SE438918B - CONTROL OF CONNECTION BETWEEN OPTICAL FIBERS AND SETS FOR ITS MANUFACTURING - Google Patents

Description

7800208 ~ 6 the ends of the single optical fibers and their interface or connection port.

For example, misalignment transversely or laterally of the ends of the fibers relative to each other causes considerable signal loss across the boundary surface, which increases with increasing lateral displacement, for example up to about 4 db at a lateral displacement equal to half the fiber diameter. Separation in the longitudinal separation of the fiber ends or end displacement also entails considerable signal loss, which increases with increasing end separation, for example up to about 1.5 db with an end separation of half the fiber diameter. Axial or angular error adjustment also contributes to the coupling inefficiency, the loss increasing with the angle between the end faces of the optical fibers, for example a loss of approximately 1 db is obtained for an angle of 5 °. The signal losses that result from transverse displacement, end separation, axial misalignment as well as losses due to Fresnel reflections are cumulative.

It is thus essential to provide a coupling, the ends being in line with each other transversely and axially and intimately abutting each other. Prior art coupling and splicing techniques have not been able to provide such a shaft closure edge via a simple element which is inexpensive to manufacture, nor have such connectors been easily reused. According to a previously known coupling technique for splicing, for example, a square glass tube is used, which is pre-filled with an epoxy plastic of suitable refractive index. The fiber ends to be joined are inserted into the tube and bent so as to cause the tube to rotate, after which the fibers are forced into a corner and adjusted axially.

The fibers were then lined against each other end to end. When the epoxy plastic solidifies, a permanent joint or splice is obtained. According to another coupling technique, a stainless steel pipe with a central bore is used, into which a fluid of suitable index is inserted. The ends of the optical fibers are inserted into the bore from rooted ends, after which the tube is deformed, so that a permanent joint is obtained. Although the above-mentioned types of connectors relatively effectively reduce transmission losses across the interface, the tubular connectors are difficult to use and expensive to manufacture. Furthermore, the connection obtained is permanent, ie. a splice, and can not be separated without 78002Û8-6 that the coupling member is destroyed.

Various releasable and lockable connectors have been described in patents and in the technical literature. For example, an optical connector assembly using different types of fiber placement and setting devices is described in an article entitled "Demountable Connectors For Optical Fiber Systems", by M A Bedgood, J Leach and M Matthews in Electrical Communication, Volume 51, no. 2, 1976. Among the various end adjusting devices described therein are 1) a precision shoe made of stainless steel, in one end of which a bell ruby hole is arranged for adjusting the ends of the optical fibers attached to the shoe, 2) a double shoe connector, in which an inner shoe, in which an optical fiber is arranged and locked by means of epoxy plastic, and an outer shoe, which houses the inner shoe, and 3) X-stone connection judgment in which a shoe is used, at one end of which an X-stone is locked for adjusting an optical fiber locked therein by gluing, and a fitting shoe with a silicone rubber icon at its tip - and through which the optical fiber extends, the cone fitting into the X-stone when the shoes are brought together.

It has been found that one of the best ways to set up a round optical fiber is to provide contact with the fiber at equally spaced points around its periphery. An article entitled "Optical Wave Guide Cable Connection" by E 'L Thele and RM Havvk in Applied Optics, November 1976, shows a connector with a fiber setting and retention control for touching the fiber at equally spaced locations around its periphery. for this purpose the conductor comprises a set of three rods of plastic or plastic-coated and of equal diameter.The diameter of the rods is predetermined so that the optical fiber to be adjusted and retained fits snugly in the set, and the rods are slightly deformed by their contact with the fiber, so that it is held in place.

The rod set guide adjusts and holds the fibers efficiently, but the frictional contact due to the tight contact between the plastic rods and the fiber makes it difficult to place the fiber in the longitudinal direction. Furthermore, the soft material of the rod can lead to damage to the “7800208-6” surfaces during the locking operation, so that an unnecessary light leakage or light loss source is obtained.

The use of a three rods including a wire mechanism or conductor together with a tubular connector is also shown in an article entitled 'Connecting The Thread Of Light' by Kenne J Fenton and Ronald L. McCartney, published at the Ninth-Arlnual Connectors Symposium, 20 and 21. October 1976, Cherry Hill Hyatt House, Cherry Hill, New Jersey, USA The publication describes three rods comprising plastic or deformable conductor, which are used for adjusting and holding one fiber end in a fiber optic end or connector part. The other fiber end to be spliced, The connection parts are fitted together and locked using a tube of elastomeric material with an hourglass-shaped central channel, into which the mutually insertable parts are inserted. effectively the ends of the optical fibers together in a small light beam desire to have a joint, but the construction is relatively complicated and should require considerable manipulation to achieve the correct connection.

Various other types of optical fiber connectors have been described in the patent literature, for example, U.S. Patent Nos. 3944327, 3944328, 3947182, 3948582, 3950075, 3947088, 3951514- and 3951515.

All of the prior art devices mentioned above have one or more disadvantages, and there is a need for a good assembly of conductors and connectors.

The present invention aims to provide a guide used in connection between optical fibers which is not encumbered with the disadvantages of prior art devices. The control must be simple in construction and must be able to be used together with a single-fiber conductor to achieve a low-loss joint between a pair of fiber ends.

The guide should be reusable and should facilitate the precise placement and adjustment of a pair of optical fibers. 7800208-6 The invention further provides a method of connecting optical fibers.

The guide of the invention is used to provide an optical signal transmitting connection between a pair of optical fiber ends. The guide is characterized by an integrated unit of at least three side-by-side, parallel glass elements of predetermined length and with cylindrical surface parts and co-ordinating with each other along longitudinal peripheral parts, in which unit the glass element elongates a longitudinal, open-ended channel. whose cross-section has a shape which has tips and which has smooth surfaces for guiding the ends of a pair of optical fibers, which are inserted into the channel until they come in close proximity to each other, so that they form a good, optical signal transmitting joint. .

The ends of the glass elements have a smaller diameter than the glass elements in general, so that the opening at each end of the channel has a larger cross-sectional area than the middle part of the channel. The conductor is arranged in a connecting element which is formed by a pair of mating connecting elements. Each coupling element comprises a passage which extends through the element in its longitudinal direction for receiving the respective fibers.

Each coupling element is terminated with a hollow part next to one end.

The elements are connected to each other at this end so that the hollow areas form a cavity for the conductor element. The passages comprise enlarged openings at their other or outer ends, which taper in the cross-sectional area towards the entrance to the cavity. The cross-sectional area of the passage at the entrance to the cavity is only slightly larger than the cross-sectional area of the optical fiber extending therethrough and into the conductor element. Adjusting means are provided to ensure that each fiber extends a predetermined distance into the cavity so that when the coupling elements are connected the fiber ends of the conductor abut each other in a joint of good optical signal transmission capability.

The invention is explained in more detail below with reference to the accompanying drawings. Fig. 1 is a perspective view of the assembly of conductors and connectors according to the invention, shown connecting the ends of a pair of simple optical fiber cables, Fig. 2 is a strand perspective view of the assembly of Fig. 1, Fig. 3 shows a section in larger scale in the plane 3-3 in Fig. 1, Fig. 4 shows a section on a larger scale in the plane 4-4 in Fig. 3, Fig. 5 is a partial view on a larger scale of a part of the one in Figs. Fig. 6 is a perspective view on a larger scale of one end of the conductor element according to Fig. 2, Fig. 7 is a sectional view similar to Fig. 4 but showing an alternative embodiment of the invention, Fig. B is a sectional view , which on a larger scale shows an alternative embodiment of the conductor element according to the invention, and Fig. 9 is a sectional view, which on a larger scale shows an alternative embodiment of the conductor element according to the invention.

In Fig. 1, one assembly of conductors and connectors for use in fiber optic devices is shown for providing telpore or permanent connection between a pair of optical signal carrying fibers. as will be apparent from the following: the following zo, also called aggregates, can be assembled quickly and easily and are particularly suitable for joining end to end of simple optical fibers in sheathed cables while maintaining low loss and low crosstalk for Furthermore, the guide or assembly 20 enables the fibers to be permanently connected to form a splice or to be easily and repeatedly connected and disconnected.B 7800208-6 Basically, the assembly comprises a conductor element 22, which is arranged to be held in an inner cavity (described). in more detail below) in a lockable housing or connector 24. The conductor element is arranged to facilitate the precise axial adjustment and joining of the ends 26 (Fig. 2) of a pair of simple optical fibers 28 in a conventional, sheathed cable 27, so that a joint light transmission capacity (low loss) is obtained.

The conductor element comprises at least three identical, elongate, rod-shaped glass elements 30. The elements 30 are arranged side by side in a parallel arrangement with the longitudinal parts abutting each other and interconnected. The set of rod-shaped elements forms a central inner space or channel 34 (Figs. 5 and 6) between the rods, which extend along the entire length of the conductor.

The inner space 34 is in the form of a central channel with a plurality (namely three) of pointed spaces 36, which emanate from the channel and which extend along the entire length thereof, each space lying between a pair of abutting, rod-shaped elements. The channel 34 is arranged to receive the ends of the optical fibers to be joined together so that they are adjusted coaxially. The diameter of the rod-shaped elements is chosen so that the diameter of the central channel part between the rods is slightly and evenly slightly larger than the diameter of the fibers to be joined together. It should be noted that the conductor 22 can, if desired, be formed by more than three rod-shaped elements 30. In such a construction, the central channel comprises the same number of pointed spaces as the number of rod-shaped elements in the set.

Preferably, the conductor member 22 is formed of glass by drawing glass rods of larger diameter to the required size, the rods being brought into contact with each other while hot, so that the longitudinal portions of their peripheral edges come into contact with each other and coalesce. 7800208-6 The user age of glass for Irraterial for the conductor is essential from a manufacturing point of view (glass can be easily drawn) and from a functional point of view.

From the semare point of view, glass is less likely to shrink, so that dimensional stability is added to the conductor. Furthermore, glass offers a hard but even gap surface, which is resistant to wear and corrosion. These features ensure that the optical fibers 26 are not scratched, scratched or otherwise damaged when inserted into the conductor as described below, nor is the conductor damaged. Damage to both conductors and fibers causes unnecessary light loss through the damaged surfaces. Furthermore, the transparency of the glass guide element allows consideration of the placement of the fiber end regions, which facilitates the connection of the fibers.

The pointed shape of the central channel 34 is significant in that when an optical fiber is inserted into the channel, the only parts thereof which come into contact with the three parts 38 formed by the inner rod surface portions of the rod-zilmaride elements 30 are. The tangential three-point contact acting with the conductor element 22 allows a fiber to be inserted with very little friction between it and the conductor element; furthermore, since the parts ae which come into contact with the fibers, at equally distributed places around the periphery, fiber end anches are in place in the conductor in a carefully axially set ooh "centered manner. diameter of the channels 34 in the conductor element 22, each open end 40 has a larger cross-sectional area than the remaining part of the channel (see Fig. 6) .The enlargement of the openings 38 in the conductor element 22 is conveniently achieved by dipping the ends of the conductor element in an acid bath, for example hydrofluoric acid. the free ends of the rod-like elements are reduced by etching or made peeling.

The pointed gaps 36 between the rod-like elements forming the conductor serve various functions. For example, the presence of the compartments 36 offers an area in which any debris from the fiber may fall instead of being pushed along by the fiber end to Furthermore, a fluid of the corresponding refractive index 7800208- "6 can be used at the interface to reduce light loss (conventional technique). Due to the shape of the gaps, the fluid of the corresponding refractive index can be forced around the sides of the opposite fiber ends and into the odd gaps without preventing the fiber ends from approaching each other, which occurs if the channel is circular and fits snugly around the fibers.

It should be noted that the conductor 22 can be used with different types of simple optical fibers (for example, plastic or glass-coated fibers).

The fibers 28 in the cable 27 are shown here clad with a material 42, for example glass, of a lower refractive index than the fiber body in order to reduce the light losses along the fiber.

Preferably, the glass is selected for the conductor element 22 so that it has the same refractive index as the fiber cladding, whereby low light loss is ensured in the connector.

Figs. 1 and 2 show the connector 24 for holding. the deflector 22 and for locking the ends 26 of the fibers 28 against each other in the conductor. In the embodiment shown in Figures 1 and 2, the connector 24 includes a pair of hermaphroditically mating connectors 50 and 52. The elements 50 and 527 are shown identically equal in size and shape.

Each element is elongate and includes a pair of ends 54 and 56 with a passage extending longitudinally therebetween and to the central axis of each element. The passage includes an enlarged, circular, cylindrical opening 59 at the end 54 which extends a considerable distance into the body of the element. The ends 56 of each element are in the form of at least two longitudinally extending fingers or claws 60. The claws 60 are distributed equally spaced around the periphery of the element from which they extend and define: between them a circular, cylindrical area. The circular, cylindrical region 62 includes an end wall 64 (Fig. 3) with a central aperture 66. The diameter of the central aperture is slightly larger than the outer diameter of the optical Eiber 28. Passage 58 includes a conically tapered portion between the enlarged opening 59 and the small diameter opening 66. The elements 50 and 52 are arranged to be connected to each other with the passages 58 coaxial by inserting the chlorine 60 of the element 50 between the claws 60 of the element 52. The claws of both elements have the same length and have curved cross-sections so that they form a cylindrical wall for a enclosed cavity 70, when the elements 50 and 52 completely. connected with each other.

The hollow rim 70 is arranged to receive and hold the charger member 22 am at the fiber ends therein. The cable 27 is a conventional cable of the type in which a single quaternary fiber is arranged within a protective sheath or sheath 72. To receive the sheath 72, the diameter of the enlarged opening 59 'in each of the elements 50 and 52 is slightly larger than the diameter 72 of the jacket.

In order to bring the fiber ends 26 securely into contact with each other end to end, when the fibers 28 are passed through the respective connecting connecting parts 50 and 52, each connecting connecting part comprises means for ensuring that the connected fiber end is in a desired, predetermined position, i.e. . extending, as shown in Figs. 1-4, a pair of longitudinally aligned apertures 74 through the opposite claws 60. An aperture 74 in each claw 60 extends half the distance from the rear wall 64, as was one of the 52 openings 74 of the element 74.

Accordingly, when the connector elements 50 and 52 are connected to each other as shown in Fig. 3, the four claws eo openings 74 will be aligned with each other in the longitudinal direction, and their axes extend radially into the center of the cavity 70 formed between the elements 50 and 52. .

Each aperture 74 serves as a viewing position for guiding the position of the fiber so that its end 26 aligns with the aperture. When each end 26 of the fibers to be joined together is aligned with the openings 74 of the respective connectors, and after these elements are locked together, the ends 26 of each fiber abut each other. To ensure a good connection regardless of minor defects in the surfaces of the fiber ends 26, it is preferred that the fiber ends be positioned so that their end surface extends slightly past the center of the opening 74, after which each fiber end extends slightly more than halfway in. consequently, when the elements 50 and 52 are locked to each other, the ends 26 tend to abut hard against each other and the fibers 22 to bend slightly within the tapered portion 68 of the passage 58, fig. 5. The bending of the fibers provides a load-bearing force which maintains intimate contact under pressure between the abutting fiber ends 26.

In order to maintain a secure connection mutually connected to each other in the fibers, a curved recess 26 is arranged in each of the claws 60, which recess is longitudinally aligned with and is adjacent to the openings 74. When the elements 50 and 52 are connected to each other, the recess 76 has an annular groove extending around the entire periphery of the completed shaft closure 74. A sealing O-ring 78 is then placed in the groove which covers the opening 74 and serves to hold together the elements 50 and 52 of the connector 24. The part of the recess 76 can be moved longitudinally from the position in which the openings 74 are covered by the O-ring 78.

Connection of a typical pair of optical fiber cables is as follows: The sheath 72 is removed from the end of the cables to be connected to expose the single optical fiber 28 in each cable.

Since the cable is of conventional construction, there is nothing between the sheath 72 and the optical fiber. Accordingly, for conventional cables, an epoxy binder is placed at the end of the sheath 72 of each cable so that the length of the optical fiber extending from the sheath is fixed. After the epoxy binder has dried, a cable end with the exposed fiber is inserted into the passage 58 of one element 50 of the connector 22, the sheath 72 of the cable being arranged in the enlarged opening 59 and the optical fiber extending through the tapered passage 58 and the small central opening 66. and into the cylindrical space 62 between the claws 60.

The fiber end 26 is placed longitudinally in the space 62 by looking through the opening 74 and moving the cable in the longitudinal direction until the fiber end 26 is seen to extend slightly beyond the center of the opening.

The cable is then locked in place by inserting a ett xi binder 80 between the cable sheath 72 and the wall of the enlarged opening 59. The end of the second fiber 28 of the second cable is placed and locked in the element 52 in an identical manner. When a removable connection is to be made, the channel in the conductor element 22 is suitably filled with a conventional oil of a refractive index corresponding to the refractive index of the optical fibers. In a permanent splice, the channel of the conductor element is suitably filled with an epoxy binder of a refractive index which corresponds to the refractive index of the optical fiber. The guide member 22 is then telescoped over one end of the first fiber by inserting said end into the enlarged opening 40 in the guide member 22. The guide member is then passed longitudinally relative to the fiber end so that the denifiable end located within the cavity 70 extends substantially its entire length in the conductor element 22. During this operation, the fiber end 26 will automatically adjust relative to the enlarged opening 40 in the conductor element 22 by interaction between the conductor element and the chlorine 60 of the element 52. The connector portion 52 is then connected to the element 50 by chlorine 60 is inserted between the chlorine 60 of the element 50. The end 26, which is locked at the element 50, is automatically adjusted relative to the enlarged opening 40 in the conductor element 22, which is already placed in the cavity 70 of the element 52 by the interaction between the chlorine 60 of the elements 50 and 52 .

The connector elements 50 and 52 are then moved relative to each other to the position shown in Fig. 3, after which the ends 26 of each of the fibers 28 abut each other and form a good joint, which has a low-loss optical transmission. The O-ring 78 previously positioned around the cylindrical portion of each connector member 50 or 52 is then rolled into position in the groove 76 so that the connector 24 is closed and locked. From the above it will be seen that the assembly 20 of conductors and connectors according to the invention allows fast and efficient disconnection end to end of a pair of simple optical fibers. The joint can be easily disconnected if desired by removing the O-ring 78 from the peripheral recess 76, thereby releasing both parts 50 and 52 of the connector 24.

The parts 50 and 572 of the connector are then separated, thereby disconnecting the fiber ends 26. The fiber ends can be reconnected to each other as described above.

It should also be clear that while the assembly according to the invention is particularly suitable for providing releasable connections, it can also be used for providing a permanent coupling or splicing between the fibers using a binder, for example an epoxy binder of a corresponding refractive index rather than a oil - with a corresponding refractive index in the conductor element 22 locking the fiber ends therein.

Another advantage of the preferred connector elements is the liermafroxy structure, which allows the two connector elements to be made identical. This lowers production and does not require extra time to make the connections while ensuring that a male and a female connection donor center are used. Another advantage of the connector element is the pair of elongate claws on each connector element, which facilitates the alignment of the conductor element channel with the fiber end. The parts of the claws which are beyond the setting openings receive the conductor element and at the same time adjust the channel of the conductor element in relation to the fiber end 26, when the claws are telescoped over the conductor element.

Fig. 7 shows in cross section an alternative embodiment of the connector 24 according to the invention. In the embodiment shown in Fig. 7, each connector element 50 and 52 comprises three longitudinally extending claws or fingers. The claws 90 are spaced equally around the periphery of the connector element 50, while the claws 92 are equally spaced around the periphery of the connector element 52. It can be seen that each block 92 wall is thicker than each block 90 wall. Consequently, when the connector members 50 and 52 are joined by interlacing their claws 90 and 92 (in the same manner as described above), they extend. each of the curved inner surface 94 of the claws 92 further into the cavity 70 than each of the curved inner surface 96 of the claws 90 '. The rod-like elements 30 of the conductor element 22 fit in the space between the immediately adjacent claws 92, thereby preventing the conductor element from 22 is rotated about its center axis when placed in the receptacle 70 of the connector 24.

The assembly 20 offers connection of only a pair of simple optical fibers, but it is clear that the conductor element 22 can be modified so that the set comprises a plurality of rod-shaped elements which are parallel to each other and connected along the abutting, longitudinal contact points, forming a plurality of spherical intermediate channels, each of which can receive a pair of abutting ends of simple optical fibers. The connector. 24 comprises, for receiving such a conductor element, a plurality of continuous passages, each in line with a pointed intermediate channel in the conductor element. The assembly designed in this way is suitable for co-coupling a plurality of pairs of simple optical fibers.

It should also be noted that the different rod-shaped elements do not have to have a mutually equal diameter. Since the diameters are different, both the gap hole size and the gap hole distance can accommodate a set or liner with a plurality of fibers. An alternative embodiment of the conductor element is shown in cross section 'in Fig. 8. The various rod-shaped glass elements are arranged inside an enclosing, hollow glass tube 100. The inner diameter of the tube corresponds to the outer diameter of the three joined, parallel rods 30. This construction allows the outer surface of the conductor element to form a regular cylinder and not only increases the strength of the conductor element assembly but also allows the conductor element to fit evenly in the holes 70 in the connector 24 in the claws. Another alternative embodiment of the conductor element is shown in FIG. The conductor element shown in Fig. 9 is arranged to receive optical fibers of extremely small diameter, i.e. when optical fibers as small as 0.08 mm or less in diameter are to be connected. The conductor element constructed according to Figs. 4-8 has an extremely small outer diameter and thereby lacks the structural piece.

In order to reinforce the structure as a whole, the conductor element comprises not only a plurality of parallel rods of a size for receiving the fiber ends but also a plurality of rods which are of substantially larger diameter and which receive the smaller conductor element in its inner channel.

The alternative embodiment shown in Fig. 9 thus comprises a plurality of glass rods 30, which form an outer conductor element, and a plurality of glass rods 132 of smaller diameter, which form the inner conductor element. The outer conductor element comprises three parallel rods 132, which are drawn after they have been heated, so that they form a conductor element similar to that shown at 22 in Fig. 2.

The inner conductor element formed by the rods 132 is likewise formed by three rods, which are heated and formed to provide a smaller conductor element, which is otherwise similar in construction to the outer conductor element. The channels formed in both the inner and the outer conductor element are widened at the ends in the same way as for the conductor element 22. The channel in the outer conductor element thus receives the inner conductor element formed by the rods 132 by telescoping the outer conductor element over the inner conductor element. The inner conductor element and the outer conductor element both have substantially the same length, the optical fiber 28 being fitted in the channel in the smaller conductor element formed by the rods 132. the conductor element in Fig. 9 is particularly suitable for interconnecting fibers of diameters as small as or less than 0.08 mn. Although for all of the embodiments shown and described here, the rod-shaped elements of the conductor elements are of solid construction, hollow cylindrical elements can also be used.

Claims (22)

7800208-6 16 PATENT REQUIREMENTS A control for use in providing an optical signal transmitting connection between the ends (26) of a pair of optical fibers (28), characterized by an integrating unit (22) of at least three side-by-side parallel glass elements (30, 132). ) of predetermined length and with cylindrical surface parts and fused together along longitudinal peripheral parts, in which unit the glass elements between them delimit a longitudinal, open-ended (40) channel (34), the cross section of which has a shape , which exhibits capes. (36) and having smooth surfaces for guiding the ends (26) of a pair of optical fibers (28) which are inserted into the channel until they come in close proximity to each other so as to form a good, optical signal transmitting joint. _ 2. A guide according to claim 1, characterized in that the glass elements consist of solid, preferably straight bars (30, 132). 3. A guide according to claim 1 or 2, characterized in that the open ends (40) of the channel (34) have a larger cross-sectional area than the part of the channel existing between the ends to facilitate insertion of an optical fiber (28). ) in the channel. I A _ _ _ * Control according to one of the preceding claims, characterized in that the refractive index of the glass elements (30, 132) is lower than the refractive index of a medium introduced into the channel (34). Guide according to one of the preceding claims, characterized in that the glass elements (30) are enclosed by a cylindrical tube (100). IN A guide according to any one of claims 1-4, characterized by at least three side-by-side, parallel cylindrical elements (130) of predetermined length and of a diameter substantially larger than the glass elements ( 132) diameter, and in contact with each other and interconnected along longitudinal peripheral parts, so that they form a channel between them, the cross section of which is in the form of a triangle with inwardly curved sides and in which the glass elements are placed. "V 7800208-6 Guide according to claim 6, characterized in that the cylindrical elements (130) are also formed of glass. IN Guide according to one of the preceding claims, characterized by a pair of connector elements (50, 52), each with its own continuous, longitudinally extending passage for a fiber (28) and terminated with an enlarged part (62) adjacent one of the connector elements. end (56), the connector elements being arranged to be interconnected with each other at said ends, so that their enlarged passage parts together form a longitudinally extending cavity (70) for the unit formed by the glass elements (30, 132). (22), and each passage adjacent the second end (54) of the connector elements has an enlarged opening (59) and adjacent the first-mentioned end a smaller opening (66), which smaller openings form entrances to the cavity, each passage tapering from its larger aperture to its smaller aperture, which is only slightly larger than the cross-sectional area of an optical fiber and is aligned with the channel (34) of the glass element unit for accurate positioning of a fiber extending through the passage and into the glass element unit, and position adjusting means (74) for ensuring that a fiber inserted into the passage extends into it to a predetermined extent, so that when the connector elements are connected the fiber ends are supported. against each other in the glass element unit in a good, optical signal transmitting joint. 7 A guide according to claim 8, characterized in that said position adjusting means is constituted by at least one opening (74) for visual inspection of the part of the cavity (70) in which fiber ends (26) are to be located . Control according to Claim 8 or 9, characterized in that the coupling between the connector elements (50, 52) is releasably lockable. 11.. Control according to claim 10, characterized in that the ends (56) of the connector elements (50, 52L which are arranged to be interconnected with each other, are of identical shape and form a hermaphroditic coupling. Control according to claim 11, characterized in that the coupling device elements of the connector elements (50, 52) coupling ends (56) each comprise at least two longitudinally extending claws (60, 90, 92), the claws of one element being located and held between the claws of the other element, when the elements are interconnected . A controller according to any one of claims 9 to 12, characterized by inspection openings (74) in each of kiornakeo, 90, 92). Control according to one of Claims 10 to 13, characterized in that the connector elements (50, 52) are arranged to be locked to one another by means of an O-ring (78) arranged around the claws (60, 90, 92). Guide according to claim 14, characterized in that each claw (60, 90, 92) has a recess (76) which, when the connector elements (50, 52) are interconnected, forms an annular groove for rings (78). > _ J Control according to one of Claims 8 to 15, characterized in that the enlarged opening (59) of each connector element (50, 52) is dimensioned to accommodate a sheathed cable (27) which contains an optical fiber (28). A guide according to any one of claims 12-16, characterized in that the claws (60, 90, 92) extend past the end (26) of an inserted optical fiber (28), so that the claws hold it between them. the glass element unit (22) in position for receiving the fiber ends. Control according to one of Claims 12 to 17, characterized in that each connector element (50, 52) has at least three claws (90, 92). Control according to claim 18, characterized in that the claws (92) of one connector element (52) have a larger transverse dimension than the claws (90) of the other connector element (50), and that the elements (30) of the glass element unit (22) peripherally located between the claws of larger transverse dimension, so that the glass shaft unit is prevented from rotating about its central axis; _ Guide according to one of the preceding claims, characterized in that the channel (34) of the glass element unit (22) has a central part with respect to the longitudinal direction of the channel, of approximately the same diameter as the fibers (28). for aligning their opposite ends (26) in line with each other. A method of manufacturing a guide according to claim 1, for use in providing an optical signal transmitting connection between the ends (26) of a pair of optical fibers (28), characterized in that at least three elongate glass elements (30, 132) have cylindrical surface portions in the hot state are arranged side by side in a set, in which they are parallel to each other and are in contact with each other along longitudinal parts, along which they are allowed to fuse with each other, so that they form an integrated unit (22) of fixed size and with a channel (34) having smooth surfaces between the glass elements, having a cross-sectional edge (36). A method according to claim 21, characterized in that the elongate glass elements (30, 132) in the form of rods, the cross-sectional areas of which are larger than their desired final cross-sectional areas, are arranged in said set and heated and drawn, so that their cross-sectional areas are reduced to predetermined size.