Abstract: The invention relates to a method of spectral control in a frequency-shift laser chain for producing ultra-short pulses and comprising at least two laser-crystal amplifier stages, for cooling the crystal of one of the amplifier stages of the chain.

Abstract: The field of the invention is that of high-energy laser beam amplifiers and associated optical pumping devices. The object of the invention is to use an amplifier configuration and a cooling means which do not have the drawbacks of cryogenic systems that have been used up until now and which however make it possible both to obtain an amplified laser beam of high quality and to minimize transverse lasing effects. A laser beam amplifying device according to the invention combines four main principles, which are use of a crystal exhibiting circular symmetry so as to distribute the mechanical stresses radially; cooling of the entire external surface by a cooling liquid, so as to avoid the use of cryogenic techniques; use of a matching liquid so as to avoid transverse lasing effects; and use of pump laser beams with uniform energy distribution.

Abstract: The invention relates to a method of spectral control in a frequency-shift laser chain for producing ultra-short pulses and comprising at least two laser-crystal amplifier stages, for cooling the crystal of one of the amplifier stages of the chain.

Abstract: The present invention relates to a device for coupling between a plasma column serving as an antenna and an electric power signal generator, associated with a laser. This device comprises at least two conducting electrodes, each pierced with a hole, these holes being coaxial, the electrodes being connected on the one hand to a high voltage direct current source and on the other hand to power signal alternating current source, the laser(s) being placed do that its (their) beam arrives along the axis of said holes of the electrodes.

Abstract: The present invention relates to a method for antimissile protection of vehicles having a very short response time with practically no false alarms and not requiring the use of means such as decoys or conventional laser jammers, while providing the best possible protection. It is characterized in that at least one curtain of plasma filaments is created between these vehicles and the probable launch point of these missiles, this curtain being intended to blind the target-seeking device of the missiles.

Abstract: The invention relates to a method of amplifying a laser beam which includes steps consisting in performing an optical pumping of an amplifying crystal so as to inject into the crystal an optical pumping energy Etotal, amplifying the laser beam by means of the amplifying crystal and an optical system with N passes, that is, designed to inject the laser beam into the amplifying crystal N times, N being an integer>1. The optical pumping is temporally divided into n partial pumpings, the optical energy of a partial pumping being a fraction of Etotal, n being an integer 2?n?N and in that the laser beam is injected into the amplifying crystal at least once after each partial pumping.

Abstract: The present invention relates to a method for antimissile protection of vehicles having a very short response time with practically no false alarms and not requiring the use of means such as decoys or conventional laser jammers, while providing the best possible protection. It is characterized in that at least one curtain of plasma filaments is created between these vehicles and the probable launch point of these missiles, this curtain being intended to blind the target-seeking device of the missiles.

Abstract: The field of the invention is that of high-energy laser beam amplifiers and associated optical pumping devices. The object of the invention is to use an amplifier configuration and a cooling means which do not have the drawbacks of cryogenic systems that have been used up until now and which however make it possible both to obtain an amplified laser beam of high quality and to minimize transverse lasing effects. A laser beam amplifying device according to the invention combines four main principles, which are use of a crystal exhibiting circular symmetry so as to distribute the mechanical stresses radially; cooling of the entire external surface by a cooling liquid, so as to avoid the use of cryogenic techniques; use of a matching liquid so as to avoid transverse lasing effects; and use of pump laser beams with uniform energy distribution.

Abstract: The present invention relates to a device for coupling between a plasma column serving as an antenna and an electric power signal generator, associated with a laser. This device comprises at least two conducting electrodes, each pierced with a hole, these holes being coaxial, the electrodes being connected on the one hand to a high voltage direct current source and on the other hand to power signal alternating current source, the laser(s) being placed do that its (their) beam arrives along the axis of said holes of the electrodes.

Abstract: The invention relates to a method of amplifying a laser beam which includes steps consisting in performing an optical pumping of an amplifying crystal so as to inject into the crystal an optical pumping energy Etotal, amplifying the laser beam by means of the amplifying crystal and an optical system with N passes, that is, designed to inject the laser beam into the amplifying crystal N times, N being an integer>1. The optical pumping is temporally divided into n partial pumpings, the optical energy of a partial pumping being a fraction of Etotal, n being an integer 2?n?N and in that the laser beam is injected into the amplifying crystal at least once after each partial pumping.