Abstract: An optical parametric amplification device, including: an emitter emitting non-monochromatic light pulses as a pump wave; a stretcher configured to receive as an input pump wave, and to output a stretched pump wave; and a waveguide configured to receive as an input the stretched pump wave and chirped pulses, and to provide a wave resulting from a four wave mixing.

Abstract: An optical parametric amplification device, including: an emitter emitting non-monochromatic light pulses as a pump wave; a stretcher configured to receive as an input pump wave, and to output a stretched pump wave; and a waveguide configured to receive as an input the stretched pump wave and chirped pulses, and to provide a wave resulting from a four wave mixing.

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: Method and device for the optical parametric chirped pulse amplification, using two pump signals and making it possible to extend the spectral gain band. According to the invention, which is particularly applicable to laser-matter interaction, a four-wave mixing effect is used, preferably in an optical fiber (F), between each pulse (S) and the two pump signals (P1, P2); and the half-sum (fM) of the respective optical frequencies (fP1, fP2) of these signals pertains to the pulse spectrum support.

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: Method and device for the optical parametric chirped pulse amplification, using two pump signals and making it possible to extend the spectral gain band. According to the invention, which is particularly applicable to laser-matter interaction, a four-wave mixing effect is used, preferably in an optical fibre (F), between each pulse (S) and the two pump signals (P1, P2); and the half-sum (fM) of the respective optical frequencies (fP1, fP2) of these signals pertains to the pulse spectrum support.

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.