Abstract: A device for determining the phase errors of electromagnetic waves (OE) which are generated by a light source and transmitted by an optical instrument includes a reception system (SM) having at least one measurement plane (PM, PM3, PM4) provided with a plurality of measurement zones (ZM) which can measure the intensity of the received light and a collimation means (L1) for sending to the measurement plane (PM, PM3, PM4) the electromagnetic waves (OE) transmitted by the optical instrument.

Abstract: A diode laser device includes a heat diffusing substrate made from a material that is a good conductor of heat, in one face of which is formed a system of parallel ribs and grooves, the ribs being identical and equidistant, and a plurality of semiconductor arrays incorporating the diodes and housed longitudinally in the grooves. The grooves have an at least approximately triangular cross-section joined to the substrate by one side and each semiconductor array is fixed flat to an oblique flank of one of the ribs.

Abstract: The present invention relates to a device for determining the shape of the wave surface reflected by a substantially plane component (P), which includes a support (S) for the component (P), an interferometer (I), means for moving the support (S), and a control unit which determines, from the measurements by the interferometer (I), the shape of said wave surface.According to the invention, the device additionally includes a swivelling mirror (M1), which directs the measurement beam (FM) of the interferometer (I) orthogonally onto a surface (2) of the component (P), and an optical sensor (CO), which determines the position of the image of a light point (PO) of the measurement beam (FM), the orientation of the mirror (M1) being controlled in such a way as to bring the light point (PO) back to a reference position automatically.

Abstract: The present invention relates to a device for determining the shape of the wave surface transmitted by a substantially parallel-faced transparent component (P), which includes a support (S) for the component (P), an interferometer (I), means for moving the support (S), and a control unit which determines, from the measurements by the interferometer (I), the shape of said wave surface. According to the invention, the support (S) is made in such a way as to let the light beam (FM) emitted by the interferometer (I) and transmitted by the component (P), which is transparent, pass through it, and said device includes a swivelling mirror (M1) arranged approximately orthogonally to the beam (FM) transmitted by the component and oriented in such a way as to send said beam (FM) back in the emission direction (D1).

Abstract: A mirror having a reflection coefficient that is spatially variable in amplitude and in phase includes at least two parallel spaced reflecting plates. One of the plates is displaced parallel to itself to vary the distance between the plates. At least one of the reflecting plates can be deformed transversely to its plane.

Abstract: According to the invention, the Brillouin-effect radiation created in the Raman cavity (14) is returned into the pumping laser (1) to increase the Raman output power.

Abstract: The generator is excited by an electric discharge through the gas between two electrodes (6, 7), at least one of which (6) is made of silicon carbide.

Abstract: A laser device for guiding a missile to a target such as an enemy tank, includes a laser transmitter (1) which transmits radiation (2) which is received by a modulator (30) capable of delivering two distinct pulsed beams (51, 52) in response thereto. The first beam (51) is directed to a missile (7) to measure the angle and the distance of the missile and to convey piloting instructions thereto by modulation of said pulses, and the second beam (52) is directed towards a target (55) by a reflector (54) mounted on an aiming sight (22) in order to measure the distance to the target. The device further includes a computer (28) for determining the trajectory to be followed by the missile towards the target on the basis of the distances to the missile and to the target and on the basis of the angle between said distances.

Abstract: An X-ray generator 7 directly connected to the electrode 8 internally of a hollow cathode 3 emits electrons under a field effect to generate X-rays, the generator 7 supplying 50 to 100 Kv with a rise time of less than 10 nanoseconds. X-rays rapidly created, in turn, rapidly create electrons in the active medium 1 between anode 2 and cathode 3 to trigger a discharge therebetween, across which anode and cathode the voltage of a laser capacitor is pre-applied at a level below the breakdown voltage of the active medium.

Abstract: Apparatus for the detection of an enemy infrared camera. This apparatus includes a continuous infrared laser 1 directed towards camera 25, a receiver 10 of the infrared signals sent by the camera, a processing circuit 23 of these signals, able to determine a delay time, a delay circuit 22 supplying electrical signals delayed by the said delay time in relation to the reception of infrared signals, and a pulsed laser 16 sending to camera 25 laser pulses respectively on reception of the delayed signals. The apparatus causes a very bright spot to be created on the camera screen which represents a picture of a dummy object displaced by a predetermined distance from the apparatus. This spot overshadows the spot on the screen corresponding to the true location of the apparatus.Application is for detection of an enemy infrared camera placed on a tank.

Abstract: A source of light (F1, 34) directs a light beam (35) towards an object. A photoelectrical measuring system (39) includes three measurement detectors (40, 41, 42) having respective reception fields (44, 45, 46). These fields overlap partially, and all of them share a volume of space in common with the beam (35). A reference photoelectrical system (F2, 36) detects light diffused by an object anywhere in said common volume. A processing system determines the distance of the object in said common field as a function both of which of the measurement detectors is detecting light diffused by the object and of the ratio between the measurement signal detected thereby and the reference signal from the reference system. The apparatus may be used to equip the pincers of an industrial robot.

Abstract: Apparatus having application to surgical operations has an ultra-violet laser pulse generator (1), an infrared laser pulse generator (3), an optical fibre (11) which transmits these pulses in one direction to the organ (13) and returns the fluorescence emitted by the organ together with reflected infrared radiation. Said returned radiation is detected by two receivers (25 and 20) and a circuit (31) for processing the electric signals delivered by said receivers.

Abstract: In a system for tracking a target which is illuminated by a laser beam, for example, apparatus is required to determine how far the target is off-axis. The apparatus includes an objective lens (3) which concentrates light coming from the target onto a reception surface (8). A group (12) of bundles (13,14,15,16) of optical wave guides is disposed between the reception surface (8) and a single photoelectric receiver (21). Each bundle conveys light from a respective portion of the reception surface. The bundles (13,14,15,16) of wave guides are of different lengths. Thus, the optical signals transmitted by the various bundles are received successively by the single receiver. This avoids problems of matching the sensitivity of different receivers responsive to different portions of the reception surface.

Abstract: The invention relates to a device for determining the granulometric composition of a mixture of particles by diffraction of light. The light flux received on the diffraction pattern is measured in a number of diffraction areas (AI,AJ) each of which is in the shape of an angular sector of circular rings which are concentric with the pattern, these integration areas forming two successions in each of which the inner and outer radii form geometrical progressions with common ratio of two, the ratio between the outer radius and the inner radius of an integration area being chosen in the interval between two and the square root of two, the radii within one succession (AJ) being equal to those within the other (AI) multiplied by the square root of two. Application to studying powder mixtures.

Abstract: The invention relates to a device for cooling a laser head by a flow of liquid. A tank of this liquid, is provided at the upper part of the device and has a membrane which is impermeable to the liquid and permeable to gases. Application to solid laser generators with triggered operation and a high repetition rate.

Abstract: The telemeter e.g. for tanks or aeroplanes, includes in particular a diaphragm disposed in the optical receiving system, the diaphragm is provided with closing means which operate outside the period during which a measuring echo is expected so as to protect the receiver of the telemeter against any interference light pulse (except during said measuring period). This reduces the risks of serious damage to the receiver from counter-measure laser pulses.

Abstract: A laser generator (1,2,3) is arranged to generate successive pairs of pulses. Two light receivers (10,11) in the vicinity of the laser generator receive echos of the pulses as reflected from a target and a processing circuit (15) calculates the component of wind speed blowing across the laser axis between the laser generator and the target. The device can be combined with laser ranging means and used for artillery control.

Abstract: The invention relates to a laser telemeter, which includes a cell (8) containing a saturable absorbent material disposed between the laser generator (1) and the optical emission system (9, 10), to prevent false readings due to back scattering of the non-coherent fluorescent radiation emitted in conjunction with a laser pulse. The telemeter can be used to equip tanks and aircraft.

Abstract: The invention relates to a laser generator. That generator comprises optical resonant cavity of the folded type, limited by two plane mirrors arranged in a same plane, side by side and a corner cube reflector for sending back the radiation coming from one of the said mirrors towards the other mirror. Application to telemeters and to illuminators.