(?n)? [1] where: 5×10?4 ?m???5×10?2 ?m and 0.5???1.5. The numbers ? and ? are dependent on the wavelength ? of the light guided by the fibre, the number of missing gaps therein, the diameter d of the gaps, the spacing ? thereof and N. To design the fibre, ?, the number of missing gaps, d/?, the core doping content, ?0 and ?n are chosen; and ?R is determined using equation [1] so as to obtain a flattened fundamental mode.

Abstract: The process for the synthesis of a silica monolith comprises the following steps: hydrolysis of a silicon alkoxide in order to form a hydrolysis precursor followed by a condensation of said hydrolysis precursor in the presence of an organic solvent, in the presence of water and of a basic catalyst in order to form oligomeric clusters containing several silicon atoms; dispersion of said oligomeric clusters in a solution in order to form a sol; polymerization of the sol in order to obtain a gel via a first heat treatment, at a temperature below the boiling point of the constituents of the sol; drying of the gel via a second heat treatment; conversion of the gel to a xerogel via a third heat treatment; dehydration and densification of the xerogel until the silica monolith is obtained via a fourth heat treatment.

Abstract: The microstructured optical fibre comprises a core (4) surrounded by a sheath (1) comprising a base material having a refraction index (ni) and a plurality of at least two different types of inclusion: a first type of inclusion (2) having a refraction index n2 (n2>n1), and a second type of inclusion (3) having a refraction index n3 (n3<n1). The inclusions (2, 3) are arranged and dimensioned in such a way as to ensure guidance, by total internal reflection (RTI), of a fundamental mode of the light, centred on a wavelength ?RTI, and of a fundamental mode of the light in the first photonic forbidden band (BG1), centred on a wavelength ?BG1, which is different to that ?RTI of the fundamental mode guided by total internal reflection (RTI).

Abstract: The present invention relates to a process for the synthesis of a silica monolith according to a process known as a “sol-gel process” that comprises the following steps: hydrolysis of a silicon alkoxide in order to form a hydrolysis precursor followed by a condensation of said hydrolysis precursor in the presence of an organic solvent, in the presence of water and of a basic catalyst in order to form oligomeric clusters containing several silicon atoms; dispersion of said oligomeric clusters in a solution in order to form a sol; polymerization of the sol in order to obtain a gel via a first heat treatment, at a temperature below the boiling point of the constituents of the sol; drying of the gel via a second heat treatment including an exposure of the gel to around 90° C. for at least 24 hours followed by an increase in temperature, under vacuum, between around 90° C. and around 180° C., said temperature increase being between 0.1/min and 5° C.

Abstract: The microstructured optical fibre comprises a core (4) surrounded by a sheath (1) comprising a base material having a refraction index (ni) and a plurality of at least two different types of inclusion: a first type of inclusion (2) having a refraction index n2 (n2>n1), and a second type of inclusion (3) having a refraction index n3 (n3<n1). The inclusions (2, 3) are arranged and dimensioned in such a way as to ensure guidance, by total internal reflection (RTI), of a fundamental mode of the light, centred on a wavelength ?RTI, and of a fundamental mode of the light in the first photonic forbidden band (BG1), centred on a wavelength ?BG1, which is different to that ?RTI of the fundamental mode guided by total internal reflection (RTI).