Patent application number | Description | Published |
20080291530 | Amplifying Medium Comprising a Liquid Medium Based on Halogenated Ligands and Lanthanides - The invention relates to an optical amplifying medium comprising a liquid medium, having an organic ligand corresponding to the following chemical formula: | 11-27-2008 |
20090073452 | SEMICONDUCTOR SOLID-STATE LASER GYRO HAVING A VERTICAL STRUCTURE - The field of the invention is that of solid-state laser gyros used in particular in inertia control systems. This type of equipment is used for example for aeronautical applications. It is possible to produce a solid-state laser gyro from optically or electrically pumped semiconductor media. Currently laser gyros of the latter type are monolithic and small in size. They do not make it possible, on the one hand, to achieve the precision comparable to that of gas laser gyros and, on the other hand, to implement optical methods for eliminating frequency coupling at low rotation speeds or temperature drifts. One subject of the invention is a solid-state laser gyro comprising a semiconductor medium and consisting of assembled discrete elements, thus offering the possibility of producing large cavities for achieving the desired precision. More precisely, the laser gyro comprises an optical ring cavity and a semiconductor amplifying medium with an external cavity having a vertical structure, comprising a stack of plane gain regions that are mutually parallel, the dimensions of the cavity being substantially larger than those of the amplifying medium, said amplifying medium being used in reflection. | 03-19-2009 |
20090084252 | Method For Antimissile Protection Of Vehicles And Implementing Device - 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. | 04-02-2009 |
20090116031 | SOLID-STATE LASER GYRO HAVING ORTHOGONAL COUNTERPROPAGATING MODES - The field of the invention is that of solid-state laser gyros used in inertial control units. However, there are certain technical difficulties in producing laser gyros of this type that are due partly to the fact that the counterpropagating waves interfere with each other in the amplifying medium. A laser gyro according to the invention comprises at least one solid-state amplifying medium and an optical ring cavity comprising first optical means for imposing a first linear polarization state common to the two counterpropagating optical waves at the entrance and exit of the zone containing the amplifying medium and second optical means for imposing, within the amplifying medium, a second linear polarization state on the first optical wave and a third linear polarization state on the second optical wave, these polarization states being perpendicular. Thus, all the drawbacks associated with interference are eliminated. | 05-07-2009 |
20100123901 | Solid State Gyrolaser with Controlled Optical Pumping - The general field of the invention is that of gyrolasers comprising at least one ring-shaped optical cavity comprising at least three mirrors, a solid state amplifying medium pumped by a laser diode whose optical emission power is determined by a current supply source, the cavity and the amplifying medium being such that two so-called contra-rotating optical modes propagate in opposite directions to each other within the said optical cavity, the gyrolaser being a class B gyrolaser, the gyrolaser also comprising means of measuring the difference in optical frequency existing between the two optical modes. The gyrolaser comprises means of measuring the total optical power circulating in the optical cavity and first means of control of the current delivered by the supply source in such a way as to maintain the total optical power substantially constant in a narrow spectral band centred on the relaxation frequency of the laser. | 05-20-2010 |
20100147071 | Matter-Wave Gravimeter Incorporated into an Atom Chip - The general field of the invention is that of gravimeters, of the matter-wave type, allowing the measurement of the gravitational field or of an acceleration in a given direction of measurement. This type of gravimeter uses ultracold atoms to take the measurement. It necessarily comprises an atom trap ( | 06-17-2010 |
20100177317 | Matter-Wave Rate Gyro Integrated onto an Atom Chip and Associated Accelerometer - The general field of the invention is that of rate gyros, of the matter-wave type, allowing the measurement of a speed of rotation in a given direction of measurement. This type of rate gyro works by the Sagnac effect and uses ultracold atoms to perform the measurement. It necessarily comprises an atom trap allowing a cloud of ultracold atoms to be immobilized in a given configuration and means for separation-displacement-recombination of the cloud into two packets of atoms so as to make them trace out a given area. The device according to the invention combines both of these two functions onto one atom chip notably comprising a first conducting wire through which a DC current I | 07-15-2010 |
20100265513 | Solid-state multioscillator ring laser gyro using a <100>-cut crystalline gain medium - A multioscillator ring laser gyro includes an optical ring cavity, a solid-state amplifying medium and a measurement device arranged in such a way that a first linearly polarized propagation mode and a second linearly polarized propagation mode, perpendicular to the first mode, propagate in a first direction in the cavity and in such a way that a third linearly polarized propagation mode parallel to the first mode and a fourth linearly polarized propagation mode parallel to the second mode propagate in the opposite direction. The amplifying medium is a crystal of cubic symmetry having an entry face and an exit face, the crystal being cut so that said faces are approximately perpendicular to the <100> crystallographic direction, the various modes propagating in directions approximately perpendicular to said faces. | 10-21-2010 |
20100265601 | IMAGING MIRROR, METHOD FOR MAKING SAME AND USE THEREOF IN A LASER IMAGING SYSTEM - A mirror for optical imaging includes a reflecting device having a reflective face. The reflecting device incorporates a light-emitting device of which one emitting end is situated in said reflective face in a zone which is not or not very reflective. | 10-21-2010 |
20100272320 | Laser Pointing System - A system for pointing a laser beam is provided. The system comprises at least one processing laser source for emitting a processing laser beam toward a target, said processing beam being transmitted through a non-reflective zone of a first mirror, said mirror allowing return to an imaging system receiving an illumination beam reflected by the target, said low reflection coefficient zone of the first mirror inducing a shadow zone toward the imaging system; a second mirror receiving said processing beam and intended to orient it and reflect it toward the target; an illumination source for illuminating said target with the aid of the illumination beam, a first control circuit for controlling the orientation of said pointing system toward the target, a second control circuit for angularly displacing the processing beam by a determined angle, measuring the distance separating the position of a zone of the target from the position of the spot of the processing beam on the basis of an image obtained by the imaging system, then displacing the illumination beam in the opposite sense by an angle corresponding to said measured distance, the angular displacement of the processing beam having an amplitude such that the measurement of the position of the target is not perturbed by the shadow zone. | 10-28-2010 |
20110019179 | Self-Referenced Optical Fiber Sensor and Related Sensor Network - The general field of the invention is that of fiber-optic sensors comprising at least one measurement optical fiber having an optically pumped doped amplifying medium, the optical characteristics of which are sensitive to a physical quantity, the fiber having at least one Bragg grating. The fiber is designed so as to generate, in the amplifying medium, two optical waves having different optical frequencies that propagate in the same direction after reflection on the Bragg grating and are emitted by the amplifying medium, the two optical frequencies depending on the physical quantity. The two waves may be generated using either a birefringent polarization-maintaining fiber or a DBR (Distributed Bragg Reflector) laser cavity. Notably, this sensor may be used as a hydrophone. | 01-27-2011 |
20110071787 | STABILIZED SOLID-STATE GYROLASER - Solid-state gyrolaser having a device for stabilizing the intensities making it possible to maintain equilibrium of the two counter-propagating modes having at least a means for calculating a rotation measurement (Ω, IΩ) of the gyrolaser on the basis of the counter-propagating modes having a frequency difference (Δνmes) between them, by assuming that the frequency difference (Δνmes) between the two counter-propagating modes is induced only by the rotation of the cavity. The gyrolaser also includes a means for measuring the control command (Co), a means for storing a behaviour model (Mo) of a frequency bias (Δνb) induced by the device for stabilizing the intensities, as a function of the control command, a means for calculating the frequency bias (Δνb) induced by the device for stabilizing the intensities, on the basis of the value of the control command (Co) and the model (Mo), a means for calculating the bias (ΔΩb, ΔIΩb) in the rotation measurement (Ω, IΩ), induced by the frequency bias (Δνb), and a means for compensating for the bias (ΔΩb, ΔIΩb) in the rotation measurement (Ω, IΩ). | 03-24-2011 |
20110122417 | Self-Referenced Optical Fiber Sensor with Stimulated Brillouin Scattering - A sensor is used to measure a physical quantity and includes at least: a measurement optical fiber including at least one Bragg grating; optical means designed to inject, into the fiber, a first, “pump” wave at a first optical frequency and a second, “probe” wave at a second optical frequency, the second optical frequency being different from the first optical frequency, the Bragg grating being designed to reflect the first and second optical waves, and the optical power of the first wave being sufficient to give, after interaction with the second wave reflected by stimulated Brillouin scattering, a “Stokes” wave, the frequency of which is representative of the physical quantity to be measured; and means for analyzing the difference in frequency between the two, “pump” and “Stokes”, optical waves. The sensor may notably be used as a hydrophone. | 05-26-2011 |
20110194119 | SOLID-STATE LASER GYRO OPTICALLY ACTIVE THROUGH ALTERNATING BIAS - The field of the invention is that of solid-state laser gyros used for the measurements of rotation speed or relative angular positions. This type of equipment is notably used for aeronautical applications. The object of the invention is to complete the optical devices necessary to control the instability of lasers by specific optical devices enabling elimination of the dead zone and of population inversion gratings exiting in the amplifying medium. An “all optical” solid-state laser is hence obtained without moveable parts, stable and without a dead zone. To this end, the laser gyro according to the invention comprises notably and optical assembly enabling a nonreciprocal optical phase-shift to be introduced between the counterpropagating modes; and control means allowing the phase-shift amplitude to be varied periodically around a mean value that is very approximately zero. | 08-11-2011 |
20110235658 | High-Power Laser Fibre System - The invention relates a power fiber laser system including at least one single-mode fiber laser, emitting at a signal wavelength, the fiber including at least one outer cladding and a core, in which the core of the fiber has a radially graded index. The fiber includes, at least over a part of its length, a geometrical section having a graded fiber-core radius that decreases between an input end of the section and an output end of the section, the core radius and the index variation between the cladding and the fiber at the input end being such that the normalized frequency at the signal wavelength is less than the normalized cutoff frequency at which the fiber becomes unimodal. | 09-29-2011 |
20110273720 | Multi-Oscillator Solid-State Laser Gyro Passively Stabilized by a Frequency-Doubling Crystal Device - A laser gyro for measuring the angular velocity or the angular position relative to a defined rotation axis includes: an optical ring cavity; a solid-state amplifying medium; and a non-reciprocal magneto-optic device; which are arranged so that four linearly polarized propagation modes can propagate within the cavity, the magneto-optic device introducing a frequency bias between the modes propagating in a first direction and the modes propagating in the opposite direction. In the device, the cavity also includes a stabilizer device for stabilizing the intensity of the four propagation modes at substantially equivalent levels, said device comprising at least one optical element made of a non-linear crystal of the frequency-doubling type. | 11-10-2011 |