Abstract: This system comprises at least one optical sensor (C1, C2, C3) comprising two Bragg gratings (B11, B12; B21, B22; B31, B32) written in two optical waveguides and having sensitivities adjusted so that the respective spectra of the two gratings have a relative spectral shift which depends on the parameter or parameters to be measured. The system also comprises an optical source (6) provided in order to supply light to the two optical waveguides so as to interrogate the latter, means enabling the light to pass successively through the two Bragg gratings of the same sensor, photodetectors in order to measure, on the one hand, the power level of light (R1) having passed only through one of the two optical waveguides and, on the other hand, the power level of light (R′1) having passed successively through the two optical waveguides, and means to process these power levels and supply the values of the parameter or parameters measured.

Abstract: According to the invention, that relates particularly to monitoring of structures, part of the optical fiber (4) containing a Bragg grating (R) is arranged in a tube (16); this part is tensioned between the two ends of the tube; the ends of this part are fixed to the ends of the tube; this tube will be rigidly fixed to a host material (2).

Abstract: A Bragg grating inclinometer that includes an upper part, a lower part forming a pendulum suspended from the upper part by an articulation, at least two portions of optic fiber placed on either side of the articulation, the ends of each portion being fastened to the two parts, each portion being previously put under tension between the two parts, and at least one Bragg grating in one of the portions. Any variation in the inclination of a structure to which the upper part is fastened induces a stress on the grating, which then modifies a light propagating in the portion where it is placed. The variation in inclination is determined from the modified light. The inclinometer can be applied in particular to the surveillance of civil engineering structures.

Abstract: This device comprises a device (DD) for demultiplexing these lines in terms of wavelength, a device (DM) for measuring, by filtering, the wavelengths of the demultiplexed lines, comprising, for each of these lines, a measuring channel (VM) provided with a filter and a reference channel (VR), and means (MP) for the photodetection, for each line, of the light intensity transmitted by the corresponding measuring and reference channels. The wavelength of each of these lines is determined by calculating the ratio of the intensities thus detected. Application to the monitoring of structures.

Abstract: In order to measure the refractive index of a medium (18), for example a liquid or a gas, this system comprises a waveguide (14) having a blazed Bragg grating (16), the spectral response of which depends on the refractive index of the medium, a light source (20) in order to make this light interact with the grating, means (22) for the spectral analysis of the light which has interacted with the grating, means (24) for recovering the spectrum provided by the spectral analysis means and means (26) to correlate, from the recovered spectrum, the spectral response of the grating with one value of the refractive index of the medium.

Abstract: This inclinometer comprises an upper part (4), a lower part (6) forming a pendulum suspended from the upper part by an articulation (8), at least two portions of optic fibre (20, 22) placed on either side of said articulation, the ends of each portion being fastened to the two parts, each portion being previously put under tension between said parts, and at least one Bragg grating (24) in one of the portions. Any variation in the inclination of a structure to which is fastened the upper part induces a stress on the grating, which then modifies a light propagating in the portion where it is placed. The variation in inclination is determined from the modified light. The invention applies in particular to the surveillance of civil engineering structures.

Abstract: The present invention relates to a device for demultiplexing spectrum lines contained in an optical spectrum. This device comprises a energy separator (2a, 2b, 2c) and selective wavelength light reflectors (12), each selective wavelength light reflector having a wavelength bandpass that contains the spectral region associated with one of the lines and that, therefore, reflects only this particular line. Applications to surveying constructions, such as buildings and aircraft.

Abstract: The present invention relates to a planar, rosette-type, optical microsystem with strain gauges having dielectric guides used for measuring a system of strains or stresses applied to a part, in which the part is under purely longitudinal strain, at least one rosette being formed by at least two strain gauges with dielectric guides (J1, J2, J3) and in which a calculating circuit makes it possible to determine said strain by resolving a system of equations.

Abstract: The present invention relates to a high capacity, high signal-to-noise ratio sensor incorporating an array of Bragg grating transducers photoinscribed on a dielectric guide and a feedback loop incorporating a wavelength selective element which is time modulated making it possible to obtain a laser sensor selectively switched by each Bragg grating.Application to monitoring strains or temperatures in a structure.

Abstract: The interferometer comprises an emitter arm (10) excited by a source (11) and a receiver arm (20) associated with a photodetector (21) united by an optical coupler (50) so as to form a reference arm (30) and a measurement arm (40) terminating in a sensor (41). The arms (30) and (40) are constituted by one and the same optical fiber whose diopter of its free end (31) acts as a partially transparent mirror for the reference optical wave. This end (31) is coupled to the sensor (41) which returns the measurement optical wave through said diopter. Application in particular in the measurement of temperatures, for example in turbo-machines or of fluctuations of flow density.

Abstract: CLAIM The ornamental design for holder for game tiles, as shown and described. DESCRIPTION FIG. 1 is a perspective view of a holder for game tiles, showing our new design, the design in an assembled position; FIG. 2 is a front elevational view of one of the end pieces shown broken away for clarity, the rear being identical; FIG. 3 is a right side elevational view of FIG. 2, the left side being identical; FIG. 4 is a bottom plan view of FIG. 2; FIG. 5 is a front elevational view of the intermediate front pieces, shown disassembled and without the end pieces for clarity; FIG. 6 is a left side elevational view of FIG. 5, the right side being a mirror image; FIG. 7 is a top plan view of FIG. 5, the bottom plan being a mirror image; FIG. 8 is a cross-sectional view of the lower half of the intermediate front pieces in FIG. 5; FIG. 9 is a front elevational view of the left side of one of the two pieces shown in FIG. 5, shown disassembled for clarity, the right side being a mirror image; FIG.