Abstract: Disclosed is an optical-fibre laser system including an injector generating a source pulse, a spectro-temporal shaping module, at least one final optical-fibre amplifier having a length less than ten metres, the final amplifier being suitable for receiving a filtered pulse from a spectral filter and generating an amplified pulse with controlled chirp, a volume compressor which has a predetermined linear chirp and is suitable for receiving the amplified pulse and forming a compressed pulse having a duration of less than 3 picoseconds and an electronic unit for adjusting the duration of the compressed pulse, the electronic duration adjusting unit being formed by adjusting the energy of the source pulse and/or the amplified pulse, the duration of the compressed pulse being tunable according to the energy setting.

Abstract: An ophthalmic surgical apparatus includes: a laser source emitting a beam of one picosecond to one nanosecond pulses; an optical system focusing the beam on a focal point; and a system for moving the focal point along a predetermined path. The laser source generates the beam, focused next to a surface of the anterior segment of the eye, the focal point located at a distance from an optical axis of symmetry of the anterior segment of the eye. The system for moving the beam includes a single degree of freedom of rotation about an axis of rotation to move the focal point along a curved path located in an annular area about the optical axis of symmetry of the anterior segment of the eye. The ophthalmic surgical apparatus has a numerical aperture limiting the geometric optical aberrations at the focal point and on the entire curved path.

Abstract: The invention relates to an optical amplifier system for amplifying laser pulses, including a solid amplifying medium capable of receiving a beam of laser pulses to be amplified and generating a beam of amplified laser pulses, and a means of reducing the energy stored in said optical amplifying medium by means of optical pumping. According to the invention, said reducing means includes a continuous resonant cavity and a first optical separation means capable of sepaarating continuous resonant cavity into a common portion and a low arm, the common portion including an optical amplifying medium and the loss arm inlcuding an optical loss means, said optical separation means being capable of selectively directing a beam of pulses outside the optical path of said loss arm of the continuous resonant cavity, and of directing a continuous bean toward said loss arm of the continuous resonant cavity.

Abstract: A device for extending the lifetime of a frequency-converting non-linear optical system (19) subjected to the radiation of an intense laser beam includes two plates (2, 3) with flat and parallel surfaces angled on the beam and elements for transverse rotation of the plates (2, 3) suitable for changing the angle of inclination of the first plate in an angular range (i20±?i2) to move the incident beam relative to the optical system (19), while minimizing the amplitude of movement of the output beam (37, 47) on the angular inclination range (i20±?i2) of the first plate. The application of the device in a non-linear optical source including one or more non-linear crystals (1, 16) is also described.

Abstract: An apparatus includes a pulse conditioner and an amplifier. The pulse conditioner configured modifies a temporal intensity profile of an input laser pulse, thereby creating a conditioned laser pulse having conditioned temporal intensity profile with a misfit parameter, M, of less than 0.13, where: M 2 = ? [ ? ? ? 2 - ? ? Pfit ? 2 ] 2 ? ? t ? ? ? ? 4 ? ? t , where |?(t)|2 represents the pulse temporal intensity profile of the conditioned laser pulse and |?Pfit(t)|2 represents a parabolic fit of the conditioned laser pulse. The amplifier increases the power of the conditioned laser pulse creating an amplified laser pulse. In a method a temporal intensity profile of an input laser pulse having a pulse duration of at least 1 ps is modified to create a conditioned laser pulse, which is amplified to create an amplified laser pulse, which is temporally compressed to generate a compressed laser pulse having a compressed pulse duration less than the input pulse duration.

Abstract: The disclosure relates to a laser device having a fibre emitting a single-mode transverse radiation controlled at a given wavelength, which includes: at least one laser diode capable of emitting a pump wave and a sheathed amplifying optic-fibre segment having two ends, the amplifying optic fibre including a core and a pumping sheath, the fibre being doped with a rare-earth dopant, wherein the core of the fibre has a diameter of between 12 ?m and 200 ?m, and in that the device includes: a coupling means for coupling the pump wave in the pumping sheath to at least one end of the fibre, and a resonator capable of re-injecting a laser beam at the given wavelength at the two ends of said segment, said resonator including an intra-cavity wavelength selective means capable of interaction with the injection means so as to perform a filtration on the given wavelength and re-inject into the fibre the pump wave which has not been absorbed after passing in the fibre.

Abstract: A device for extending the lifetime of a frequency-converting non-linear optical system (19) subjected to the radiation of an intense laser beam includes two plates (2, 3) with flat and parallel surfaces angled on the beam and elements for transverse rotation of the plates (2, 3) suitable for changing the angle of inclination of the first plate in an angular range (i20±?i2) to move the incident beam relative to the optical system (19), while minimising the amplitude of movement of the output beam (37, 47) on the angular inclination range (i20±?i2) of the first plate. The application of the device in a non-linear optical source including one or more non-linear crystals (1, 16) is also described.

Abstract: The invention relates to a high-power fiberoptic laser device comprising at least one laser diode (1) capable of transmitting a pump wave, a triggered optical resonator (22) consisting of a first double-sheathed optical fiber (6), an optical amplifier consisting of a second double-sheathed optical fiber (10), first (33) and second (35) optical coupling means capable of coupling said pump wave onto at least one of the two optical fibers (6) and (10). According to the invention, at least one of the two fibers has a configuration according to which the pump wave coupled to this optical fiber (6) or (10) is partially absorbed, generating a residual pump wave which is coupled to the other optical fiber (6) or (10) by second optical coupling means, and said second optical fiber (10) has a length greater than that of the first optical fiber (6).

Abstract: A power fibre laser device includes a power laser diode emitting a pump wave, an optical resonator including fully reflective and partially reflective ends, an amplifying multimode optical fibre, and an optical element coupling the pump wave in the multimode optical fibre. The optical resonator includes at least one submodule consisting of a spatial filtering element and including an optical element having a definite position in the optical submodule so as to enable the optical submodule to reproduce, after a round trip of the laser beam, the amplitude and phase of the fundamental mode of the multimode optical fibre to the input or output face of the multimode optical fibre, whereby minimising losses in the fundamental mode, and enabling the optical submodule to filter the other modes, producing additional losses in the modes in the optical resonator, whereby minimising the number of laser modes that propagate in the optical resonator.

Abstract: A composite optic fibre for laser includes a core surrounded with a pump guiding sheath in contact with the core, sheath being a photonic structure formed by a substantially regular matrix assembly of coaxial capillaries, spaced apart and arranged parallel to the core, the core being a material with doping elements which may be brought into at least one excited electronic state by absorbing the energy from a pump optical signal of a first determined wavelength running through the core and capable of giving-back the former by de-energization in the form of an optical signal of a second determined wavelength, the core having a determined diameter and the sheath having a determined diameter. The diameter of the guiding sheath is greater than the core diameter and smaller than or equal to four times the core diameter, the core diameter being greater than or equal to 35 micrometers.

Abstract: The invention relates to a high-power fiberoptic laser device comprising at least one laser diode (1) capable of transmitting a pump wave, a triggered optical resonator (22) consisting of a first double-sheathed optical fiber (6), an optical amplifier consisting of a second double-sheathed optical fiber (10), first (33) and second (35) optical coupling means capable of coupling said pump wave onto at least one of the two optical fibers (6) and (10). According to the invention, at least one of the two fibers has a configuration according to which the pump wave coupled to this optical fiber (6) or (10) is partially absorbed, generating a residual pump wave which is coupled to the other optical fiber (6) or (10) by second optical coupling means, and said second optical fiber (10) has a length greater than that of the first optical fiber (6).

Abstract: A rare earth ion ultrashort laser source includes a resonant cavity having a first output face partially reflecting and a second reflecting face. The source also includes a first active material, which receives a pump luminous flux transmitted via a first solid laser pump source. The resonant cavity exhibits a length of optical path travelled by the pulses greater than 7.5 m so that the pulsed energy EL is greater than 100 nJ, the optical path including at least one passage in the active material and the ultrashort laser source includes elements for lengthening the resonant cavity thereby enabling to extend the length of the optical path travelled by the luminous pulses in the resonant cavity, the ABCD propagation matrix of the resonant cavity being close to the unit matrix so that the features of the luminous beam going back and forth in the resonant cavity remain unchanged.

Abstract: A laser femtosecond microtome for cutting out by a focused laser beam at least one slice of material in a material block, wherein the block includes a front surface and the slice carrying the front surface, the slice extends at least partially substantially in a X, Z plane perpendicular to an axis Y of the block thickness, the slice is separated from the remaining part of the block by a cleavage surface formed by an assembly of bubbles brought together, each bubble is formed in a focus area of at least one convergent laser beam pulse of an optical axis L. According to the invention, the optical axis L of the convergent part (3) of the laser beam forms an angle ranging between ?45° and ±45° relative to the X, Z. The ellipsoid-shaped focus area has its smaller axis in the direction of the axis Y.

Abstract: The invention relates to a rare earth ion ultrashort laser source including a resonant cavity (1) having a first output face (2) partially reflecting and a second reflecting face (3). Said source also comprises a first active material (4). Said first material (4) receives a pump luminous flux (6) transmitted via a first solid laser pump source (7). According to the invention, the resonant cavity (1) exhibits a length of optical path travelled by said pulses greater than 7.

Abstract: The invention relates to a composite optic fibre (1) for laser comprising a core (2) surrounded with a pump guiding sheath in contact with the core, the pump guiding sheath (4) being a photonic structure formed by a substantially regular matrix assembly of coaxial capillaries, spaced apart and arranged parallel to the core in a pump guiding sheath material, the core being in a core material with moreover doping elements which may be brought into at least one excited electronic state by absorbing the energy from a pump optical signal of a first determined wavelength running through said core and capable of giving-back the former by de-energization in the form of an optical signal of a second determined wavelength, the core having a determined diameter and the pump guiding sheath having a determined diameter.

Abstract: Non-linear single crystal obtained by crystallization of a congruent molten composition of general formula:M.sub.4 LnO(BO.sub.3).sub.3in which:M is Ca, or Ca partially substituted with Sr or Ba;Ln is one of the lanthanides of the group comprising Y, Gd, La and Lu.

Abstract: A spectrum analyzer for a variable amplitude and frequency electric signal includes an optical modulator responsive to the signal that derives a first optical wave having intensity and frequency components corresponding to the signal amplitude and frequency components. An optical analyzer responds to the first optical wave to derive a second optical wave having intensity variations at frequency components corresponding to the amplitude of the electric signal at the frequencies in the spectrum of the signal. The optical analyzer includes a tunable optical cavity responsive to the first optical wave to derive the second optical wave.