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    • 专利摘要:
    An electro-optical transducer (T) comprising: - a section of optical fiber (11) comprising a sensitive area (12) conveying an optical signal representative of an elongation of the sensitive area (12), the section of optical fiber (11) being stretched and extending longitudinally at rest substantially along a longitudinal axis (x), - a piezoelectric actuator (A) comprising at least one piezoelectric assembly comprising a piezoelectric bar (4, 5, 6, 7), the piezoelectric bar extending longitudinally at rest substantially parallel to the longitudinal axis (x), said piezoelectric bar being provided with a pair of electrodes between which the piezoelectric bar is intended to be electrically powered by means of an electrical signal delivered by a sensor, said piezoelectric bar being intended to deform essentially by expansion or contraction of said bar parallel to the longitudinal axis (x) in relation to said bar in response to a variation of the electrical signal and being mechanically coupled to the optical fiber section (11) so that this expansion or contraction of the piezoelectric bar (causes a variation in elongation of the sensitive area (12), the piezoelectric bar is in single crystal and intended to vibrate in 31 or 32 mode.
    公开号:FR3045817A1
    申请号:FR1502606
    申请日:2015-12-16
    公开日:2017-06-23
    发明作者:Raphael Lardat；Francois Xavier Launay
    申请人:Thales SA；
    IPC主号:
    专利说明:

    ELECTRO-OPTICAL TRANSDUCER
    The general field of the invention is that of optical fiber measuring devices for measuring physical quantities and for delivering an optical signal conveyed by an optical fiber representative of the measured physical quantity. It relates more particularly to devices for measuring a physical quantity comprising an electric output physical quantity sensor delivering an electrical signal representative of a measured physical quantity and a piezoelectric electro-optical transducer receiving the electrical signal and making it possible to transform, by piezoelectric effect, the electrical signal in an elongation of a sensitive area of an optical fiber so as to vary a characteristic of an optical signal conveyed by the optical fiber according to the variation of the electrical signal. Generally the sensitive area of the optical fiber is a fiber optic laser. The variation of the elongation of an optical fiber laser has the effect of varying the frequency of an optical signal emitted by the optical fiber laser in response to a pump energy carried by the optical fiber.
    This invention is particularly applicable to hybrid hydrophones of the type comprising an acoustic sensor, generally of the piezoelectric type, for delivering an electrical signal representative of an acoustic pressure to which the sensor is subjected and an electro-optical transducer for transforming the acoustic sensor. electrical signal delivered by the sensor in an optical signal conveyed by the optical fiber representative of the measured acoustic pressure. It concerns, for example, antennas in the form of an elongated object of great length or acoustic barriers which are antennas placed at the bottom of the water which make it possible to monitor the passage of boats, for example most often on approach important areas (ports, oil platforms, wind farms, ...).
    An example of an electro-optical transducer 100 with a piezoelectric actuator is described in the patent application WO 2007/056827. This electro-optical transducer is shown schematically in FIG. 1. It comprises an optical fiber 110 comprising a sensitive area 112 of the fiber laser type. The optical fiber conveys an optical signal representative of the elongation of the sensitive zone along the axis of the fiber in response to a pump energy carried by the optical fiber. The transducer 100 also comprises a piezoelectric actuator comprising two piezoelectric bars 103, 104. Each piezoelectric bar comprises two plus +, minus electrodes - between which the delivered electrical voltages are applied, creating an electric field within the bar, by an acoustic sensor 102 via electric wires f1 +, f1 ", f2 +, f2 'The piezoelectric bars 103, 104 are able to expand and contract freely in the direction of their lengths in response to a variation of the electrical signal Piezoelectric bars 103, 104 are mechanically coupled to the optical fiber 110 so that the expansion or contraction of the piezoelectric bars in the direction of their length results in a variation of elongation of the sensitive area 112 of the optical fiber 110 in the longitudinal axis of the fiber The assembly is integrated in a rigid case 105.
    This type of hybrid hydrophone is particularly advantageous in the field of underwater acoustic antennas which are conventionally made in the form of an elongated object of small diameter. They are also called linear antennas or flutes. An acoustic linear antenna integrates a plurality of hydrophones and is intended to be towed by a marine vessel or connected to a land station by means of a towing cable of great length (which may exceed 1km and reach 10 km). An acoustic antenna of this type is generally part of a measuring device as shown in FIG. 2. The measuring device comprises an acoustic linear antenna 201 towed by a marine building 202 by means of a towing cable 203, a unit power supply 205, to produce energy for powering the equipment included in the antenna, and a processing unit 206, for processing the measurements from the various sensors to detect and possibly locate objects. The feeding unit and the processing unit are deported aboard the marine building 202 or on a land station. A wired link 204 is provided between the acoustic antenna 210 and the treatment and power supply units 205, 206. The transformation of the electrical signals delivered by the acoustic sensors into optical signals carried by an optical fiber makes it possible to transport by the optical fiber 204, the information delivered by the sensors to the processing unit 206 without external electrical energy input and without the need for electrical son. In other words, the transducer provides a function of transporting information from the sensors without the need for electrical energy. It is therefore a compact, cheap and light solution. This solution also makes it possible to multiplex a plurality of hydrophones on the same optical fiber spectrally by configuring the different lasers so that they emit optical signals having distinct respective wavelengths. The processing unit 206 then comprises means for demultiplexing the signals from the respective hydrophones and to deduce the acoustic pressure measurements from the respective hydrophones.
    It is possible to sum the measurements coming from several acoustic sensors by arranging them in parallel and / or in series and by connecting them to the same electro-optical transducer, which makes it possible to reduce the number of optical fibers necessary for the transport of information. The cost of the measuring device is thus reduced. Moreover, a piezoelectric actuator requires a power supply of very low power to transform a variation of an electrical signal into a variation of elongation of an optical fiber. The electrical power level of an electrical signal delivered by a piezoelectric acoustic sensor subjected to a low amplitude pressure wave (of the order of 45 dB pPa) is sufficient to operate the actuator. Thus, the supply of electrical energy from another source of electrical energy is not necessary. The acoustic sensors operate as voltage sources proportional to the pressure to be measured, and this voltage source is read and transformed into an elongation of the optical fiber, all without input of any electrical power source. In other words, the transducer provides a function of reading the measurements from the sensors without the need for electrical energy. Furthermore, the amplification and digitization of sensor output signals that would require external energy input are not necessary.
    In the solution shown in FIG. 1, the electromechanical coupling of each piezoelectric bar is longitudinal. In other words, each piezoelectric bar is intended to vibrate in a longitudinal vibration mode also called mode 33. The transducer capacity in low frequency approximation is given by the following formula: c "= 2" 2 | 4 [1] where n is the number of sections connected in parallel on each piezoelectric bar, where L is the length of the piezoelectric bars, ε33 the dielectric coefficient and A is the section of the piezoelectric bars in a plane perpendicular to their length. The capacity of the transducer is expressed in Farad.
    In order to increase the electro-optical sensitivity of the hydrophones, that is to say the laser frequency variation as a function of the variation of the acoustic pressure (expressed in Hz / Pa), the transponder capacity must be close to that of the sensor (for example hydrophone) to which it is electrically connected. For this purpose, it is necessary, for a predetermined length L, to increase the number n of sections connected in parallel along a piezoelectric bar. This involves dividing each bar into a plurality of sections connected to the sensor by means of a pair of electrical wires and a dedicated pair of electrodes. However, this solution has a number of disadvantages. The multiplication of the number of electrical wires and electrodes leads to a loss in terms of simplicity of architecture and manufacturing.
    An object of the invention is to overcome at least one of the aforementioned drawbacks. For this purpose, the invention has for an electro-optical transducer on transforming an electrical signal delivered by a physical measurement sensor into an optical signal, said electro-optical transducer comprising: an optical fiber comprising an optical fiber section comprising a sensitive area, the optical fiber carrying said optical signal, said optical signal being representative of an elongation of the sensitive area, the optical fiber section being stretched and extending longitudinally at rest substantially along a longitudinal axis, - a piezoelectric actuator comprising at least one piezoelectric assembly comprising a piezoelectric bar, the piezoelectric bar extending longitudinally at rest substantially parallel to the longitudinal axis, said piezoelectric bar being provided with a pair of electrodes between which the piezoelectric bar is intended to be electrically powered at by means of the electrical signal, said piezoelectric bar being intended to deform essentially by expansion or contraction of said bar parallel to the longitudinal axis in response to a variation of the electrical signal and being mechanically coupled to the optical fiber section so that this expansion or contraction of the piezoelectric bar causes a variation of elongation of the sensitive area, the piezoelectric bar is single crystal and is intended to vibrate in 31 or 32 mode.
    The transducer advantageously has at least one of the following characteristics taken alone or in combination: the transducer comprises a housing enclosing said actuator, said section of optical fiber, the piezoelectric bar comprising a mobile end able to move relative to the housing during said expansion or contraction of the piezoelectric bar substantially parallel to the longitudinal direction, said piezoelectric actuator comprising a coupling device for mechanically coupling the movable end to the optical fiber section, said coupling device comprising a carriage attached to a portion of the section optical fiber and being able to move in translation relative to the housing along the longitudinal axis, said coupling device further comprising a connecting member for connecting the carriage to a junction zone integral with the housing, the body of bond being adapted to allow translation of the carriage relative to the housing in the axial direction but to prevent significant movement of the carriage relative to the housing in a plane perpendicular to the axial direction; - The piezoelectric bar comprises a so-called fixed end, fixed relative to the housing; - The connecting member comprises at least one flexion plate extending, at rest, in a plane substantially perpendicular to the longitudinal axis and connecting the carriage to a joint junction zone of the housing; the blade is in symmetry of revolution about the axis, the transducer comprises two blades extending, at rest, in respective distinct planes substantially perpendicular to the longitudinal axis; the transducer comprises a housing enclosing the actuator; piezoelectric actuator and the optical fiber section, said piezoelectric actuator comprises a plurality of piezoelectric assemblies arranged so as to form at least one so-called longitudinal pair of two piezoelectric assemblies whose piezoelectric bars each comprise a fixed end relative to the housing and a movable end adapted to move relative to the housing under the effect of an expansion or contraction of said piezoelectric bar, said piezoelectric bars of the two piezoelectric assemblies of the longitudinal pair being aligned along an axis substantially parallel to the longitudinal axis and their ends mobile moved ant in the opposite direction under the effect of an expansion of said bars or under the effect of a contraction of said piezoelectric bars parallel to the longitudinal axis, the portions of the fiber section integral movable ends of said piezoelectric bars surrounding the sensitive area the fixed ends of the piezoelectric bars of the two piezoelectric assemblies of the longitudinal pair are positioned facing each other; the piezoelectric actuator has a first plane of symmetry perpendicular to the axis, the transducer comprises a housing enclosing the piezoelectric actuator and the optical fiber section, said piezoelectric actuator comprises a plurality of piezoelectric assemblies arranged so as to form at least one transverse group of a plurality of piezoelectric assemblies whose piezoelectric bars each comprise a fixed end relative to the housing and a movable end able to move relative to the housing under the effect of an expansion or a contraction of said piezoelectric bar substantially parallel to the longitudinal axis, said piezoelectric bars of the piezoelectric assemblies comprising at least one transverse pair of piezoelectric assemblies whose piezoelectric bars are situated on the one hand and on the other hand respectively on the longitudinal axis n a direction perpendicular to the longitudinal axis, being integral with the same portion of the optical fiber section and moving in the same direction under the effect of an expansion of said piezoelectric bars or under the effect of a contraction of said piezoelectric bars parallel to the longitudinal axis, the transducer comprises four piezoelectric assemblies forming two longitudinal pairs and two transverse groups, each transverse group each comprising a transverse torque, the piezoelectric actuator has two perpendicular planes perpendicular to each other; other and containing the axis. the carriage and / or the junction zone and / or the housing are made of a material having a thermal expansion coefficient of less than 10 × 10 -6 / K -1 at 15 ° C. and at atmospheric pressure. a device for measuring a physical quantity comprising an electroacoustic transducer according to any one of the preceding claims, a sensor adapted to deliver the electrical signal, the electrical signal being representative of a physical quantity measured by said sensor, said sensor being electrically coupled to said bar so as to electrically supply said piezoelectric bar by means of the electric signal.
    Advantageously, the device comprises a plurality of piezoelectric assemblies whose respective piezoelectric bars are coupled to said sensor so that the piezoelectric bars simultaneously expand or contract simultaneously.
    Advantageously, the sensor comprises a plurality of sensors connected in series and / or in parallel.
    The proposed solution allows a transducer of high capacity while maintaining a high electro-optical sensitivity and ease of manufacture of the measuring device. Other features and advantages of the invention will appear on reading the detailed description which follows, given by way of nonlimiting example and with reference to the appended drawings in which: FIG. 1 already described represents a hybrid hydrophone comprising a Electro-optical transducer according to the prior art, - Figure 2 already described schematically represents a measuring device comprising a linear acoustic antenna, - Figure 3 schematically shows the measuring device according to the invention, - Figure 4a shows schematically in cut a coupling device according to the invention at rest, Figure 4b shows schematically in perspective a coupling device according to the invention, Figure 4c schematically shows the coupling device of Figure 4a after expansion of piezoelectric bars, - the figure 5 schematically represents a detail of a portion of the FIG. re 3 surrounded in solid line C, From one figure to another, the same elements are identified by the same references. The invention relates to an electro-optical transducer for transforming an electrical signal, generated at the output of an electrical output sensor in response to a physical quantity, into an optical signal conveyed in an optical fiber, representative of the electrical signal and therefore the measured physical magnitude. By an electrical output sensor is meant a sensor for measuring a physical quantity and delivering an electrical signal representative of the measured physical quantity.
    The electro-optical transducer comprises a piezoelectric actuator, comprising at least one piezoelectric rod made of piezoelectric material, making it possible to transform an electrical signal into an optical signal conveyed by an optical fiber by acting on the elongation of a sensitive zone of the fiber optical so as to vary accordingly a characteristic of an optical signal carried by the optical fiber. The optical signal has a representative characteristic of the electrical signal itself representative of the measured physical quantity. The invention also relates to a measuring device for measuring a physical quantity comprising a sensor for measuring the physical quantity and for delivering an electrical signal representative of the measured physical quantity and an electro-optical transducer according to the invention submitted to said auditory electrical signal so that the transducer transforms the electrical signal into an optical signal conveyed by the optical fiber representative of said electrical signal.
    This invention particularly relates to hybrid hydrophones of the type comprising a sensor comprising at least one sensor for converting an acoustic pressure into an electrical signal. The invention is not limited, of course, to hydrophones. It relates to any measuring device comprising a physical quantity sensor for delivering an electrical signal representative of a physical quantity. The sensor may for example be, non-exhaustively, a heading sensor, a pressure sensor, an acceleration sensor, a sensor immersion, temperature, a radio frequency antenna. The output of this sensor can be analog or digital.
    The sensor may comprise a single sensor or a plurality of sensors arranged in series and / or in parallel or a series / parallel combination. The set of at least one sensor delivers a first electrical signal. The set of at least one sensor can be directly connected to the electro-optical transducer, the first electrical signal is then the electrical signal delivered by the sensor. The sensor may comprise a filter interposed between the assembly of at least one sensor and the electro-optical transducer. The electrical signal delivered by the sensor is then an electrical signal obtained by filtering the first electrical signal. The electro-optical transducer is naturally high so a filter is not essential to filter the continuous.
    The electrical signal is a voltage representative of the physical quantity. The electrical signal makes it possible to electrically power the piezoelectric rod (s), that is to say to apply an electric field to the piezoelectric rod (s) between the electrodes.
    Figure 3 schematically shows a measuring device according to the invention. This measuring device comprises a sensor C as defined above and an electro-optical transducer T according to the invention comprising an optical fiber 10. The electro-optical transducer T is electrically coupled to the sensor C so as to transform an electric signal delivered by the sensor C and applied to the electro-optical transducer T in an optical signal, carried by an optical fiber 10, representative of the electrical signal. More specifically, the electro-optical transducer transforms, by piezoelectric effect, a variation of an electrical signal delivered by the sensor into a variation of an elongation of a sensitive area 12 of the optical fiber. The optical fiber 10 conveys an optical signal having a characteristic representative of an elongation of the sensitive area 12 in the direction of the length of the optical fiber 10. The variation of elongation of the sensitive area 12 consequently results in a variation the characteristic of the optical signal conveyed by the fiber. The characteristic of the optical signal is representative of the elongation of the sensitive area 12 the optical fiber 10 itself representative of the electrical signal representative of the physical quantity.
    The characteristic of the optical signal that varies with the elongation of the sensitive area is for example a wavelength or a phase of a signal.
    The sensitive zone 12 is for example of the fiber laser type. The fiber lasers comprise a Bragg grating inscribed in the sensitive zone 12 of the optical fiber 10. The fiber laser emits an optical signal having a wavelength representative of the elongation of the sensitive zone 12 in the direction of the optical fiber. As a variant, the transducer is configured so as to transform a variation of an electrical signal into a variation of an elongation of the sensitive zone of an optical fiber resulting in a variation of the phase of the optical fiber. first optical signal. In this case, there is no Bragg grating inscribed in the optical fiber.
    The electro-optical transducer comprises a piezoelectric actuator A. The piezoelectric actuator A makes it possible to transform, by piezoelectric effect, an electrical signal delivered by the sensor C into an elongation of the sensitive zone 12 representative of the electrical signal. For this purpose, the piezoelectric actuator A comprises a plurality of piezoelectric assemblies each comprising a piezoelectric bar 4, 5, 6, 7 made of piezoelectric material, electrodes and associated electrical wires. In the embodiment of the figures, the actuator A comprises four piezoelectric bars. This embodiment is not limiting, the actuator may alternatively comprise a piezoelectric bar or a plurality of piezoelectric bars in number other than four.
    Each piezoelectric assembly comprises a pair of electric wires f /, ff, f2 +, fi, fz, fa ", f4 +, U making it possible to electrically couple one of the piezoelectric bars 4, 5, 6, 7 to the sensor C so as to electrically power the piezoelectric bar 4, 5, 6, 7 by means of the electrical signal delivered by the sensor C. For this purpose, as shown in FIG. 5, the piezoelectric bars are provided at their conductive electrode surfaces e +, e- forming part of The electrodes fitted to the respective bars are connected to the respective pairs of electric wires The direction and direction of the electric field E to which the different piezoelectric bars are subjected are represented by arrows in FIG. clarity, the electrodes are not shown in Figures 3 and 4.
    As can be seen in the enlargement of FIG. 3, the piezoelectric bars 4, 5, 6, 7 are coupled to an optical fiber section 11 comprising the sensitive zone 12. The optical fiber section 11 is stretched and extends longitudinally rest along a longitudinal axis x. The optical fiber section 11 is prestressed so as to remain in tension regardless of the movements of the transducer and the value of the electrical signal generated by the sensor under the effect of the physical quantity in the operating zone of the sensor.
    At rest, the piezoelectric bars 4, 5, 6, 7 extend longitudinally in respective directions substantially parallel to the longitudinal axis x. In the present patent application is meant that the piezoelectric bars and the optical fiber section are at rest when the bars are not electrically powered and when the transducer is not subject to any acceleration. By substantially parallel, it is meant that the longitudinal axes of the bars have low maximum inclinations that can come from manufacturing tolerances. This allows better cooperation between the bars and limit the sensitivity of the transducer to transverse accelerations.
    Each piezoelectric bar 4, 5, 6, 7 is arranged so as to be deformed in response to a variation of the electrical signal, that is to say in response to a variation of the electric field to which it is subjected, essentially by dilation or contraction in the direction of its length parallel to the longitudinal axis. In other words, the bars work essentially in tension-compression parallel to the x-axis. This is obtained by the mechanical coupling of each piezoelectric bar with respect to a rigid housing 20 enclosing the actuator A and the section 11 of optical fiber to which it is coupled. For each bar, the longitudinal faces of the bar (faces parallel to the x axis) which are parallel to each other are intended to deform in the same manner under the effect of a variation of the electric field E. Each bar 4, 5 , 6, 7 is mechanically coupled to the section of optical fiber 11 so that the expansion and contraction of the electric bar 4, 5, 6, 7 parallel to the x axis causes variations in elongation of the section 11 and consequently variations of elongation of the sensitive zone 12. More precisely, the expansion and contraction of the electric bar 4, 5, 6, 7 parallel to the axis x longitudinally cause deformation of the section 11 essentially along the x axis and more precisely a variation of elongation of this section along the x axis.
    The piezoelectric bars 4, 5, 6, 7 are parallelepipedic. Advantageously, the bars are rectangular parallelepipeds. These bars have a length Lp (direction of the bars along the x axis) and a thickness h (distance between the electrodes).
    In the electro-optical transducer T according to the invention, each piezoelectric bar 4, 5, 6, 7 is in single crystal. The use of single crystals makes it possible to obtain a significant elongation for a given electric field which makes it possible to obtain a transducer having a good sensitivity. It is for example PZN-PT or PMN-PT. Furthermore, the bars 4, 5, 6, 7 are intended to vibrate in transverse mode also called mode 31 or 32. In other words, the electromechanical coupling of the piezoelectric bar is transverse. This means that the electric wires fi +, fr, i2 +, h ', f3 +, f3_, U +, W are connected to the piezoelectric bars so as to electrically supply the material of the piezoelectric bar, that is to say to submit the piezoelectric bar to an electric field along an axis perpendicular or substantially perpendicular to its main axis of deformation. The main axis of deformation is the axis in which the bars deform mainly under the effect of the electric field applied by means of the electric wires. The main deformation axis is parallel or substantially parallel to the x axis. In the example shown in Figure 3, the main axis of deformation is the axis 1 in an orthogonal trihedron 1,2,3 linked to the bar and conventionally used for piezoelectric materials. The bars operate in mode 31.
    Each piezoelectric bar comprises a first electrode e + and a second electrode e - arranged on respective faces of the piezoelectric bar. These faces are defined by the main axis of deformation of the bars and by an axis perpendicular to the axis of application of the electric field E. On the embodiment of Figure 3, the electrodes extend in the plane 1, 2.
    The modes 31 and 32 have the same merit factor as the mode 33 (longitudinal mode) but have the advantage of making it possible to obtain an electro-optical transducer having a capacity much greater than that of a transducer according to the prior art. while maintaining high electro-optical sensitivity and ease of manufacture.
    Indeed, the electro-optical capacitance Ca of the transducer, expressed in Farads, according to the invention in low frequency approximation is given by the following formula:
    [2] Where Lp is the length of the piezoelectric bar along the axis 1 for the mode 31 and along the axis 2 for the mode 32, h the thickness of the piezoelectric bars along the axis 3 that is to say the distance between the electrodes, b the width of the bars along the axis 2 (mode 31) or along the axis 1 (mode 32).
    The capacitance Ca of the transducer according to the invention is much greater than the capacitance Caa 'that would present a transducer of the type of that of FIG. 1 which would have bars of the same dimensions with a single section (n = 1) of length Lp and the same dielectric coefficient. Indeed, according to formula 1, this capacity would be given by the following formula:
    [3]
    Therefore according to the formulas [2] and [3]: CJCJ = L2p / h2 "
    Indeed, the thickness h is much smaller than the length Lp.
    The capacity of the transducer according to the invention is therefore very important for a reduced number of connections of electrical wires. Therefore, the transducer according to the invention has good electro-optical sensitivity and is easy to manufacture. Furthermore, the capacity of the transducer is easily adjustable by adjusting the length of the piezoelectric bars.
    Typically, the transducer according to the invention may have a capacity greater than 1 nF and a sensitivity greater than 160 dB Hz / V. A hybrid hydrophone integrating a transducer according to the invention thus makes it possible to read very small variations in acoustic pressure.
    The electro-optical sensitivity Su of the transducer according to the invention, expressed in dB, is given by the following formula obtained by analytical modeling:
    with fi the frequency of the laser, d3i the piezoelectric coefficient and Lf the stretched fiber length.
    As shown in Figure 3, the transducer T according to the invention comprises a housing 20 enclosing the piezoelectric actuator and the optical fiber section 11 on which the actuator acts. This protects the piezoelectric actuator. Advantageously, the housing is rigid which makes the transducer insensitive to the pressure exerted by a liquid in which the housing is immersed and to obtain good resistance to immersion. Rigid means that the housing is dimensionally stable throughout the range of operating pressures of the transducer. The rigid housing is attached to the optical fiber on either side of the section 11 of optical fiber. The case is hermetically sealed.
    The housing 20 comprises a rigid central portion in the form of a rigid tube 21, end portions comprising rigid plugs 22 and holding pieces 23 resting on the tube 21 and integral with the ends of the section 11. The plugs and the tube could alternatively form a single piece. The section of optical fiber 11 to which the actuator is coupled is enclosed within the housing 20. The tube 21 is advantageously symmetrical about the x axis.
    In the embodiment of the figures, the piezoelectric actuator comprises four piezoelectric bars: a first 4, a second 5, a third 6 and a fourth 7 piezoelectric bar. The piezoelectric actuator comprises coupling devices 30 for mechanically coupling the piezoelectric bars to the section of optical fiber 11 so that the deformation of the bars under the effect of a variation of the electrical signal causes a variation in elongation of the fiber optical.
    Each piezoelectric bar 4, 5, 6, 7 extends longitudinally from a first end to a second end. The first end, called mobile end El, is intended to move substantially parallel to the x axis relative to the housing 20 under the effect of a variation of the electrical signal, that is to say under the effect of deformation of the piezoelectric bar along the x axis. Each movable end E1 is secured to a portion 11a, 11b of the optical fiber section 11. The second end, called fixed end Ef, is fixed relative to the housing 20. For the sake of clarity, the ends E1 and Ef are referenced only for the second bar 5 in FIG. 3. During the expansion or contraction of the piezoelectric bars 4, 5, 6, 7, the fixed ends Ef remain fixed with respect to the housing 20 and the movable ends E1 move relative to the ends fixed Ef respectively in the direction of the length of the piezoelectric bars 4, 5, 6, 7, that is to say substantially parallel to the direction x.
    In the embodiment of FIG. 3, the different piezoelectric assemblies of the piezoelectric actuator A are arranged so as to form two groups of longitudinal piezoelectric assemblies. A first longitudinal group comprises the piezoelectric bars 4 and 6. These bars 4 and 6 are aligned along an axis substantially parallel to the axis of the section 11, that is to say to the longitudinal axis x. The second longitudinal group comprises the two piezoelectric bars 5 and 7. These bars 5 and 7 are aligned along another axis substantially parallel to the x axis. Consequently each longitudinal group is a longitudinal pair and the two bars of each of the longitudinal pairs are arranged side by side along an axis substantially parallel to the x axis and extend longitudinally substantially parallel to the same axis x. The movable ends E1 of the two bars 4 and 6 or 5 and 7 of each of the longitudinal groups move in the opposite direction under the effect of an expansion of the bars or under the effect of a contraction of the bars parallel to the longitudinal direction x. The portions 11a, 11b of the fiber section 11 integral with the movable ends E1 of the piezoelectric bars of each of the longitudinal groups surround the sensitive zone 12. In a variant, the device according to the invention comprises a single longitudinal group or more than two longitudinal groups .
    Advantageously, all the piezoelectric bars are arranged and electrically powered by means of the electrical signal so as to generate either the expansion of all the piezoelectric bars simultaneously or the contraction of all the piezoelectric bars simultaneously. The piezoelectric bars are advantageously supplied in parallel.
    In the embodiment of Figure 3, the two fixed ends Ef of two bars 4 and 6 or 5 and 7 aligned in a direction substantially parallel to the axis x are located opposite one another. In other words, the two fixed ends Ef of the two bars are the adjacent ends of the two bars. The distance separating the fixed ends of the two bars is less than the distance separating the movable ends E1 of the two bars.
    Therefore, when the bars 4, 5, 6, 7 expand under the effect of a variation of the electrical signal, the elongation of the sensitive area increases. This acts on the elongation of a portion of the optical fiber of great length during the expansion or retraction of the bars which allows not to disturb the operation of the laser.
    In the example of Figures 3 and 5, the fixed ends Ef of the bars 4, 5, 6, 7 are fixed to a support 40 secured to the housing 20 interposed between the bars 4, 6 of the first pair of piezoelectric assemblies and between the piezoelectric bars 5, 7 of the second pair of piezoelectric assemblies. Alternatively, the fixed ends Ef are integral with the housing 20 or separate supports. The support 40 does not have a shape limited to the representation of FIG.
    As a variant, the movable ends E1 of the bars aligned along the same axis are arranged facing one another. This acts on the elongation of a portion of the optical fiber of short length during the expansion or retraction of the bars. Advantageously, the piezoelectric actuator A has a first plane P of symmetry perpendicular to the longitudinal axis x. In other words, the piezoelectric bars aligned along the same axis are identical, that is to say are made of the same material, have the same dimensions and the same orientation about the axis in which they are aligned and are coupled to the optical fiber by means of identical coupling devices. This characteristic makes it possible to limit the sensitivity of the transducer to acceleration in the axial direction (parallel to the x-axis). Indeed, the two bars aligned along the same axis in the axial direction have the same stiffness and deform in a contrary manner under the effect of axial acceleration which avoids a variation of elongation of the sensitive area 12 .
    In a variant, the piezoelectric actuator comprises a single piezoelectric bar with an axis parallel to the longitudinal axis x. In this case, the piezoelectric bar comprises two x-axis-moving ends which are each coupled to the optical fiber by means of a coupling device 30.
    Advantageously, as in the case of FIG. 3, the piezoelectric assemblies of the actuator are arranged so as to form at least one group of transverse piezoelectric assemblies of piezoelectric assemblies whose piezoelectric bars 4 and 5 (or respectively 6 and 7) each comprise a fixed end Ef with respect to the housing 20 and a mobile end El able to move relative to the housing 20 under the effect of an expansion or a contraction of said piezoelectric bar parallel to the x-axis that is to say under the effect of a variation of the electrical supply signal. Each transverse group comprises at least one transverse pair of piezoelectric assemblies, the piezoelectric bars of each transverse group, that is to say the bars 4 and 5 or respectively the bars 6 and 7 are located on each side and respectively part of the longitudinal axis x in a direction perpendicular to the longitudinal axis x. The piezoelectric bars 4 and 5, or respectively 6 and 7, of each transverse pair are integral with the same portion 11a, respectively 11b, of the optical fiber section 11 and move in the same direction under the effect of a dilation of the bars or under the effect of a contraction of said piezoelectric bars substantially parallel to the longitudinal axis, that is to say under the effect of a variation of the electrical signal by subjecting the bars to electric fields inducing a simultaneous dilation of all the bars or a simultaneous contraction of all the bars.
    In the embodiment of FIG. 3, the device comprises two transverse groups. Each of the transverse groups comprises two piezoelectric assemblies, that is to say two piezoelectric bars bars 4 and 5 and respectively 6 and 7. The movable ends of the bars of two different transverse groups move in the opposite direction under the effect of a dilation of the bars parallel to the x axis.
    Advantageously, the piezoelectric actuator has two other planes of symmetry, which are the planes orthogonal to the plane P of FIG. 3, and which comprise the axis x. This characteristic makes it possible to limit the sensitivity of the transducer to accelerations according to the transverse directions 1 and 2
    Each transverse group may comprise more than two piezoelectric assemblies. The piezoelectric bars of a transverse group have for example longitudinal axes substantially parallel to the axis and regularly distributed over a circle perpendicular to the x axis.
    FIGS. 4a and 4b schematically represent a section in the plane of the sheet of FIG. 3 (FIG. 4a) and a perspective view of the section of FIG. 4a (FIG. 4b) of a coupling device 30 for coupling mechanically at least one piezoelectric bar to said optical fiber so as to transform an expansion or contraction of each piezoelectric rod to which it is connected in a variation of elongation of the optical fiber. The coupling device 30 makes it possible to couple the mobile end E1 of at least one bar 4, 5, 6, 7 to the section 11 of the optical fiber 12.
    In the embodiment of FIGS. 3 and 4, the actuator comprises two coupling devices 30. The optical fiber section 11 extends between the two coupling devices 30 and is prestressed so as to be maintained in tension between the two devices of FIG. coupling 30.
    Each coupling device 30 makes it possible to couple the mobile end E1 of two bars 4, 5 or 6.7 to the optical fiber section 11.
    The coupling device 30 could be glue or any other means of attachment.
    In the preferred embodiment, the coupling device 30 comprises a carriage 31 adapted to move in translation relative to the rigid housing in the axial direction x. The carriage 31 is integral with the optical fiber 11 and more precisely with a portion of the optical fiber 11. As can be seen in FIG. 3, each movable end E1 of a bar 4, 5, 6, 7 is attached to a carriage 31 of a coupling device 30.
    In the embodiment of FIGS. 3 and 4, the ends of two piezoelectric bars 4, 5 or 6, 7 are fixed to each carriage 31.
    The coupling device 30 comprises a connecting member 32 for connecting the carriage 31 to the rigid housing 20. In the embodiment of FIGS. 3 and 4a, 4b, 4c, the connecting member 32 connects the carriage 31 to a zone of junction 35 belonging to the coupling device and fixed relative to the housing 20. Alternatively, the connecting member 32 connects the carriage 31 directly to the housing 20 and more particularly to the cylindrical tube 21. The junction zone 35 then belongs to the housing 20 .
    Advantageously, the connecting member 32 is designed to allow a translation of the carriage 31 relative to the housing 20 along the longitudinal axis x but to prevent any significant movement of the carriage 31 relative to the housing 20 in the radial directions relative to the x axis. In other words, the connecting member has an axial stiffness (parallel to the x axis) less than the radial stiffness (perpendicular to the x axis).
    When the electrical signal varies, each piezoelectric bar 4, 5, 6, 7 expands or contracts parallel to the axial direction. With its mobile end E1 attached to a carriage 31, this deformation of a piezoelectric bar 4, 5, 6, 7 tends to cause the carriage 31 to move parallel to the axial direction x as represented by the arrows in FIG. 3. Being given that the connecting member 32 allows a translation of the carriage 31 relative to the housing 20, the carriage 31 moves parallel to the axial direction x relative to the housing 20 carrying with it the portion of the optical fiber 11 to which it is fixed which has the effect of varying the elongation of the sensitive area 12 of the optical fiber 11. The low axial stiffness (that is to say in the x direction) of the connecting member 32 can limit degradation of the electro-acoustic sensitivity of the transducer.
    When the transducer is subjected to transverse acceleration, the piezoelectric bars flex. The high stiffness of the connecting member 32 in a direction perpendicular to the axial direction x avoids the movement of the fiber portion 11a, 11b to which the coupling device 30 is fixed in a radial plane. The presented solution therefore makes it possible to reduce the sensitivity of the transponder to acceleration.
    Indeed, lasers with fiber laser cavities used in this solution are extremely sensitive to any deformation. The solution limits the variation of elongation of the fiber induced by the accelerations seen by the transponder while maintaining a high electro-optical sensitivity which is given by a large axial deformation of the fiber by excitation volt to the good of the electronic transponder. optical. In other words, the presented solution selects the electrically excited deformation mode while minimizing the deformation modes induced in directions perpendicular to the axis of the fiber laser. The connecting device 32 also makes it possible to reduce the effect of small manufacturing defects, in particular the lack of parallelism between the longitudinal axes of the bars and the x-axis, by allowing the deformation of the optical fiber only in the axial direction.
    Advantageously, the connecting member 32 is designed to allow a translation of the carriage 31 relative to the housing 20 parallel to the x-axis by preventing any significant movement of the carriage 31 relative to the housing 20 in any direction in a plane perpendicular to the longitudinal axis x. For this purpose, the connecting member is for example symmetrical of revolution about the longitudinal axis x. For this purpose, the connecting member comprises at least one bending member 33, 34 having a high stiffness in a radial direction. This great stiffness does not allow the movement of the carriage in the radial direction. The connecting piece 33, 34 is also very narrow, in the axial direction, compared to its dimension in the radial direction, so as to have a low stiffness in the axial direction. This low stiffness allows a movement of the carriage 31 relative to the housing 20 in the axial direction. It makes it possible not to degrade the sensitivity of the transducer too much.
    In the embodiment shown in Figures 4a, 4b and 4c, the connecting member 32 comprises two bending plates 33, 34 extending, at rest, in respective planes substantially perpendicular to the longitudinal axis x. They connect the carriage 31 to the junction zone 35 integral with the housing. The flexion blades 33, 34 have a high radial stiffness and a low stiffness in the axial direction. This embodiment makes it possible to prohibit the rotations of the carriage (and consequently of the optical fiber) around axes perpendicular to the x-axis.
    Advantageously, the flexion plates 33, 34 are symmetrical about the x axis.
    Alternatively, the connecting member 32 comprises a single bending blade 33. In another variant, the bending blades are replaced by one or more O-rings connecting the carriage 31 and the joining zone 35 or by any other means presenting a significant stiffness in the radial direction and weak in the radial direction.
    In the embodiment of FIGS. 4a, 4b, 4c, the coupling device comprises a cylindrical tubular carriage 31 integral with a portion of the section of the optical fiber 11. The carriage 31 is symmetrical about the x axis. The carriage 31 is traversed by the optical fiber 10 which extends longitudinally along the x axis. The two flexion blades 33, 34 are flat rings, ie discs having a central opening through which the optical fiber passes through the carriage 31. The flexion blades 33, 34 are symmetrical about the axis of rotation. x. These blades 33, 34 in the form of flat rings surround the carriage 31. The blades 33, 34 extend radially from the carriage 31 to the junction zone 35. They are for example fixed at the respective longitudinal ends of the trolley 31. The longitudinal ends of the carriage 31 are the ends of the carriage 31 parallel to the x-axis.
    In the embodiment of FIGS. 3 and 4a, 4b, the junction zone 35 is a tube integral with the rotationally symmetrical housing around the axis of the fiber. The junction zone 35 surrounds the flexion blades 33, 34 and the optical fiber 10. The junction zone 35 has an inside diameter greater than the outside diameter of the carriage 31 so that a space is provided, in the radial direction, between the outer surface of the carriage 31 and the inner surface of the junction zone 35. This allows the blades to deform freely in bending.
    When the bars 4, 5, 6, 7 expand or contract, they exert an axial force on the carriage 31 which causes flexing of the flexible blades 33, 34 thus allowing the carriage 31 to be translated in the axial direction x with respect to the housing as shown in Figure 4c. FIG. 4c represents the form of the coupling device of FIG. 4a after expansion of the bars 6 and 7. The deformation of the assembly formed by the flexible blades 33, 34, the carriage 31 and the junction zone 35 is close to that a double deformable parallelogram.
    The arrangement of the two blades 33, 34 respectively on either side of the carriage 31 in the axial direction, or more generally spaced in the axial direction, makes it impossible for the carriage 31 to rotate about the x axis with respect to the 20. This avoids the parasitic variations of the optical signal due to radial accelerations.
    The bending blades can be full or perforated.
    In the embodiment shown in FIGS. 3 and 5, the actuator comprises four piezoelectric bars 4, 5, 6, 7 forming two longitudinal pairs of piezoelectric assemblies and two transverse pairs of piezoelectric assemblies. The bars are aligned in pairs along respective axes substantially parallel to the x axis. In addition, the actuator has three orthogonal planes of symmetry. This embodiment makes it possible to maintain a high degree of symmetry, which makes it possible to limit the sensitivity of the transducer to accelerations.
    Advantageously, the support 40 and / or the carriage 31 and / or the junction zone 35 are made of a material having a coefficient of thermal expansion (less than 10 × 10 -6 / K -1) at 15 ° C. and at atmospheric pressure. This limits the sensitivity of the device to temperature variations and thus to increase the number of transducers that can be placed in series on the same optical fiber.
    The support 40 is advantageously made of Zerodur whose coefficient of thermal expansion is very low. It could alternatively be made of glass. The carriage 31 is advantageously made of Zerodur. It could alternatively be made of glass. These parts could also be made of titanium with less effective in limiting the sensitivity of the transducer to temperature variations.
    The blades 33, 34 are for example metal parts, for example steel. This material is cheap and very available on the market.
    The housing is for example made of titanium or steel or any other material resistant to pressure.
    The transducer according to the invention has a very wide dynamic. It can measure voltages ranging from the nanovolt to 10V.
    权利要求:
    Claims (16)
    [1" id="c-fr-0001]
    An electro-optical transducer (T) for transforming an electrical signal delivered by a physical measurement sensor (C) into an optical signal, said electro-optical transducer (T) comprising: an optical fiber (10) comprising a section optical fiber (11) comprising a sensitive area (12), the optical fiber (10) conveying said optical signal, said optical signal being representative of an elongation of the sensitive area (12), the optical fiber section (11) being tensioned and extending longitudinally at rest substantially along a longitudinal axis (x), • a piezoelectric actuator (A) comprising at least one piezoelectric assembly comprising a piezoelectric bar (4, 5, 6, 7), the piezoelectric bar (4) , 5, 6, 7) extending longitudinally at rest substantially parallel to the longitudinal axis (x), said piezoelectric bar being provided with a pair of electrodes (e +, e-) between which the piezoelectric bar electrical (4, 5, 6, 7) is intended to be electrically powered by means of the electrical signal, said piezoelectric bar (4, 5, 6, 7) being intended to deform essentially by expansion or contraction of said bar parallel to the longitudinal axis (x) in response to a variation of the electrical signal and being mechanically coupled to the optical fiber section (11) such that this expansion or contraction of the piezoelectric bar (4, 5, 6, 7) causes a variation in elongation of the sensitive zone (12), characterized in that the piezoelectric bar (4, 5, 6, 7) is single crystal and is intended to vibrate in mode 31 or 32.
    [2" id="c-fr-0002]
    2. Electro-optical transducer according to the preceding claim, comprising a housing (20) enclosing said actuator (A), said optical fiber section (11), the piezoelectric bar (4, 5, 6, 7) comprising a movable end ( El) adapted to move relative to the housing (20) during said expansion or contraction of the piezoelectric bar (4, 5, 6, 7) substantially parallel to the longitudinal direction, said piezoelectric actuator (A) comprising a coupling (30) for mechanically coupling the movable end (El) to the optical fiber section (11), said coupling device (30) comprising a carriage (31) attached to a portion of the optical fiber section (11) and being able to move in translation relative to the housing (20) along the longitudinal axis (x), said coupling device (30) further comprising a connecting member (32) for connecting the carriage (31) to a junction area (3 5) integral with the housing (20), the connecting member (32) being designed to allow a translation of the carriage (31) relative to the housing (20) in the axial direction (x) but to prevent any significant movement of the carriage (31) relative to the housing (20) in a plane perpendicular to the axial direction.
    [3" id="c-fr-0003]
    3. Electro-optical transducer according to the preceding claim, wherein the piezoelectric bar comprises a fixed end (Ef), fixed relative to the housing (20).
    [4" id="c-fr-0004]
    4. Electro-optical transducer according to any one of claims 2 to 3, wherein the connecting member (32) comprises at least one flexion plate (33, 34) extending, at rest, in a plane substantially perpendicular to the longitudinal axis (x) and connecting the carriage (31) to a junction zone (35) integral with the housing (20).
    [5" id="c-fr-0005]
    5. Electro-optical transducer according to the preceding claim, wherein the blade (33, 34) is symmetrical of revolution about the axis (x).
    [6" id="c-fr-0006]
    6. electro-optical transducer according to any one of claims 4 to 5, comprising two blades (33, 34) extending, at rest, in respective respective planes substantially perpendicular to the longitudinal axis.
    [7" id="c-fr-0007]
    An electro-optical transducer according to any one of the preceding claims, comprising a housing (20) enclosing the piezoelectric actuator (A) and the optical fiber section (11), said piezoelectric actuator (A) comprises a plurality of piezoelectric assemblies arranged so as to form at least one so-called longitudinal pair of two piezoelectric assemblies whose piezoelectric bars each comprise a fixed end (Ef) with respect to the housing (20) and a movable end (El) able to move relative to the housing (20) under the effect of an expansion or contraction of said piezoelectric bar, said piezoelectric bars of the two piezoelectric assemblies of the longitudinal pair being aligned along an axis substantially parallel to the longitudinal axis (x) and their moving ends (El) moving in the opposite direction under the effect of a dilation of said bars or under the effect a contraction of said piezoelectric bars parallel to the longitudinal axis, the portions of the fiber section (11) integral with the movable ends (El) of said piezoelectric bars surrounding the sensitive area (12).
    [8" id="c-fr-0008]
    8. Electro-optical transducer according to the preceding claim, wherein the fixed ends (Ef) of the piezoelectric bars of the two sets of piezoelectric longitudinal torque are positioned one facing each other.
    [9" id="c-fr-0009]
    An electro-optical transducer according to any one of claims 7 to 8, wherein the piezoelectric actuator (A) has a first plane of symmetry (P) perpendicular to the axis (x).
    [10" id="c-fr-0010]
    A transducer according to any one of the preceding claims, comprising a housing (20) enclosing the piezoelectric actuator (A) and the optical fiber section (11), said piezoelectric actuator (A) comprises a plurality of arranged piezoelectric assemblies. so as to form at least one so-called transverse group of a plurality of piezoelectric assemblies whose piezoelectric bars (4, 5; 6, 7) each comprise a fixed end (Ef) with respect to the housing (20) and a movable end (El) adapted to move relative to the housing (20) under the effect of an expansion or contraction of said piezoelectric bar substantially parallel to the longitudinal axis (x), said piezoelectric bars of the piezoelectric assemblies comprising at least a transverse pair of piezoelectric assemblies whose piezoelectric bars are located on the one hand and on the other hand respectively on the axis lon longitudinal (x) in a direction perpendicular to the longitudinal axis (x), being integral with the same portion of the optical fiber section (11) and moving in the same direction under the effect of an expansion of said piezoelectric bars or under the effect of a contraction of said piezoelectric bars parallel to the longitudinal axis.
    [11" id="c-fr-0011]
    11. Electro-optical transducer according to claim 10 and claim 7, comprising four piezoelectric assemblies forming two longitudinal pairs and two transverse groups, each transverse group each comprising a transverse torque.
    [12" id="c-fr-0012]
    An electro-optical transducer according to any one of the preceding claims, wherein the piezoelectric actuator (A) has two symmetry planes perpendicular to each other and containing the axis (x).
    [13" id="c-fr-0013]
    An electro-optical transducer according to any one of claims 2 to 6 or 7 to 12 as dependent on claim 2, wherein the carriage (31) and / or the junction zone (35) and / or the housing are made of a material having a coefficient of thermal expansion less than 10.10'6 / K "1 at 15 ° C and at atmospheric pressure.
    [14" id="c-fr-0014]
    14. Device for measuring a physical quantity comprising an electroacoustic transducer (T) according to any one of the preceding claims, a sensor (C) capable of delivering the electrical signal, the electrical signal being representative of a physical quantity measured by said sensor, said sensor (C) being electrically coupled to said bar so as to electrically power said piezoelectric bar by means of the electrical signal.
    [15" id="c-fr-0015]
    15. Device for measuring a physical quantity according to the preceding claim, comprising a plurality of piezoelectric assemblies whose respective piezoelectric bars are coupled to said sensor so that the piezoelectric bars simultaneously expand or contract simultaneously.
    [16" id="c-fr-0016]
    16. Measuring device according to any one of claims 14 to 15, wherein the sensor comprises a plurality of sensors connected in series and / or in parallel.
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    同族专利:
    公开号 | 公开日
    CA3008704A1|2017-06-22|
    EP3390989B1|2021-09-01|
    US20190003880A1|2019-01-03|
    FR3045817B1|2018-01-19|
    AU2016372328B2|2021-02-18|
    AU2016372328A1|2018-07-19|
    EP3390989A1|2018-10-24|
    WO2017102767A1|2017-06-22|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR2504285A1|1981-04-15|1982-10-22|Chevron Res|Single mode optical fibre beam modulator - has movable, spatially periodic perturbation using optical grating placed near core|
    US20090135673A1|2005-11-21|2009-05-28|Thales Underwater Systems Pty Limited|Methods, Systems and Apparatus for Measuring Acoustic Pressure|
    US8659211B1|2011-09-26|2014-02-25|Image Acoustics, Inc.|Quad and dual cantilever transduction apparatus|
    US20140175271A1|2012-12-22|2014-06-26|Halliburton Energy Services, Inc.|Remote Sensing Methods and Systems Using Nonlinear Light Conversion and Sense Signal Transformation|WO2019020604A2|2017-07-27|2019-01-31|Thales|Temperature-compensating device and electro-optic transponder implementing such a device|
    CN109374112A|2018-11-20|2019-02-22|浙江大学|Optical-fiber two-dimensional vibrating sensor and preparation method thereof|
    GB2561821B|2017-04-06|2020-02-12|Synaptec Ltd|Multi-phase sensor module, systems and methods|
    CN111399034B|2020-03-31|2021-03-16|武汉理工大学|Hydrophone detection device and method based on low bending loss chirped grating array|
    CN111785004A|2020-07-01|2020-10-16|上海广拓信息技术有限公司|Line patrol information transmission method and system|
    法律状态:
    2016-11-28| PLFP| Fee payment|Year of fee payment: 2 |
    2017-06-23| PLSC| Publication of the preliminary search report|Effective date: 20170623 |
    2017-11-27| PLFP| Fee payment|Year of fee payment: 3 |
    2019-11-28| PLFP| Fee payment|Year of fee payment: 5 |
    2020-11-25| PLFP| Fee payment|Year of fee payment: 6 |
    2021-11-26| PLFP| Fee payment|Year of fee payment: 7 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1502606A|FR3045817B1|2015-12-16|2015-12-16|ELECTRO-OPTICAL TRANSDUCER|
    FR1502606|2015-12-16|FR1502606A| FR3045817B1|2015-12-16|2015-12-16|ELECTRO-OPTICAL TRANSDUCER|
    CA3008704A| CA3008704A1|2015-12-16|2016-12-13|Transducteur electro-optique|
    PCT/EP2016/080860| WO2017102767A1|2015-12-16|2016-12-13|Electro-optical transducer|
    US16/063,194| US20190003880A1|2015-12-16|2016-12-13|Electro-optical transducer|
    AU2016372328A| AU2016372328B2|2015-12-16|2016-12-13|Electro-optical transducer|
    EP16822924.3A| EP3390989B1|2015-12-16|2016-12-13|Electro-optical transducer|
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