FR2538127A1 - Optical quadripole and multipole comprising such quadripoles - Google Patents

Abstract

The present invention relates to an optical quadripole which can be used especially as a coupler for access to an optical serial bus. It comprises four arms A, B, C, D each having means for receiving and/or for transmitting light rays 2 and a return device 3 having two operational states, a first state where it is reflecting and is capable of returning the light between the arm A and the arm B on the one hand, and between the arm C and the arm D on the other hand, and a second state where it allows light to pass between the arm A and the arm D on the one hand, and between the arm B and the arm C on the other hand. The four arms A, B, C, D are coplanar and each arm forms an angle of 90 DEG with the adjacent arms. A coupler for access to a serial bus is produced by connecting the arm A to an optical line L, the arm B to a detector Ri, the arm C to an emitter Ei and by arranging the arm D so that it returns the amplified light signals to a section downstream of the optical line L. A line L'i connects the detector Ri and the emitter Ei in order to produce the said amplified signals.

Description

OPTICAL AND MULTIPOLE QUADRIPOLE
COMPRISING SUCH QUADRIPOLES
The present invention relates to an optical quadrupole capable of being used in particular as an access coupler to a serial bus, and an optical multipole associating such quadrupoles.

 A serial bus access coupler makes it possible to take or inject an optical signal into the line of a serial bus system. The coupler must also guarantee the reliability of the serial bus in the event of a terminal failure by isolating it.

 Access couplers of the prior art generally have two Y-shaped branches for picking up and injecting shunt signals on an optical line constituting the serial bus. In the event of a fault with a detector or a transmitter in one of the access couplers, the online signal undergoes significant attenuation which considerably disrupts the operation of the assembly.

 The present invention thus relates to an optical quadrupole which can constitute an access coupler to a serial bus and which is such that it does not disturb the operation of the serial bus when a failure occurs.

 The optical quadrupole according to the invention thus comprises four branches each having means for receiving and / or for transmitting light rays and a deflection device having two operating states, a first state where it is reflective and is capable of returning light between a first and a second branch on the one hand, as well as between a third and a fourth branch on the other hand and a second state in which it lets light pass between the first and the fourth branches on the one hand, as well as 'between the second and third branches on the other hand.

 According to an advantageous embodiment, the four branches are coplanar and each branch forms an angle of 90 "with the adjacent branches.

 According to a first embodiment, the optical quadrupole constitutes an access coupler to a serial bus. For this purpose, the first branch is arranged to receive light signals carrying information from an upstream section of an optical data transmission line, the second branch is connected to a detector to detect said light signals, the third branch comprises an emitter of said light signals electrically connected to said detectors to produce light signals identical to the previous ones and send them in the third branch after amplification, the fourth branch comprises means for returning the amplified light signals to a downstream section of the transmission line of When the return device is in its first state, the optical quadrupole operates normally as a serial bus access coupler, and when the return device is switched to its second state, in particular when an abnormal operation of said detector and / or of said transmitter is detected by a control device, the detector and the transmitter are iso strips of the serial bus while allowing the transmission of information between said upstream section and said downstream section of the transmission line.

 According to a variant, the return device is switched to its second state to isolate the detector and the transmitter from the serial bus and make it possible to carry out tests on these.

 According to a second embodiment, the first and third branches respectively comprise a first and a second light signal transmitter and the second branch comprises means for transmitting said light signals. A control device is associated with each of the light signal emitters so as to control the switching of the return device between its first and its second state so that in the event of a fault, a light signal emitter in working condition can be substituted for a faulty transmitter.

 The means for receiving or for transmitting light rays comprise, according to a variant, a female connector for receiving a corresponding male plug of optical fiber connector so that the end of the optical fiber of the plug is in contact with a lens. and the lens is such that the light emerging from the optical fiber of the connector is transformed into a parallel beam thus defining an afocal operating zone for each branch and the deflection device is constituted by a mirror placed in a central part of the device and between the lenses, that is to say at the crossroads of the afocal operating zones of the different branches. Said plug advantageously includes a tip in which at least one optical fiber is precisely positioned at one of its ends as well as a plug body , and the end piece and the plug body comprise an elastic return element for pushing the end piece against a downstream end of the plug body. The tip is floating in the plug body. This floating tip is advantageously made thanks to a plurality of keying pins arranged at the downstream end of the plug body and to a corresponding number of grooves arranged on the tip, such so that it has a limited degree of freedom of rotation about its axis, and finally the plug body also includes at least a first keying element for angularly orienting the plug body in the connector and the plug body cooperates with a locking device intended to rigidly mount it on the fitting. The connector can then include an alignment device and at least one second keying element complementary to the first so as to provide the keying and the guiding of the plug in the connector.

 According to a preferred embodiment, the alignment device has two Vs and elastic return means for pressing the Vs of the end of the plug onto those of the alignment device so that the optical fiber of the endpiece is positioned on the optical axis of the lens.

 The alignment device is advantageously an alignment sleeve attached to the connector. The elastic return means may consist of an elastic tongue curved at one end and defining an elastic arm, the alignment sleeve being provided with an opening on the edge of which the end of the tongue is supported, a at least part of said arm opening out inside the alignment sleeve.

 According to a first variant, the deflection device is a removable mirror.

 It can be mounted in a support movable in translation between two positions, a first where the mirror is positioned on the passage of the light rays and a second where the passage of the light rays is provided by two openings in the support.

 The deflection device - is, according to a second variant, a fixed mirror having said two states under the action of a control device. The fixed mirror can be mounted in an angularly adjustable support, the position of which is fixed by a locking system after adjustment.

 According to a first embodiment, the fixed mirror is an optical switch comprising a transparent wall traversed by the incident light rays, and at least one drop of a light-reflecting liquid is placed on at least one zone of said transparent wall, this zone being wettable by the liquid and located in the vicinity and - outside the place where the light rays pass through the transparent wall, and it comprises a moving part with two positions, a so-called resting part for which said drop rests on said wall in outside the passage of light rays and a so-called work where it applies said drop against the wall so as to interpose it on the passage of light rays and to deflect them, so that the optical quadrupole is in its first state . The reflecting liquid is preferably mercury. The moving part can be a plate having a transparent region located in the extension of the incident light ray. The wettable zone can be bordered on at least one of its sides not facing the place where the light rays pass through the transparent wall, by a thicker zone so as to produce a channeling of the liquid as well as a stop for the moving part when it is in the working position. The moving part advantageously carries an element made of magnetic material where a magnet secured to it and associated with an electro-magnetic control means for moving the wafer between its rest position and its working position.

 According to a preferred embodiment, the transparent region of the movable part is a central region thereof and the movable part, in the rest position, rests on at least two drops located on either side of the transparent central zone. The wettable zone is advantageously bordered by a thicker zone surrounding it, with the exception of a channel region where the drops meet when the moving part is in the working position.

 According to a second embodiment, the fixed mirror is an electrolytic cell controlled by a generator producing electrical pulses of given polarity making the cell transparent or of opposite polarity making it reflective.

 The invention also relates to an optical multipole comprising at least two optical quadrupoles as defined above, arranged so as to be superposed. The operation of the optical multipole can be controlled by a plurality of mirrors mounted on a common support and separated from each other by a distance equal to the distance between the axes of the optical quadrupoles, and alternating with openings spaced apart from the mirrors d 'A given distance equal to the stroke of the common support when it is actuated to switch together the optical quadrupoles between said first and second states.

The invention will be better understood on reading the description which follows, with reference to the attached drawings or:
- Figure 1 shows a general diagram of a serial bus with its access couplers;
- Figures 2a and 2b respectively represent an access coupler of the prior art and its equivalent diagram in the form of an optical quadrupole;
- Figure 3a shows in top view and in section an optical quadrupole according to the invention;
- Figures 3b and 3c show an optical quadrupole according to the invention respectively arranged as an access coupler to a serial bus and as an information injector in an optical line;
- Figures 4a and 4b respectively show in longitudinal section and in section along AA a ring comprising a lens and an alignment sleeve for aligning a floating tip of a fiber optic plug;
- Figure 5 shows in longitudinal section a branch of a quadrupole equipped with a ring as shown in Figures 4a and 4b;
- Figures a and 6b show respectively in vertical section and in top view an alternative mounting of the alignment sleeve and the ring relative to Figures 4a and 4b, the branch shown on the right of Figure 6a being particularly suitable for receive a photo-emitter and / or receiver element directly mounted on the lens;
- Figures 7a to 7d show respectively in side view, in partial side section, in section BB and in section CC a support carrying a mirror according to an embodiment of the invention;
- Figures 8a and 8b show a grooved cylindrical piece capable of receiving a variant of a support shown in Figures 7a to 7d and Figure 9, a variant of the central piece of Figures 6a and 6b and receiving the cylindrical piece shown in Figures a and 8b;
- Figures 10a and 10b show respectively in exploded view and in the assembled state an embodiment of a floating tip plug capable of being mounted on the alignment devices shown in Figures 4a, 4b, 5 and 6a; ;
- Figures 11a and 1b show respectively in longitudinal section and in end view a plug body shown in Figures 10a and 10b;
- Figures 12a and 12b show respectively in side and end view an end piece as shown in Figures 10a and 10b;
- Figure 13 shows in side view a limiter as shown in Figures 1 Oa and 10b;
- Figures 14a and 14b show an embodiment of an optical switch according to an embodiment of the invention;
- Figures 15a, 15b and 16 show a top view of various variants of the channeling of the reflecting liquid of the optical switch shown in Figures 14a and 14b;
- Figure 17 shows an electrolytic cell that can be used as a mirror according to an embodiment of the invention;
- Figure 18 shows an optical multipole combining in superposition two optical quadrupoles according to the invention;
FIG. 19 represents a support common to a plurality of mirrors which can be used for controlling an optical multipole according to FIG. 18.

FIG. 1 represents a serial optical bus comprising a line L and a plurality of access couplers T1, T2, T3, tu, ..., Ti,
T. Each of these access couplers allows passage downstream to
n the information from line L, but also allows it to be transmitted to detectors Ri. On the other hand, information can be injected into the serial bus by a transmitter E.

associated with each access coupler.

According to FIG. 2a, in the prior art, this access coupler function is carried out using two 3-way Y couplers, referenced
Y1 and Y2 and each comprising a main branch ensuring the continuity of the line L and a branch branch intended to supply a detector R. as regards the branch Y1 and receiving the signals produced by a transmitter Ei as regards the coupler Y2. The coupler Y1 is connected upstream to the line L by a connector C1 and downstream to a portion of line Li by a connector
C2. The coupler Y2 is connected upstream to the line portion Li by a connector C3 and downstream to the line L by a connector C4. The information received by the detector R. is further transmitted by a line L'i to the transmitter Ei so as to reinject these into the
II line L downstream after amplification. Indeed, the insertion losses due to the couplers Y1 and Y2 as well as to the connectors C1 to C4 introduce a very significant attenuation in line and it is therefore necessary to reinject amplified signals at the level of each access coupler.

 This has two consequences. On the one hand, the signals reelected by the transmitter E. in the line L must arrive in phase with the signals transmitted directly through the optical line Li and the line Li must, for this purpose, include a line to delay so as to compensate for the phase shifts occurring between the detection by the detector R. and the retransmission of the signals by the transmitter E. On the other hand, a failure in the detection or the retransmission of the signals entails that the only signal transmitted through the coupler is that which passes through the main branch of the couplers Y1 and Y2, the connectors C1 to C4 and the line portion Li. The attenuation produced is then very important and is likely to disturb or prohibit the operation of all the access couplers located downstream. In addition, if the serial distribution is done by a closed loop to which N terminals have access thanks to the couplers T1 to Tn as shown in FIG. 1, the line becomes practically unusable. for 'all users given that during a conversation between two terminals, either the information sent or the information received is lost.

 FIG. 2b shows a diagram equivalent to the diagram of FIG. 2a in the form of an optical quadrupole receiving at its inputs on the one hand the signal E on line and the signal emitted by the transmitter E. and producing at its output a signal S retransmitted in the line and a signal received by the detector R .. This signal is fed back to the transmitter Ei by the line L'i.

 The present invention relates to a component called an optical quadrupole capable of fulfilling in particular such a function, but which does not have the operating faults of the system described in FIG. 2a.

 According to FIG. 3a, an optical quadrupole according to the invention, designated by the general reference 1, comprises four branches A, B, C and D arranged at 90 "relative to each other and in the same plane, each constituting an optical transmission or reception channel 10 '. At the crossover 11' of the branches, at the center of a central element 11 having four extensions 10 and where the optical channels 10 'are bored, a deflection mirror 3 is arranged intended, when it is in a first state constituting a working state, to return the light rays from branch A to branch B and from branch C to branch D. The mirror 3 is, for this purpose, inclined to 450 with respect to each of the axes of the optical channels 10. In a second state, the mirror 3 is erased and the propagation of the light rays takes place directly from branch A towards branch D and from branch B towards branch C. This switching can be done by mechanical means erasing the mirror or the mirror can be re fixed and change state under the action of a control device modifying the propagation conditions.

 The optical connections are made at each branch by means of a plug 19 comprising an end piece 20 on the front face of which is flush with an optical fiber. The plug is locked in position in a female connector 10 by a plug 5 so that the fiber which is flush with the front face of the end piece 1 is in contact with a lens 2, here a rod lens, whose function is to resume the light beam which emerges from the optical fiber at an angle of divergence as a function of the digital aperture of the fiber, and to transform it into a parallel beam so as to define downstream of each lens 2 a zone 2 'of afocal operation for each plugged.

 The plug is designed so that the fiber flush with the front face of the end piece 20 is centered on the optical axis of the lens 2. The deflection device 3 depending on whether it is in one or the other of its states then puts in two-by-two optical communication the afocal zones 2 'of the various branches A, B, C, D. As the branches A and D are in the extension of one another, the optical axes of the lenses 2 of each of these branches are aligned on an axis XX '. Likewise, the optical axes of the lenses 2 of the branches B and C are aligned on an axis YY ′, and the lenses 2 are centered, for this purpose, in a ring 39.

 It will also be noted that the branches A, B, C and D of the optical quadrupole do not necessarily need to form an angle of 90 between them. Indeed, the angle between the axes XX 'and YY' can be arbitrary insofar as the return device is inclined in an appropriate manner, that is to say is located on one of the bisectors of the axes XX 'and YY '.

 According to FIG. 3b, the branch A of the optical quadrupole receives a signal from a line L of optical transmission. The deflection device is arranged so as to return the light coming from the line L in one of the branches adjacent to the branch A, here the branch B, to which the light is transmitted by rotation of 900 to the right in the direction of the propagation. The plug 19 of branch B comprises an optical fiber connected to a terminal optical receiver R. which on the one hand receives the signals of the line and retransmits them by an auxiliary line L '. to a terminal optical transmitter E. and on the other hand decodes the information with a view to its use. The optical transmitter E. is connected to branch C situated in the extension of branch B and the return device 3 returns the light towards branch D located in the extension of branch A, here by rotation of 90 "to the left in the direction of the propagation of light. The terminal optical transmitter Ei is also associated with a detection device intended to check the operation of the transmission of information by carrying out various tests known per se on the emission signals of the transmitter E..This detection makes it possible to know if there has been a failure at the level of the transmitter or the receiver, and in this case, to activate a control device to switch the return device 3 to its second state where it will let the light pass directly from line L of branch A to branch D.

In the event of a fault, the access coupler is put out of service by isolating its detector and its transmitter and the transmission of the light carrying the information is done directly from branch A to branch D with relatively low losses (which can be around 2 decibels or less) provided by the connector + lens system. In the absence of a fault, one can also take advantage of this possibility of isolating the detector and the transmitter from an access coupler to carry out more in-depth tests of these and / or maintenance operations.

According to FIG. 3c, two adjacent branches A and C are each connected to a laser 1 and 2 respectively capable of sending an information-carrying light in a line
L connected to the output of branch B located in the extension of branch C. In this case, the switching of the deflection device 3 between these two states makes it possible to activate the laser I or the laser 2. A control device is associated with - each of the two lasers and a control device makes it possible to switch the return device 3 according to one or the other of these states in the event of a failure of one of the two lasers. This switching could also be performed by an information receiver located in line L.

Note, moreover, that the fourth branch of the quadrupole D remains at any time usable for checking the operation of that of the two lasers which is not in service in the branch B, which makes it possible to carry out its development. without disturbing the operation of the L line.

 According to FIGS. 4a, 4b and 5, a centering ring 39, in the front part 37 of which a lens 2 is centered thanks to a crimping 44, is mounted in the bore 10 'of a cylindrical part 10, the end constitutes a threaded connection at 34 intended to receive a plug with floating tip. The ring 39 abuts on a cylindrical part 10 "of smaller diameter and is fixed in position by means not shown. It can carry on its outer surface ribs 29 'forming keying keys which correspond to keying grooves 29 provided in the bore 10 '. The polarization is assured, it will be recalled, conventionally by the fact that all the ribs do not have the same width.

 In FIG. 4a, more particularly, the position of the elastic tongue 35 will be noted. This tongue is held by the lateral edges of a groove 13 formed in a bore 20 of the ring 39. An alignment sleeve 41 is made integral of the ring 39 by a fixing screw 28. The tongue 35 is held longitudinally in the groove .13 by a flange 46 of the alignment sleeve 41 with a certain play facilitating assembly. The elastic tongue comprises an arm 38 resting on an inclined edge 48 of the alignment sleeve 41 and ends in a boss 40 which, after assembly, opens into the inner channel 20 of the alignment sleeve 41. It will also be noted (see figure 4b) the clearance h between the flat part 35 ′ of the elastic tongue 35 and the bottom of the groove 13 in the absence of the connection end piece. During the introduction thereof, the arm 35 ′ forming the flat part of the tongue 35 is pressed outwards, the shape of the bosses and of inclination of the arm 38 relative to the flat part 35 ′ having to be sufficient to allow the tongue 35 to perform its function of pressing a corresponding V-shaped tip at the bottom of a V-shaped groove delimited by planes 16 and 17 connected by a rounded 18.

 The V-shaped groove is precisely made to serve as a reference. The cylindrical end-piece or itself provided with a corresponding V-shaped profile has an optical fiber positioned with precision, so that the plating of the end-piece ensures the positioning of the fiber on the optical axis of the lens 2.

 According to the variants of variants 6a and 6b, at least one of the branches A, B, C and D is attached by screwing on a central support 11 "carrying the mirror 3 and on which the lenses 2 'are crimped at 44' in 4 bores each corresponding to one of the branches. The mirror 3 is carried by a support 58. Each of the sleeves 47 is fixed by a flange 49 ensuring precise centering with respect to the lens 2 '. Each of the sleeves 47 carries an alignment sleeve 41 "attached, similarly fixed to the sleeve 4i by a screw not shown. The sleeve 41 'is, moreover, identical to the sleeve 41 with regard to its V-shaped profile and the fixing of a spring 35 having a branch 38. According to a variant concerning the optical emission or detection devices and represented on the right-hand branch of FIG. 6a, a photo-emissive element or photo detector 140 is precisely centered in a sleeve 47 'centered itself even with precision on the support central 11 'by fixing to a flange 49'.

As in the previous case, the central support 11 ′ comprises in the corresponding bore a lens 2 ′ set at 44 ′.

 According to Figures 7a to 7d, the support, which is suitable in the case where the switching of the deflection device is effected by change of state thereof without it moving, is of generally cylindrical shape and has a longitudinal slot 59 extending from its upper face 99 and which is intended to receive the mirror 3 which will be pressed against a face 59 ′ of the slot 59 by screws 62. The face S9 ′ is machined with precision so as to be strictly parallel to the longitudinal axis of the support 58 which ensures the vertical positioning of the mirror 3. The angular position of the support 58 around its axis will precisely determine the angle of deflection of the light rays. This positioning can be carried out with precision in situ. To this end, the lower face 99 ′ of the support 58 which forms a collar with a diameter slightly larger than that of the cylinder forming the support 58 so as to constitute a stop, is provided with a groove 74 with a U-shaped profile capable of being brought into contact with a corresponding male part of a micro-manipulator. The adjustment is then made as follows. The optical quadrupole is placed on the micro manipulator so that its head is able to rotate the support 58 through the groove 74. A light signal is sent to one of the branches of the quadrupole and the micro-manipulator is activated. so as to rotate the support 58 until a signal of maximum amplitude is obtained in the corresponding adjacent branch after deflection by the mirror 3. The support 58 is then fixed in position by a screw 95 (see FIG. 6b ). The passage of the light rays to and from the mirror 3 is ensured by a pair of orthogonal bores 60 arranged in a plane perpendicular to the axis of the support 58 and which open into the groove 59.

 Figures Sa, 8b and 9, there is shown an assembly allowing the translation of the support carrying a deflection device, here the mirror 3 to put the latter according to its first or its second state thanks to a displacement by translation and nevertheless allowing to maintain angular positioning accuracy. To do this, the support 58 is angularly positioned in a cylindrical sleeve 84 after adjustment on a standard device and locked in position by a screw inserted in a tapping 85. The cylindrical sleeve 84 is provided with two pairs of bores 94 substantially aligned with the axis of the bores 60. On the other hand, the cylindrical sleeve 84 carries on its outer part longitudinal grooves 80 machined with precision cooperating with corresponding ribs 79, also machined with precision, of the bore 78 of the central part 11 "of the optical quadrupole (see FIG. 9). When the mirror 3 is in its first state, the optical axis of the quadrupole passes through the bores 60. By translation, the cylindrical sleeve is brought into a second position where two pairs of bores 98 formed therein and aligned with two pairs of bores 97 formed for this purpose in the support 58 (see FIG. 7a) allow free passage of light along the axes XX 'and YY' of the quadri pole. The bores 97 are formed between the bottom of the groove 59 on which the mirror 3 rests and the lower part 99 'of the support 58.

 The plug shown in Figures 10a and 10b includes a plug body 52 having at its front part 51 keying keys 22 and 23 as well as ribs 24 and 25 intended to orient the plug body 52 in the extension 10 forming a connector and a flange 30. This sheet has the advantage of having a floating tip and of allowing a pre-orientation of the latter relative to the alignment sleeve 41. The pre-orientation (or polarization) function is achieved by cooperation of the ribs 24- and 24 of the front part 51, of the groove 13 of the ring 39 and of keying grooves 29 formed for this purpose in the ring 39.

 A nozzle 20 comprising a front part 61 provided with a V 62 comprises at its downstream end 68 an optical fiber precisely positioned and fixed in position by glue introduced by a hole 69. The plug body 20 has at its rear part tri-flange 63 in which grooves 64 are provided intended to cooperate with the polarizing keys 22 and 23. The sheath of the optical fiber cable of the connection L is held by crimping thanks to a ferrule 6, a cannula 9 and a washer 7 The ferrule 6 has at its front part a six-sided collar 56. A limiter 4 (see also FIG. 13) through which the optical fiber passes has at its front part a housing 71 for a spring -21 and at its rear part a flange 73 with a hexagon. A locking ring 5 provided with a inner flange intended to come into abutment on the flange 30 of the plug body is intended to be screwed onto the thread 34 of the extension 10 forming a connector by its corresponding thread 32 so that the plug body is rigidly locked on the connector. The mounting of the plug is carried out by means of a rear nut 8 having a thread 43 coming to be screwed into a thread 53 corresponding to the rear part of the plug body. This rear nut 8, associated with a washer 7 providing it with better range, keeps the limiter 4 and the ferrule 6 in position in a hexagon housing 75 disposed at the rear of the plug body 52 (see FIGS. 1a and 11b). ), The end piece 20 being held in position in a floating manner by the spring 21. The locking ring is capable, before screwing, of a longitudinal movement between the flange 30 and the front part of the rear nut 8.

 According to FIGS. 12a and 12b, the floating end piece 20 comprises a front cylindrical part 61 along which two orthogonal cut sides 62 are formed forming a V. The cylindrical part 61 ends at the front by a rounded 69 'in the center from which an optical fiber is precisely positioned at 68. The rear end of the cylindrical part 61 is extended by a flange 63 in which grooves 64 are formed. These grooves are angularly spaced in the same way as the locking keys 22 and 23. The bottom 65 of the grooves serves as a stop for the end piece 20 in the keys 22 and 23 of the plug body 52. The grooves 64 are slightly wider than the corresponding keys 22 and 23, which gives the end piece a degree of freedom of rotation along its axis, but limited in amplitude. The collar 63 is extended towards the rear by a cylindrical part 66 intended to receive around it the spring 3.

 The assembled plug therefore comprises a plug body 52 and a floating end piece 20 having a degree of longitudinal freedom thanks to the return of the spring 21, a degree of freedom in rotation about its axis thanks to the fact that the grooves 63 are wider than the corresponding keying keys 22 and 23. The endpiece also has a degree of freedom by translation perpendicular to its axis and a freedom of rotation substantially around its rear end thanks to the mechanical play existing on the one hand between the outside diameter of the flange 63 and the inside diameter 77 of the front cylindrical part of the plug body 52, and on the other hand between the diameter delimiting the bottom of the grooves 63 of the end piece 20 and the inside diameter in which the locking keys 22 are inscribed and 23. In practice, the clearances chosen will be related to the manufacturing tolerances of the parts forming the connector. In the figures, the bottom diameter of the grooves 63 is equal to that of the front cylindrical part 61 of the end piece.

 For example, for an internal diameter of the internal cylindrical part 77 of the plug body equal to 5.6 mm and a keying key height equal to 0.6 mm, an axial clearance of 1.5 tenths is chosen. of a millimeter, and on the end piece 20 the grooves 64 have a width of 2 mm for a width of the keys 22 and 23 equal to 1.6 mm so as to allow the end piece to rotate on itself.

The recoil distance of the nozzle will be chosen in the order of 0.6 mm.

 As a variant, the floating tip 20 comprises a photo-emitter and / or-receiver element precisely positioned at its end, allowing direct coupling of the latter without intermediate optical fiber.

 The optical switch represented in FIGS. 14a and 14b and designated by the general reference 3 ′ comprises a transparent plate 81 forming part of a housing comprising a second transparent plate 83 disposed above the plate 81 and spaced from the latter by a wall side 82 forming a spacer. The transparent plate 81 has on its inside face of the housing two surfaces wettable by a light-reflecting liquid, for example mercury. On each of these two surfaces, a drop of mercury, respectively 87 and 88, is arranged. For mercury, a known treatment consists in depositing, for example, copper by the usual metallization processes and in following the deposit by a treatment. thermal around 3000C in the presence of mercury when the housing is sealed. The wettable surfaces are chosen not to be located on the passage of a light ray 86, but on both sides of it. The material of the plate 81 is chosen in such a way (for example glass) that it is not wettable by the chosen liquid. The wettable surfaces are partially surrounded by regions 89 and 90 preferably non-wettable by the liquid and of thickness greater than that of the wettable surfaces. For example, chromium is not wettable by mercury. Their function is to channel the drops 87 and 88 during the operation of the switch and to serve as a stop ensuring the precise positioning of a plate 91 of optically transparent material which is free to move and which is disposed above the drops 87 and 88 resting on them. The lower surface of the wafer 91 in contact with the drops is preferably not wettable by the liquid. The plate 91 carries at least one element 92 of magnetic material or a magnet which is joined thereto integrally, and placed in such a way that it does not interrupt the light beam 86. Under the transparent plate 81, a magnetic winding 93 is arranged. The application of a current in the coil 93 creates a magnetic field attracting the whole of the plate 91 and the element 92 towards the coil 93. This situation is represented in FIG. 14b where the plate 91 crushes the drops 87 and 88 so as to form a single drop 17 resulting from the deformation and the joining of the drops 87 and 88. The resulting drop 17 is then applied by the plate 91 against the internal face of the transparent plate 81. device then works like a mirror. The light rays 90 and 96 which have an angle of incidence of 45 "with the lower plate 81 and the plate 91 respectively are deflected at right angles, according to rays respectively 86" and 96 ', the positioning of the assembly being chosen so that 96 'is an extension of 86.

 The positioning of the optical switch can be achieved by placing it in a support 58 as shown in Figures 7a to 7d.

 It will be noted that the optical switch described above is particularly advantageous because it can operate in practically all positions since its operation essentially uses capillary forces.

 In FIG. 15a, the wettable zones 104 and 105 are shown surrounded by zones 109 and 100 forming a U 111, 113, 114, 120 which surrounds on three sides the wettable zones 104 and 105. The zones 109 and 110 extend also at 114 to partially close the fourth side of wettable areas 104 and 105.

This defines a channel 127 between the drops as well as two channels 118 forming a buffer volume. The fact that the channel 127 has a significantly smaller section than that of the zones 104 and 105 promotes the separation of the drop 17 into two separate drops when the wafer 91 is no longer attracted by the action of the electromagnet 93 .

According to the variant of FIG. 15b, the branches 113 and 114 have profiled zones respectively 115 and 116 so that a converging channel 128 in the form of a diabolo is produced.

This shape gives a great possibility of expansion at the surface of the liquid while ensuring a minimal contact surface between the two drops of liquid, favorable for the production of a monostable.

FIG. 16 represents, on the other hand, an embodiment of the invention favorable to operation in bistable mode. To do this, the branches 111 and 112 are extended by arms 108 and 117 respectively delimiting a channel 129 wider than the wettable surfaces 104 and 105. In this configuration, the contact surface between the drops is increased. To provide the energy corresponding to the increase in external surface which occurs during the separation of the drops, it is necessary to provide an external work
This work is provided by the energy provided to move the wafer from its working position to its rest position.

 It will be noted that the width of the space between the wettable zones also plays a role since there occurs, in the non-wettable zone which separates them, a necking of the drop, the greater the greater this width.

 According to FIG. 17, an optical switch is constituted by an electrolytic cell 3 ". An organic electrolyte 106 is enclosed in a housing constituted by a thin glass blade 111, a cylindrical piece 107 and a second thin glass blade 111 '.

A silver electrode el in the form of a ring is fixed on the inner wall of the blade 111. A transparent electrode e2 is deposited on the underside of the blade 1111 and projects beyond the cylindrical face of the latter. A voltage V can be applied between the electrodes el and e2 by means of an electric control generator 101.

If the potential of the e2 electrode is negative, the silver of the electrolyte is deposited there making the surface of the e2 electrode reflective. On the other hand, if the potential of the electrode is positive,
The silver dissolves, is deposited on the el electrode and the cell becomes transparent. Such a cell therefore constitutes a mirror with two operating states which can be mounted in a barrel such as 58.

FIG. 17 also shows the path of the incident light rays 86 and 96 as in the case of FIG. 14b.

 In FIG. 18, two superimposed optical quadrupoles 120 and 121 are shown, the central openings 122 and 123 of which are positioned along the same vertical axis.

 In FIG. 19, two mirrors 124 and 126 have been shown set in the same support 130 and separated by a distance d equal to the center distance between the two superimposed quadrupoles 120 and 121. Openings 125 and 127 are spaced apart from the mirrors 124 and .126 with a distance h 'equal to the stroke of the support 130 allowing the two optical quadrupoles to be switched together from the first to the second state by translation of the support 130. In the first state, the mirrors 124 and 126 are interposed on the path of the light rays so as to produce a deflection of these and in the second state the openings 125 and 127 allow free passage to the light rays.

 The invention is not limited to the embodiments described and shown. Thus, rod lenses can be replaced by gradient index lenses fulfilling the same function. Likewise, the mechanical movement of the deflection device can be carried out differently than by translation, in particular by rotation about an axis, the position of the mirror in the active position being defined by a precision stop. On the other hand, in the event that the mirror undergoes a translational movement, the latter may carry means cooperating with a precision slide as well as a magnet, and its movement is then controlled by a coil disposed in an appropriate manner with respect to to the magnet.

Claims (25)

 1. Optical quadrupole characterized in that it comprises four branches (A, B, C, D) each having means (2, 19, 20) for receiving and / or for transmitting light rays and a deflection device (3 ) having two operating states, a first state where it is reflective and is capable of returning light between a first (A) and a second (B) branch on the one hand, as well as between a third (C) and a fourth (D) branch on the other hand and a second state where it lets light pass between the first (A) and the fourth (D) branch on the one hand, as well as between the second (B) and the third ( C) on the other hand.  2. Optical quadrupole according to claim I, characterized in that the four branches (A, B,, D) are coplanar and in that each branch forms with the adjacent branches an angle of 900.  3. Optical quadrupole according to one of claims 1 or 2, characterized in that the first branch (A) is arranged to receive light signals carrying information from an upstream section of an optical line (L) for data transmission , in that the second branch (B) is connected to a detector (Ri) for detecting said light signals, in that the third branch (C) comprises an emitter (Ei) of said light signals electrically connected (2) to said detector ( Ri) to produce light signals identical to the previous ones and send them to the third branch (C) after amplification, in that the fourth branch (D) includes means for returning the amplified light signals to a downstream section of the transmission line data so as to operate as an access coupler to a serial bus when the return device (3) is in its first state, and in that it comprises means for passing the return device (3) into its second state of so as to isolate the detector and the transmitter forming an access coupler from the serial bus while allowing the transmission of the information between said arnont section and said downstream section of the transmission line.  4. Optical quadrupole according to one of claims 1 or 2, characterized in that the first branch (A) comprises a first transmitter (I) of light signals, in that the second branch (B) comprises means for transmitting said light signals , in that the third branch (C) comprises a second emitter of light signals, in that it comprises a control device associated with each of said emitters of light signals so as to control the switching of the return device ( 3) between its first and its second state so that in the event of a fault, a light signal transmitter in operating condition can be substituted for the faulty transmitter.  5. Optical quadrupole according to one of the preceding claims, characterized in that said means for receiving or for transmitting light rays comprise a female connector (10) for receiving a corresponding male plug of fiber optic connector so that the end ( 68) of the optical fiber of the plug (69) is in contact with a lens (2) -and in that the lens (2) is such that the light emerging from the optical fiber of the connector is transformed into a parallel beam thus defining an afocal operating zone (2 ′) for each branch, and in that the deflection device is constituted by a mirror (3) disposed in a central part of the device (11) and between the lenses (2), this is ie at the crossroads (11 ') of the afocal operating zones of the different branches.  6. Optical quadrupole according to claim 5, characterized in that said plug (19) has a tip (6 ') in which at least one optical fiber (6') is precisely positioned at one of its ends as well as a body plug (52), in that the end piece (61) and the plug body (52) comprise an elastic return element (21) for pushing the end piece against a downstream end of the plug body (52) and in that the end piece (61) is floating in the plug body (52).  7. Optical quadrupole according to claim 6, characterized in that the end piece (61) is made floating in the plug body (52) by means of a plurality of polarization keys (22, 23) arranged at the downstream end of the plug body and a corresponding number of grooves (63, 64) arranged on the end piece (61), so that it has a limited degree of freedom of rotation about its axis, in that the plug body ( 52) also comprises at least a first keying element (24, 25) for angularly orienting the plug body in the connector (10), and in that the plug body (52) cooperates with a locking device (5) intended to rigidly mount it on the fitting (10).  8. Optical quadrupole according to claim 7, characterized in that said connector (10) comprises an alignment device (37) and at least one second polarizing element (29) complementary to the first (24, 25) so as to produce the keying and guiding of the plug (19) in the fitting (10).  9. Optical quadrupole according to claim 8, characterized in that the alignment device (37) has two Vs (16, 17) and means (35) for elastic return to press the Vs of the end piece (61) of the plug (19) on those (16, 17) of the alignment device so that the optical fiber of the tip (61) is positioned on the optical axis (XX ') of the lens (2).  10. Optical quadrupole according to one of claims 9, characterized in that the alignment device is a sleeve (37, 50) attached in the connector (10).  11. Optical quadrupole according to claim 10, characterized in that the elastic return means consist of an elastic tongue (35) curved at one end and defining an elastic arm (38, 40), the alignment sleeve (41) being provided with an opening (20) on the rim (48) from which the end (40) of the tongue bears, at least part of said arm (38) opening out inside the sleeve alignment (41).  12. Optical quadrupole according to one of the preceding claims, characterized in that the deflection device is a removable mirror (3).  13. Optical quadrupole according to claim 12, characterized in that the mirror (3) is mounted in a support (58) movable in translation between two positions, a first where the mirror (3) is positioned on the passage of light rays and a second where the passage of light rays is provided by two openings (97) formed in the barrel (58).  14. Optical quadrupole according to one of claims 1 to 11, characterized in that the return device is a fixed mirror (3 ', 3 ") having said two states under the action of a control device.  15. Optical quadrupole according to claim 14, characterized in that the fixed mirror is mounted in a support (58) angularly adjustable and whose position is fixed by a locking system (95) after adjustment.  16. Optical quadrupole according to one of claims 14 or 15, characterized in that the fixed mirror is an optical switch comprising a transparent wall (81) traversed by the incident light rays (86), at least one drop (87, 88) d 'a light reflecting liquid being arranged on at least one area (104, 105) of said transparent wall, this area being wettable by the liquid and located in the vicinity and outside of the place where the light rays (86) pass through the transparent wall (81) and in that it comprises a movable part (91, 92) with two positions, a so-called rest for which said drop (87, 88) rests on said wall (81) outside the passage of light rays ( 86) and a so-called work where it applies said drop (87, 88) against the wall (81) so as to interpose it on the passage of the light rays (86) and to deflect them so that the quadrupole optics is in its first state.  17. Optical quadrupole according to claim 16, characterized in that said light-reflecting liquid is mercury.  18. Optical quadrupole according to one of claims 16 or 17, characterized in that the moving part is a plate (91) having a transparent region located in the extension of the incident light ray.  19. Optical quadrupole according to one of claims 16 to 18, characterized in that the wettable zone (104, 105) is bordered on at least one of its sides not opposite the place where the light rays pass through the transparent wall, by a thicker zone (him, 112, 120, 114) so as to produce a channeling of the liquid as well as a stop for the moving part (91, 92) when it is in the working position.  20. Optical quadrupole according to claim 19, characterized in that the moving part (91) carries an element (92) of magnetic material or a magnet, integral with the latter associated with an electro-magnetic control means (93) for move the insert between its rest position and its working position.  21..An optical quadrupole according to one of claims 16 to 20, characterized in that said transparent region of the moving part (91, 92) is a central region thereof and in that the moving part (91, 92) in rest position, rests on at least two drops (87, 88) located on either side of the transparent central zone.  22. Optical quadrupole according to claim 21, characterized in that the wettable zone (104, 105) is bordered by a thicker zone (111, 113, 114, 115, 116, 120) surrounding it except for a channel region (127, 128, 129) where the drops (87, 88) meet when the moving part (91, 92) is in the working position.  23. Optical quadrupole according to claim 14, characterized in that the fixed mirror is a common electrolytic cell (3 ") supplied by a generator (101) producing electrical pulses of given polarity making the cell transparent or of opposite polarity making it this reflective.  24. Optical multipole characterized in that it comprises at least two optical quadrupoles (122, 123) according to one of the preceding claims, arranged so as to be superposed.  25. Optical multipole according to claim 24, characterized in that it comprises a plurality of mirrors (124, 126) mounted on a common support (130) and separated from each other by a distance (d) equal to the distance between the axes of the optical quadrupoles (122, 123) alternating with openings (125, 127) spaced from the mirrors by a given distance (h ') equal to the stroke of the common support (130) when the latter is actuated to make switching the optical quadrupoles (122, 123) together between said first and second states.