Abstract: A light-emission device includes at least one emission module comprising: a luminescent crystal known as a concentrator crystal with at least six faces which are parallel in pairs, including a first and a second face, known as lateral faces, perpendicular to a direction x and separated by a distance corresponding to a horizontal dimension of the concentrator in the direction x; a first mirror, which is configured such as to cover the first lateral face at least partly, defining a surface area covered by the first mirror, and at least one surface area (SFS1) which is not covered by the first mirror defining an associated output face; a second mirror, which is configured such as to cover at least 95% of the second lateral face; a brightness triggering element, which is designed to generate emission of brightness radiation (LF) in the luminescent crystal; a ratio R between the non-covered surface area (SFS1) and a surface area (SL) of the first lateral face being determined such that rays of the brightness radia

Abstract: A light emitting device including a plurality of light emitting diodes (LED) configured to emit an incident light; a solid luminescent concentrator (CL) of index nc including two parallel faces, called large faces (FE1, FE2), along an horizontal plane xy, and n?>2 faces called side faces (FL1, FL2, FL3, F4), at least one of the first and the second large face being illuminated by the incident light (Ld), the concentrator being configured to absorb the incident light (Ld) and then emit a luminescent light (LL), a portion of the luminescent light being guided by total internal reflection (Lg) in the concentrator and passing through a first so-called exit face of the concentrator (FL1) in contact with an exit medium (EM) of index ns<nc, and forming an exit beam; a cooling system (CS) including a cooling medium (CM) in contact with at least one of the faces of the concentrator.

Abstract: A light emitting device including a solid fluorescent material or a solid scintillator material adapted to absorb an incident light and then emit a luminescent light in the material, a portion, called trapped portion, of the luminescent light being trapped by total internal reflections in the material, the material including two parallel faces, called large faces, along an horizontal plane xy, and n?N>2 faces called side faces, and forming vertex between two adjacent side faces and a large face. The material has an invariance of the normals to said side faces by rotation by an angle of 2?/n in said horizontal plan around a z-axis perpendicular to the horizontal plane. The material has a vertex called virtual vertex that is beveled thus forming a surface called beveled vertex, or the material has an edge between two side faces.

Abstract: A light-emission device includes at least one emission module comprising: a luminescent crystal known as a concentrator crystal with at least six faces which are parallel in pairs, including a first and a second face, known as lateral faces, perpendicular to a direction x and separated by a distance corresponding to a horizontal dimension of the concentrator in the direction x; a first mirror, which is configured such as to cover the first lateral face at least partly, defining a surface area covered by the first mirror, and at least one surface area (SFS1) which is not covered by the first mirror defining an associated output face; a second mirror, which is configured such as to cover at least 95% of the second lateral face; a brightness triggering element, which is designed to generate emission of brightness radiation (LF) in the luminescent crystal; a ratio R between the non-covered surface area (SFS1) and a surface area (SL) of the first lateral face being determined such that rays of the brightness radia

Abstract: A laser pumping assembly includes a parallelepipedal solid laser medium having the shape of a plate in a horizontal plane (xy) and a thickness eL, the laser medium having an absorption spectral band and an associated absorption coefficient ?; at least one light emission module intended to pump the laser medium, comprising a fluorescent parallelepipedal crystal called a concentrator, having the shape of a plate of thickness ec?, the concentrator having at least one illumination face illuminated by electroluminescent radiation and being configured to absorb the electroluminescent radiation and emit fluorescence radiation in a spectral range exhibiting an overlap with the absorption spectral band, the concentrator having an emitting face; the concentrator being in optical contact, via the emitting face, with a receiving face of the laser medium, the concentrator being arranged perpendicular to the laser medium such that the one or more illumination faces are perpendicular to the receiving face so as to perform t

Abstract: A frequency converter system includes a source that emits a beam having a wide spectral band; and a frequency conversion cell including 1) a birefringent nonlinear crystal having a first phase-matching wavelength, with an input face that receives the beam, an output face that emits at least one frequency-converted beam, and at least two parallel faces different from the input and output faces; 2) means for applying an external mechanical force to at least one of said two parallel faces, resulting in a variation in the birefringence of the nonlinear crystal, the value of the applied external mechanical force being determined so as to obtain phase matching at a second phase-matching wavelength different from the first phase-matching wavelength; and 3) means for adjusting the external mechanical force for wavelength tunability in the frequency conversion cell.

Abstract: According to one aspect, the invention relates to a frequency conversion cell (10) comprising: a birefringent nonlinear crystal (12) characterized by a first phase-matching wavelength, having an input face (121A) for receiving at least one incident beam, an output face (121B) for emitting at least one frequency-converted beam, and at least two parallel faces (120A, 120B) different from the input and output faces; means (14, 14A) for applying an external mechanical force to at least one of said parallel faces (120A), called a force application face, resulting in a variation in the birefringence of the nonlinear crystal, the value of the applied external mechanical force being determined so as to obtain phase matching in the nonlinear crystal at a second phase-matching wavelength different from the first phase-matching wavelength.

Abstract: According to one embodiment, the invention relates to a laser gain module (1) comprising: a laser rod (5) having a shaft and two optical interfaces (7, 9) facing each other, the rod (5) being used for longitudinal or quasi-longitudinal optical pumping; and a metal cooling body (3), at least one part of which is molded around the laser rod (5) in order to cover all of the surfaces other than the optical interfaces in such a way that the laser gain module (1) forms a solid body that cannot be disassembled at ambient temperature.

Abstract: According to one embodiment, the invention relates to a laser gain module (1) comprising: a laser rod (5) having a shaft and two optical interfaces (7, 9) facing each other, the rod (5) being used for longitudinal or quasi-longitudinal optical pumping; and a metal cooling body (3), at least one part of which is moulded around the laser rod (5) in order to cover all of the surfaces other than the optical interfaces in such a way that the laser gain module (1) forms a solid body that cannot be disassembled at ambient temperature.

Abstract: The present invention relates to a multi-pass three-dimensional amplifier structure in which a beam of light traverses an amplifier medium multiple times via distinct multiple paths. The distribution of the multiple paths being such that the volume occupied by the multiple paths inside the amplifier medium substantially overlaps with the volume of the amplifier medium being optically pumped by an optical pump beam. The distribution of the optical paths is such that no more than two of the multiple paths lie in a same plane. The astigmatism induced by anisotropic amplifying crystals is self-compensated by aligning the crystallographic axes of the amplifying crystal at a 45° angle to the longitudinal axis of the redirecting means.

Abstract: The present invention relates to a multi-pass three-dimensional amplifier structure in which a beam of light traverses an amplifier medium multiple times via distinct multiple paths. The distribution of the multiple paths being such that the volume occupied by the multiple paths inside the amplifier medium substantially overlaps with the volume of the amplifier medium being optically pumped by an optical pump beam. The distribution of the optical paths is such that no more than two of the multiple paths lie in a same plane. The astigmatism induced by anisotropic amplifying crystals is self-compensated by aligning the crystallographic axes of the amplifying crystal at a 45° angle to the longitudinal axis of the redirecting means.

Abstract: A multi-pass three-dimensional amplifier structure in which a beam to be amplified traverses an amplifier medium multiple times through distinct multiple paths. The distribution of the multiple paths being such that the volume occupied by said multiple paths inside the amplifier medium substantially overlaps with the volume of the amplifier medium being optically pumped by an optical pump beam. Also, the distribution of said optical paths being such that no more than two of the multiple paths lie in a same plane.

Abstract: A sub-nanosecond passively Q-switched microchip laser is disclosed. It combines an optically pumped, passively Q-switched, high-frequency, microchip laser producing short pulses with an optically end-pumped amplifier producing high small-signal gain while pumped at low power. The microchip laser for emitting pulsed laser radiation is a monolithic body comprising two reflective elements defining an optical resonator for laser radiation, a laser gain medium, e.g., Nd:YAG, and a saturable absorber medium, e.g., Cr4+:YAG placed inside said resonator. The optical amplifier stage for amplifying the laser radiation comprises an amplifying medium, e.g., Nd:YVO4. The microchip laser and the amplifier are optically end-pumped, preferably by high-brightness diodes. This entirely passive laser system directly produces &mgr;J pulses at repetition rates of about 45 kHz.