Abstract: A holder and at least one terminal element that are configured and arranged with respect to one another so as to form a cavity of length ?L bounded axially by two walls the relative position of which with respect to each other varies in the opposite direction to the variation in ambient temperature, an increase in temperature causing the walls to move closer together and vice versa. A linear structure incorporating the device sees its length decrease when temperature increases and vice versa. Electro-optical transducers comprising a piezoelectric actuator of linear structure that acts on the length of a segment of optical fiber that forms the laser source of the transducer, and having such a device incorporated into the actuator in order to compensate, by modifying the length of the segment of fiber, for the variations in wavelength induced in the laser by the variations in temperature.

Abstract: A holder and at least one terminal element that are configured and arranged with respect to one another so as to form a cavity of length ?L bounded axially by two walls the relative position of which with respect to each other varies in the opposite direction to the variation in ambient temperature, an increase in temperature causing the walls to move closer together and vice versa. A linear structure incorporating the device sees its length decrease when temperature increases and vice versa. Electro-optical transducers comprising a piezoelectric actuator of linear structure that acts on the length of a segment of optical fiber that forms the laser source of the transducer, and having such a device incorporated into the actuator in order to compensate, by modifying the length of the segment of fiber, for the variations in wavelength induced in the laser by the variations in temperature.

Abstract: The invention relates to a surface acoustic wave resonator produced on a cut substrate with propagation axes for which a nonzero directivity exists and comprising at least one central transducer (Tc) exhibiting a central axis, a first array of reflectors (R1) and a second array of reflectors (R2), said arrays being situated on either side of said transducer, characterized in that the two arrays of reflectors exhibit nonsymmetric configurations with respect to the central axis of said central transducer. The introduction of an asymmetry makes it possible to strongly attenuate the parasitic resonances which may appear when the resonators are produced notably on piezoelectric substrates of quartz type or any other material and cut with propagation axes for which there exists a natural directivity (LiTaO3, LiNbO3, langasite, GaPO4, LiB4O7, KNbO3, etc.).

Abstract: The invention relates to a surface acoustic wave resonator produced on a cut substrate with propagation axes for which a nonzero directivity exists and comprising at least one central transducer (Tc) exhibiting a central axis, a first array of reflectors (R1) and a second array of reflectors (R2), said arrays being situated on either side of said transducer, characterized in that the two arrays of reflectors exhibit nonsymmetric configurations with respect to the central axis of said central transducer. The introduction of an asymmetry makes it possible to strongly attenuate the parasitic resonances which may appear when the resonators are produced notably on piezoelectric substrates of quartz type or any other material and cut with propagation axes for which there exists a natural directivity (LiTaO3, LiNbO3, langasite, GaPO4, LiB407, KNbO3, etc.

Abstract: The invention relates to a remotely interrogable SAW (surface acoustic wave) temperature sensor comprising. At least two resonators (T1, saw, T2, saw) have transducers having interdigitated electrodes connected to control buses of design such that they have different characteristic operating frequencies. A first resonator has a first surface acoustic wave propagation direction, parallel to one of the axes of the substrate, and a second resonator has a surface acoustic wave propagation direction making a nonzero angle (?) with the propagation direction of the first resonator. The control buses of the second transducer are inclined at a nonzero angle (?) to the normal to the interdigitated electrodes of the second transducer so as to compensate for the power flow divergence of the acoustic waves along the second transducer.

Abstract: The invention relates to a remotely interrogable SAW (surface acoustic wave) temperature sensor comprising, on the surface of a quartz substrate cut along the direction Y? making an angle ? with the direction Y, at least two resonators (T1,SAW, T2,SAW) comprising transducers consisting of interdigitated electrodes connected to control buses of design such that they have different characteristic operating frequencies; and a first resonator having a first surface acoustic wave propagation direction, parallel to one of the axes of the substrate, and a second resonator having a surface acoustic wave propagation direction making a nonzero angle (0) with the propagation direction of the first resonator, characterized in that the control buses of the second transducer are inclined at a nonzero angle (?) to the normal to the interdigitated electrodes of said second transducer so as to compensate for the power flow divergence of the acoustic waves relative to the direction of propagation of the surface acoustic waves

Abstract: The invention relates to interfaces acoutics wave components made of lithium tantalate. Two substrate make up the filter have the same cut and the same crystal orientation, the invention gives the best cut angles in particular for optimizing the electromechanical coupling coefficient that determines the final performance characteristics of the component produced. Curves giving the variations of the coupling coefficient an the attenuation as a function of the cut angles and of the direction of propagation are provided. The values of the main acoustic characteristics of the component for these optimum cut angles are also given. The application of this type of device are, on the on hand, uses as a passive component such a resonator or a filter or a delay line, or as an integrated device, either in a measurement chain or in any array of devices operating according to the principle of recognition of the device by a phase code.

Abstract: The invention relates to interface acoustic wave components made of lithium tantalate. In the case in which the two substrates making up the filter have the same cut and the same crystal orientation, the invention gives the best cut angles in particular for optimizing the electromechanical coupling coefficient that determines the final performance characteristics of the component produced. Curves giving the variations of the coupling coefficient and the attenuation as a function of the cut angles and of the direction of propagation are provided. The values of the main acoustic characteristics of the component for these optimum cut angles are also given. The applications of this type of device are, on the one hand, uses as a passive component such a resonator or a filter or a delay line, or as an integrated device, either in a measurement chain or in an array of devices operating according to the principle of recognition of the device by a phase code.