Abstract: An underwater connector half includes a base and at least two electrical connection terminals respectively connected to two electric wires received in at least one cable. The two electrical connection terminals are ring-shaped and coaxial about an axis located along a direction of assembly of a complementary connector half and the base has a side wall that is parallel to the axis and through which passes the cable. An underwater connector including such a connector half is also disclosed.

Abstract: A cartridge includes an outer case, partially filled with electrically insulating gel, and at least one electrically conductive track submerged in the insulating gel. Connection sets including at least one connector half and such a cartridge are also disclosed.

Abstract: A device for supporting chromophore elements comprises a plane mirror covered in a layer of material that is transparent at the wavelengths to be detected, said layer having a set of spots on which the chromophore elements are fixed, the spots being subdivided into a plurality of zones of different thicknesses so as to cause the intensity of the fluorescence emitted by the chromophore elements to vary by destructive interference or by constructive interference, respectively.

Abstract: The invention relates to a broadband light source including an amplifying guide structure (1). The light source includes a device (45) of exciting the guide structure (1). The stimulated guide structure (1) emits light (7, 8) that accepts strong spatial coherence and weak time coherence. The light (7) is transmitted forwards (2) having a spontaneous emission spectrum. The light source also includes a rear mirror (5), reflecting only for a narrower range of wavelengths than the spontaneous emission spectrum and produces emission (E) forwards (2) with an emission spectrum controlled around an average wavelength. The rear mirror is inserted between the excitation means and the guide structure.

Abstract: A ring interferometer device is provided comprising monomode optical fiber, a radiation separator and a mode filter coupled optically to a coherent light source. In a first approach, this source is a semiconductor diode of the type operating alternately as light emitter and receiver depending on the biasing. In a second approach, the source is a light emitting semiconductor diode coupled by its front face to the mode filter and by its rear face to a detector, said diode acting as light amplifier.

Abstract: The discriminating device comprises an optical coupler (4) having at least three ends (5 to 8) to which are connected a semiconductor source of light (1) whose intensity is modulated, a semiconductor photoconductor (2) and an optical probe constituted by a multi-mode optical fibre (3) whose end has a pointed shape. This discriminating device is in particular applicable in a device for measuring the voluminal fraction of at least one fluid of a current of non-mixible fluids.

Abstract: The sensitive display device of the invention comprises a scanned screen in front of which is situated a plate of transparent material; a detector being coupled with the edge of this plate and a specific position on this plate being determined by contact of a diffusing object, such as a finger. The detector picks up a signal which, after processing, enables the position of this point of contact to be determined. The invention may be used, in particular, as an interface between a computer and a user.

Abstract: A ring interferometer device is provided comprising monomode optical fiber, a radiation separator and a mode filter coupled optically to a coherent light source. In a first approach, this source is a semiconductor diode of the type operating alternately as light emitter and receiver depending on the biasing. In a second approach, the source is a light emitting semiconductor diode coupled by its front face to the mode filter and by its rear face to a detector, said diode acting as light amplifier.

Abstract: In an optical fiber sensor, the fiber has a sensitive zone which cooperates with a retroreflecting surface through the agency of an optical couplant. The function of the retroreflecting surface is to return into the optical fiber all light losses which escape from the fiber in the sensitive zone.

Abstract: A method of coiling an optical fiber gyroscope and an optical fiber coil thus obtained, which method consists in coiling, on a cylindrical support comprising a central channel, a first layer for forming a helical optical fiber winding with constant pitch, passing the optical fiber through the central channel in the form of a single turn and coiling additional layers, in the same direction as the first layer, using the interturn spaces of the underlying layers.

Abstract: The device for measuring a nonreciprocal phase shift involves phase modulation of countercirculating waves in a closed-loop interferometer by means of a reciprocal-effect phase modulator. The modulating signal is a periodic signal having a period 2t.sub.o, where t.sub.o is the transit time of an electromagnetic wave in the closed loop. A digital phase ramp generated in the form of a stair-step signal is combined with the phase-modulating signals and applied as feedback. In an additional embodiment, control circuits are provided for correcting the modulation scale factor.

Abstract: An interferometric device for measuring an angular rotational speed comprising an amplifying photo refractive crystal placed in the path of optical guide means forming a closed loop. Two signal waves penetrate into said crystal so as to obtain two contrarotating waves of different optical frequencies and of amplitudes restored by amplification in the crystal, moving in said closed loop.

Abstract: A holographic process is provided for recording-reading by means of index strata in the volume of a photoexcitable storage medium. This process consists in causing two beams to interfere in this medium during two successive writing steps by using writing radiations of different wavelengths. The reading of this medium is then effected by means of a third coherent radiation having for wave vector in the medium a linear combination of the wave vectors of said writing radiations.

Abstract: The invention relates to the interferometric detection of reciprocal and non-reciprocal effects affecting the propagation of optical radiation in a two-armed interferometer. The invention relates to a two-armed interferometer terminating by a photorefractive medium used as an interactive reflector according to the four-wave interferometer principle.The invention particularly applies to the measurement of physical quantities such as displacement, linear velocity, angular velocity, magnetic field, pressure and temperature.

Abstract: The invention relates to a process and device for measuring the optical core - mechanical sheath concentricity and the optical core ellipticity of an optical fibre. The process consists of injecting a light beam into a fibre, which has been previously bared at one of its ends. The analysis of the near field of this fibre by a detector performing a relative rotary movement with respect to said fibre provides details on the core - sheath concentricity and the core ellipticity, by carrying out a narrow band detection at the rotational frequency and at double its frequency.

Abstract: The invention relates to a device for measuring a magnetic field, comprising a source of rectilinearly polarized light. A magnetooptical medium is situated in the path of the beam, this medium being followed by a mirror refecting this beam. This medium is a medium of which the intrinsic propagation modes are polarized in right-hand and left-hand directions, and which retains the circular polarization. An element acting as a separator by polarization is situated between the source and the medium, a detector device being coupled to the same.

Abstract: The invention provides a process for forming a fiber keeping a circular polarization and a device for implementing this process.This process consists, during drawing and twisting of the fiber from a formable material source, in remelting on the surface a part of the volume of said fiber in a zone where it is subjected to twisting stresses.

Abstract: A heating device including a carbon dioxide laser beam directed towards a spherical mirror and then directed from an ellipsoidal mirror so as to concentrate the energy of said laser on a surface ring of a threadlike object.

Abstract: The invention relates to electro-optical media which make it possible to record holograms in real time. It consists in using a lamina of a selected material such as bismuth-silicon oxide, this lamina being subjected to a transverse electric field perpendicular to the fringes of the hologram to be inscribed, and in illuminating this lamina with a light beam which is not coherent with the two object and reference beams which interfere within this lamina.

Abstract: Optical fibre interferometer for measuring a current carried by a high voltage line of the type comprising a winding traversed by a feedback current, having at least one base at earth potential, incorporating the interferometer core and the feedback winding, an insulating member and a measuring head mounted on a conductor traversed by the current to be measured. The insulating member is a rigid member forming a support or, in a preferred variant, a tubular insulating member having a flexible wall and provided with skirts made from an insulating material with a rounded "water droplet" profile.