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Title:
OPTICAL FIBRE MODULE
Document Type and Number:
WIPO Patent Application WO/2019/185643
Kind Code:
A1
Abstract:
An optical fibre module is described comprising an optical fibre assembly, a first connector plug-in assembly and a first connector housing. The optical fibre assembly comprises an optical fibre assembly optical fibre provided within a metal tube, the optical fibre assembly further comprising a first coupling means. The first connector plug-in assembly comprises a ferrule in which a first connector optical fibre is secured such that the first end of the first connector optical fibre is exposed at an end of the ferrule. The first connector housing comprises a second coupling means, wherein the optical fibre assembly and the first connector plug-in assembly are secured within the first connector housing using the first and second coupling means such that the first end of the first connector optical fibre is exposed within the first connector housing.

Inventors:
MARX, Benjamin (Schanzenstrasse 39 D9-D13, Cologne, 51063, DE)
HILL, Wieland (Schanzenstrasse 39 D9-D13, Cologne, 51063, DE)
RATH, Alexander (Schanzenstrasse 39 D9-D13, Cologne, 51063, DE)
BREUER, Stefan (Schanzenstrasse 39 D9-D13, Cologne, 51063, DE)
Application Number:
EP2019/057614
Publication Date:
October 03, 2019
Filing Date:
March 26, 2019
Export Citation:
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Assignee:
NKT PHOTONICS GMBH (Schanzenstrasse 39, D9-D13, Cologne, 51063, DE)
International Classes:
G02B6/38
Foreign References:
US20170227717A12017-08-10
US5280552A1994-01-18
US20160116683A12016-04-28
DE3112078A11982-10-07
JPH05303026A1993-11-16
JPH0540212A1993-02-19
US5082344A1992-01-21
Other References:
None
Attorney, Agent or Firm:
WHITING, Gary (5 Stirling House, Stirling RoadThe Surrey Research Park, Guildford Surrey GU2 7RF, GU2 7RF, GB)
Download PDF:
Claims:
Claim s

1. An optical fibre module comprising:

an optical fibre assembly comprising an optical fibre assembly optical fibre provided within a metal tube, the optical fibre assembly further comprising a first coupling means ;

a first connector plug-in assembly comprising a ferrule in which a first connector optical fibre is secured such that the first end of the first connector optical fibre is exposed at an end of the ferrule; and

a first connector housing into which the optical fibre assembly and the first connector plug-in assembly are provided, the first connector housing comprising a second coupling means, wherein the optical fibre assembly and the first connector plug-in assembly are secured within the first connector housing using the first and second coupling means such that the first end of the first connector optical fibre is exposed within the first connector housing.

2. An optical fibre module as claimed in claim 1, wherein the optical fibre assembly optical fibre and the first connector optical fibre are the same optical fibre. 3. An optical fibre module as claimed in claim 1, wherein the optical fibre assembly optical fibre and the first connector optical fibre are connected together by splicing or welding.

4. An optical fibre module as claimed in any one of claims 1 to 3 , wherein the ferrule of the first connector plug-in assembly provides a connection point to a first connector optical fibre of another optical fibre module.

5. An optical fibre module as claimed in claim 4, wherein the first connector housing further comprises a third coupling means, wherein the optical fibre module is configured to be connected to said another optical fibre module using the third coupling means.

6. An optical fibre module as claimed in any one of the preceding claims, further comprising a spring for spring loading the ferrule of the first connector plug-in assembly within the first connector housing.

7. An optical fibre module as claimed in any one of the preceding claims, wherein the first connector optical fibre is secured within the ferrule of the first connector plug in assembly by gluing. 8. An optical fibre module as claimed in any one of the preceding claims, wherein the optical fibre assembly and/ or the first connector plug-in assembly have one or more protrusions and/ or depressions for co-operating with one or more protrusions and/ or depressions of the first connector housing to locate the optical fibre assembly and/ or the first connector plug-in assembly within the connector housing.

9. An optical fibre module as claimed in any one of the preceding claims, wherein the first connector plug-in assembly includes a tube at least partially inserted within the first connector housing, wherein the optical fibre sensor element abuts said tube. 10. An optical fibre module as claimed in any one of the preceding claims, wherein the first connector plug-in assembly and/ or the first connector housing comprises one or more O-ring seals.

11. An optical fibre module as claimed in any one of the preceding claims, wherein the optical fibre module is a sensor module.

12. An optical fibre module as claimed in any one of the preceding claims, wherein the optical fibre module is a distributed temperature sensor. 13. An optical fibre module as claimed in any one of the preceding claims, further comprising:

a second optical fibre assembly comprising a second optical fibre assembly optical fibre provided within a metal tube, the second optical fibre assembly further comprising a coupling means;

a second connector plug-in assembly comprising a ferrule in which a second connector optical fibre is secured such that the first end of the second connector optical fibre is exposed at an end of the ferrule; and

a second connector housing into which the second optical fibre assembly and the second connector plug-in assembly are provided, wherein the second optical fibre assembly and the second connector plug-in assembly are secured within the second connector housing such that the first end of the second connector optical fibre is exposed within the second connector housing.

14. An optical fibre module as claimed in claim 13 , wherein the second optical fibre assembly optical fibre and the second connector optical fibre are the same optical fibre.

15. A system comprising a plurality of optical fibre modules as claimed in any one of the preceding claims, wherein each optical fibre module is connected to an adjacent optical fibre module of the plurality using the first connector housing of the respective optical fibre module.

16. A system as claimed in claim 15, further comprising a mating sleeve between the adjacent optical fibre modules, wherein the first connector housing of each optical fibre module is removably attachable to the mating sleeve.

17. A method comprising:

providing an optical fibre assembly comprising an optical fibre assembly optical fibre provided within a metal tube;

securing a first connector optical fibre within a ferrule of a first connector plug in assembly such that a first end of the first connector optical fibre is exposed at an end of the ferrule; and

securing the optical fibre assembly and the first connector plug-in assembly within a first connector housing using a first coupling means of the optical fibre assembly and a second coupling means of the first connector housing such that the first end of the connector optical fibre is exposed within the first connector housing.

18. A method as claimed in claim 17, further comprising securing the first connector optical fibre within the ferrule of the first connector plug-in assembly by gluing.

19. A methods as claimed in claim 17 or claim 18 , wherein the optical fibre assembly optical fibre and the first connector optical fibre are the same optical fibre.

20. A method as claimed in claim 17 or claim 18 , further comprising connecting together the optical fibre assembly optical fibre and the first connector optical fibre by splicing or welding.

21. A method of replacing one of a plurality of optical fibre modules, the method comprising:

detaching a first optical fibre module of the plurality of optical fibre modules from one or more adjacent optical fibre modules of the plurality; and

attaching a replacement optical fibre module to the one or more adjacent optical fibre modules of the plurality,

wherein the first optical fibre module and the replacement optical fibre module are optical fibre modules as claimed in any one of claims 1 to 14 or manufactured according to the method of any one of claims 17 to 20.

22. A method as claimed in claim 21, wherein the adjacent optical fibre modules are optical fibre modules as claimed in any one of claims 1 to 14 or manufactured according to the method of any one of claims 17 to 20.

Description:
Optical Fibre Module

Fie ld

This specification relates to an optical fibre module, such as an optical fibre sensor module, including a connector housing.

B ackground

Connectors can be provided to enable optical fibres to be connected, for example to other optical fibres. However, there remains a need for alternative connector arrangements, particular in the field of fibre in metal tube (FIMT) applications.

Sum m ary

In a first aspect, this specification describes an optical fibre module comprising: an optical fibre assembly comprising an optical fibre assembly optical fibre provided within a metal tube, the optical fibre assembly further comprising a first coupling means; a first connector plug-in assembly comprising a ferrule in which a first connector optical fibre is secured such that the first end of the first connector optical fibre is exposed at an end of the ferrule; and a first connector housing into which the optical fibre assembly and the first connector plug-in assembly are provided, the first connector housing comprising a second coupling means, wherein the optical fibre assembly and the first connector plug-in assembly are secured within the first connector housing using the first and second coupling means such that the first end of the first connector optical fibre is exposed within the first connector housing. The optical fibre module may be a sensor module. The optical fibre module may be a distributed temperature sensor.

In one form of the invention, the optical fibre assembly optical fibre and the first connector optical fibre are the same optical fibre. In an alternative form of the invention, the optical fibre assembly optical fibre and the first connector optical fibre are connected together, for example by splicing or welding.

The ferrule of the first connector plug-in assembly may provide a connection point to a first connector optical fibre of another optical fibre module. Further, the first connector housing may further comprise a third coupling means, wherein the optical fibre module is configured to be connected to said another optical fibre module using the third coupling means. The optical fibre module may comprise a spring for spring loading the ferrule of the first connector plug-in assembly within the first connector housing. The first connector optical fibre may be secured within the ferrule of the first connector plug-in assembly by gluing.

In some forms of the invention, the optical fibre assembly and/ or the first connector plug-in assembly may have one or more protrusions and/ or depressions for co- operating with one or more protrusions and/ or depressions of the first connector housing to locate the optical fibre assembly and/ or the first connector plug-in assembly within the connector housing.

The first connector plug-in assembly may include a tube (such as a distance tube) at least partially inserted within the first connector housing, wherein the optical fibre sensor element abuts said tube.

The first connector plug-in assembly and/ or the first connector housing may comprise one or more O-ring seals. The O-ring seal(s) may be configured to retain protective gel within the metal tube of the optical fibre assembly.

The optical fibre module may further comprise: a second optical fibre assembly comprising a second optical fibre assembly optical fibre provided within a metal tube, the second optical fibre assembly further comprising a coupling means; a second connector plug-in assembly comprising a ferrule in which a second connector optical fibre is secured such that the first end of the second connector optical fibre is exposed at an end of the ferrule; and a second connector housing into which the second optical fibre assembly and the second connector plug-in assembly are provided, wherein the second optical fibre assembly and the second connector plug-in assembly are secured within the second connector housing such that the first end of the second connector optical fibre is exposed within the second connector housing. The second optical fibre assembly optical fibre and the second connector optical fibre may be the same optical fibre. In a second aspect, this specification describes a system comprising a plurality of optical fibre modules as described with reference to the first aspect, wherein each optical fibre module is connected to an adjacent optical fibre module of the plurality using the first connector housing of the respective optical fibre module. The system may include a mating sleeve between the adjacent optical fibre modules, wherein the first connector housing of each optical fibre module is removably attachable to the mating sleeve.

In a third aspect, this specification describes a method comprising: providing an optical fibre assembly comprising an optical fibre assembly optical fibre provided within a metal tube; securing a first connector optical fibre within a ferrule of a first connector plug-in assembly such that a first end of the first connector optical fibre is exposed at an end of the ferrule; and securing the optical fibre assembly and the first connector plug-in assembly within a first connector housing using a first coupling means of the optical fibre assembly and a second coupling means of the first connector housing such that the first end of the connector optical fibre is exposed within the first connector housing. The optical fibre assembly optical fibre and the first connector optical fibre may be the same optical fibre. Alternatively, the optical fibre assembly optical fibre and the first connector optical fibre may be connected together, for example by splicing or welding. The method may further comprise securing the first connector optical fibre within the ferrule of the first connector plug-in assembly, for example by gluing.

In a fourth aspect, this specification describes a method of replacing one of a plurality of optical fibre modules, the method comprising: detaching a first optical fibre module of the plurality of optical fibre modules from one or more adjacent optical fibre modules of the plurality; and attaching a replacement optical fibre module to the one or more adjacent optical fibre modules of the plurality, wherein the first optical fibre module and the replacement optical fibre module are optical fibre modules as described with reference to the first aspect or manufactured according to the method as described with reference to the third aspect. The adjacent optical fibre modules may be optical fibre modules as described with reference to the first aspect or manufactured according to the method as described with reference to the third aspect.

In a fifth aspect, this specification describes an apparatus configured to perform any method as described with reference to the third or fourth aspects described above. Brief des cription of the drawings Example embodiments will now be described, by way of non-limiting examples, with reference to the following schematic drawings, in which :

Figure 1(a) is an exploded cross-section view of a connector housing according to an example embodiment;

Figure 1(b) is an exploded cross-section view of a connector plug-in assembly arrangement according to an example embodiment;

Figure 1(c) is an exploded cross-section view of an optical fibre assembly according to an example embodiment;

Figure 2 is a schematic cross-section of a partially assembled connector housing according to an example embodiment;

Figure 3 is a schematic cross-section of a partially assembled optical fibre and connector plug-in assembly arrangement according to an example embodiment;

Figure 4 is a schematic cross-section of a partially assembled optical fibre module according to an example embodiment;

Figure 5 is a schematic cross-section of an optical fibre module according to an example embodiment;

Figure 6 is a schematic cross-section of a pair of connected optical fibre modules according to an example embodiment;

Figure 7(a) is an exploded cross-section of a connector housing according to an example embodiment;

Figure 7(b) is an exploded cross-section of a connector plug-in assembly arrangement according to an example embodiment;

Figure 7(c) is an exploded cross-section of an optical fibre assembly according to an example embodiment;

Figure 8 is a schematic cross-section of a connector housing according to an example embodiment;

Figure 9 is a schematic cross-section of an optical fibre and connector plug-in assembly arrangement according to an example embodiment;

Figure 10 is a schematic cross-section of an optical fibre module according to an example embodiment;

Figure 11 shows a detail of part of the optical fibre module of Figure 10 ;

Figure 12 is a flowchart showing an algorithm in accordance with an example embodiment;

Figure 13 is a schematic view of a system in accordance with an example embodiment; Figure 14 is a flowchart showing an algorithm in accordance with an example embodiment; and

Figure 15 is a flowchart showing an algorithm in accordance with an example embodiment.

Detaile d de scription

Figure 1(a), 1(b) and 1(c) are exploded cross-section views of a connector housing 1, connector plug-in assembly arrangement 2 and optical fibre assembly 3 respectively of an optical fibre module according to an example embodiment.

The connector housing 1 of Figure 1(a) comprises a connector body 10 and a coupling means in the form of a connection nut 11. For fastening, the connector body 10 includes tool pads 12 (similar tool pads are likely to be provided on the connection nut 11). The connector body 10 comprises a nose 13 to allow the orientation of the connector with regard to a mating sleeve (as described below with reference to Figure 6). The connector housing 1 includes step 14 that may be used when coupling the connector housing to a similar connector housing of another optic fibre module (as described below with respect to Figure 6). The connector housing 1 also includes protrusions 15 for orienting the connector housing and/ or for preventing rotation of the connector housing (as discussed further below with reference to Figure 5). The connector body 10 has a frusto-conical mouth 16 and a coupling means in the form of an outer thread 17. The outer thread is used for mounting the connector housing to an optical fibre assembly, as described further below with reference to Figure 5. The connector plug-in assembly arrangement 2 of Figure 1(b) comprises a fibre optic ferrule 21, a pin holder 22, a ring-groove 23, an O-ring seal 24, a spring 25 and a distance sleeve 26.

The optical fibre assembly 3 of Figure 1(c) comprises an optical fibre 30 , a metal tube 31, a coupling means in the form of a coupling nut 32, a front ferrule 33 and a back ferrule 34. The optical fibre 30 and metal tube 31 collectively form a fibre in metal tube (FIMT) arrangement. The inside of the metal tube 31 may be lined with a gel for protecting the optical fibre 30. Figure 2 is a schematic cross-section of a partially assembled connector housing, indicated generally by the reference numeral 4, according to an example embodiment. As shown in Figure 2, the connection nut 11 of the connector housing is pushed over the tool pads 12.

Figure 3 is a schematic cross-section of a partially assembled optical fibre and connector plug-in assembly arrangement, indicated generally by the reference numeral 5, according to an example embodiment. As shown in Figure 3 , the fibre optic ferrule 21 is mounted inside the pin holder 22 and the O-ring seal 24 is mounted within the ring groove 23. As also shown in Figure 3 , the front ferrule 33 and back ferrule 34 of the optical fibre assembly 3 are slipped over the metal tube 31 of the FIMT device. The spring 25 is threaded over the optical fibre 30. In the arrangement 5, the optical fibre 30 has not (yet) been inserted into the optical fibre ferrule 21.

Figure 4 is a schematic cross-section of a partially assembled optical fibre module, indicated generally by the reference numeral 6, according to an example embodiment.

In the optical fibre module 6, the optical fibre 30 is inserted into the optical fibre ferrule 21 (through a small hole in the optical fibre ferrule). The fibre 30 may, for example, be secured within the ferrule 21 by gluing. The optical fibre ferrule 21 may, for example, be a metal or ceramic ferrule.

The connector plug-in assembly arrangement 2 (including the fibre optic ferrule 21, pin holder 22, ring-groove 23, O-ring seal 24, spring 25 and distance sleeve 26) is mounted within the connector body 10 of the connector housing 1.

The distance sleeve 26 may be slotted in the axial direction to allow placement of the distance sleeve over the optical fibre 30. The distance sleeve may have a diameter slightly larger than the diameter of the inner bore of the connector body 10. During assembly, the distance sleeve 26 is positioned over the optical fibre 30 between the spring 25 and the metal tube 31. The spring and distance sleeve are inserted into the connector body 10 , where the distance tube 26 is tightly fitted in place. The distance sleeve 26 pushes against the spring 25. The fibre optic ferrule 21 and pin holder 22 are thereby urged towards the front face of the connector housing 1 by the action of the spring 25.

As shown in Figure 4, a first end of the optical fibre 30 is exposed at the end of the ferrule 21. The exposed optical fibre 30 can be polished in a manner well known in the art. Such polishing can be performed in the field (for example, on assembly of the optical fibre module) or when manufacturing an assembled optical fibre module.

Figure 5 is a schematic cross-section of an optical fibre module, indicated generally by the reference numeral 7, according to an example embodiment. The coupling nut 32 of the optical fibre assembly is mounted to the outer thread 17 of the connector body 10 (for example by screwing the optical fibre assembly 3 onto the connector body assembly 1) The exposed optical fibre 30 may be polished after attaching the optical fibre module 30 to the connector housing 1. (Although a screw thread arrangement is shown for the connection of the optical fibre module 30 to the connector housing 1, alternative fixing arrangements (such as plugs or bayonet fittings) could be provided.)

As shown in Figure 5, the metal tube 31 abuts the distance sleeve 26. Similarly, distance sleeve 26 abuts the spring 25. The ferrule 21 is moveable within the connector body 10 and is spring loaded by the spring 25.

As shown in Figure 5, the back ferrule 34 of the optical fibre assembly 3 is conveniently shaped for mounting to the frusto-conical mouth 16 of the connector housing 1. This may help to provide an advantageous sealing. (It should be noted that the metal tube 31 may include a protective gel.) Of course, other configurations could be provided in alternative embodiments.

As shown in the detail of Figure 5, the protrusions 15 of the connector housing 1 are provided for orienting the connector housing and/ or for preventing rotation of the connector housing.

Figure 6 is a schematic cross-section of a pair of connected optical fibre modules, indicated generally by the reference numeral 70 , according to an example embodiment. The connected optical fibre modules 70 include a first optical fibre module 7a and a second optical fibre module 7b, each similar to the optical fibre module 7 described above. As shown in Figure 6, the first optical fibre module 7a includes an optical fibre 30a mounted within a metal tube 3 la, a ferrule 2 la and a coupling nut lla. Similarly, the second optical fibre module 7b includes an optical fibre 30b within a metal tube 3 lb, a ferrule 2lb and a coupling nut llb. The first and second optical fibre modules 7a and 7b are connected using a mating sleeve 40. As shown in Figure 6, the first optical fibre module 7a is connected to the mating sleeve using the connection nut lla and the second optical fibre module 7b is connected to the mating sleeve using the connection nut llb. A sealing material (e.g. Teflon film) may be provided between the connection nuts lla and llb and the mating sleeve 40.

The mating sleeve 40 includes an inner bore 41 in which the ferrules 2la and 2lb of the respective optical fibre modules are received, thereby providing a contact between the ends of the optical fibres 30a and 30b. The mating sleeve 40 includes one or more notches 42 to orient the connectors and one or more O-ring grooves equipped with O- ring seals 43. The mating sleeve also includes threads 44 for attachment to the connection nuts lla and llb (e.g. by screwing, although alternatives fixing

arrangements (such as plugs or bayonet fittings) could be provided).

The ferrules 2 la and 2 lb are spring loaded within the first and second optical fibre modules 7a and 7b respectively. The ferrules can be pushed inwards against the biasing of the relevant springs. The springs also function to push the ferrules (and hence the polished ends of the optical fibres 30a and 30b) into contact with one another.

The mating sleeve 40 provides one example arrangement for mating two optical fibre modules together. Other arrangements are possible. In some forms of the invention, optical fibres modules such as the modules 7a and 7b are provided in a fully assembled form and are coupled together on-site. In other forms of the invention, the optical fibre modules are at least partially assembled on site.

The optical fibres modules 7, 7a and 7b described above provide one example optical fibre module configuration. A number of variants and alternatives are possible.

Figure 7(a), 7(b) and 7(c) are exploded cross-section views of a connector housing 101, connector plug-in assembly arrangement 102 and optical fibre assembly 103 of an optical fibre module according to an example embodiment. The connector housing 101, connector plug-in assembly arrangement 102 and optical fibre assembly 103 have a number of similarities to the connector housing 1, connector plug-in assembly arrangement 2 and optical fibre assembly 3 described above. The connector housing 101 of Figure 7(a) comprises a connector body 110 and a coupling means in the form of a connection nut 111, the connector body having tool pads 112. The connector body 110 comprises a nose 113 to allow the orientation of the connector with regard to a mating sleeve (such as the mating sleeve 40 described above with reference to Figure 6). The connector housing 101 includes step 114 and includes protrusions 115 for orienting the connector housing and/ or for preventing rotation of the connector housing. The connector body 110 has a frusto-conical mouth and a coupling means in the form of an outer thread 117. The outer thread is used for mounting the connector housing to an optical fibre assembly. Accordingly, the connector housing 101 has many similarities with the connector housing 1 described above.

As shown in Figure 7(a), the connector housing 101 includes a spring 125 provided between a first distance tube 116 and a second distance tube 126. As discussed further below, the spring 125 and first and second distance tubes 116 and 126 have similar functions to the spring 25 and distance tube 26 of the connector plug-in assembly arrangement 2 described above.

The connector plug-in assembly arrangement 102 of Figure 7(b) comprises a fibre optic ferrule 121, a pin holder 122, a ring-groove 123 and an O-ring seal 124 that are similar to the fibre optic ferrule 21, pin holder 22, ring-groove 23 and O-ring seal 24 described above. The connector plug-in assembly arrangement 102 further comprises a further ferrule 127 and a tape arrangement 129. A connector optical fibre 128 is provided within both the fibre optic ferrule 121 and the further ferrule 127. The connector optical fibre 128 may be fixed in the ferrule 121 (e.g. by gluing) before being welded or spliced (or otherwise attached) to the optical fibre assembly 103 (described in detail below). This may enable field installations without the need for polishing the connector optical fibre 128 in the field. In the connector plug-in assembly arrangement 102, the connector optical fibre 128 may be fixed within the further ferrule 127. The connector optical fibre 128 could, for example, be a piece of tight buffer fibre, where the buffer is stripped at the front and at the back. The tape arrangement 129 may have a front part in the form of a tube that can be latched onto the pin holder 122. The tape arrangement 129 may also have a back part comprising two wings which can be opened. On both wings there may be a tape or soft formable adhesive frlm. When the wings of the back part of the tape arrangement are pressed against each other, a fibre splice (described further below) is embedded and protected in the adhesive soft material.

The optical fibre assembly 103 of Figure 7(c) comprises an optical fibre 130 , a metal tube 131, a coupling means in the form of a coupling nut 132, a front ferrule 133 and a back ferrule 134. The inside of the metal tube 131 may be lined with a gel for protecting the optical fibre 130. The optical fibre 130 and metal tube 131 collectively form a fibre in metal tube (FIMT) arrangement. The optical fibre assembly 103 is therefore very similar to (and may be identical to) the assembly 3 described above.

Figure 8 is a schematic cross-section of a partially assembled connector housing, indicated generally by the reference numeral 104, according to an example

embodiment. As shown in Figure 8 , the connection nut 111 of the connector housing 1 is pushed over the tool pads 112. Further, the first distance tube 116, spring 125 and second distance tube 126 are inserted within the connector body 110.

Figure 9 is a schematic cross-section of a partially assembled optical fibre and connector plug-in assembly arrangement, indicated generally by the reference numeral 105, according to an example embodiment. As shown in Figure 9, the fibre optic ferrule 121 is mounted inside the pin holder 122 and the O-ring seal 124 is mounted within the ring groove 123. The further ferrule 127 is also mounted inside both the pin holder 122 and the tape arrangement 129. When the further ferrule 127 is mounted inside the pin holder 122, the connector optical fibre 128 may extend out of the ferrule 121 and require polishing. In some embodiments, it may be advantageous to polish the connector optical fibre before the plug-in assembly arrangement 102 is mounted in the connector housing 101. As also shown in Figure 9, the front ferrule 133 and back ferrule 134 of the optical fibre assembly 103 are slipped over the metal tube 131 of the FIMT device. In the

arrangement 105, the optical fibre assembly optical fibre 130 is connected (e.g. through splicing) to the connector optical fibre 128 within the tape element 129. After splicing of the optical fibre assembly optical fibre 130 to the connector optical fibre 128 , the tape element 129 is brought into its final position by pressing the wings of the tape element 129 onto the optical fibre 130. Figure 10 is a schematic cross-section of an optical fibre module, indicated generally by the reference numeral 107, according to an example embodiment. The coupling nut 132 of the optical fibre assembly is attached to the outer thread 117 of the connector body 110 (for example by screwing the optical fibre assembly 103 onto the connector housing 101). The connector optical fibre 128 may initially be exposed beyond the ferrule 121 and may be polished after attaching the optical fibre assembly 103 to the connector body assembly 101. (Although, as discussed above, it may be preferred to polish the connector optical fibre 128 before attaching the optical fibre assembly 103 to the connector body assembly 101. Indeed the connector optical fibre 128 may be fixed in the ferrule 121 before being welded or spliced (or otherwise attached) to the optical fibre assembly 103, thereby enabling field installations without the need for polishing the connector optical fibre 128 in the field.) Although a screw thread arrangement is shown for the connection of the optical fibre assembly 103 to the connector housing 101, alternative fixing arrangements (such as plugs or bayonet fittings) could be provided.

As shown in Figure 10 , the metal tube 131 abuts the second distance sleeve 126. As noted above, the spring 125 is provided between the first and second distance sleeves 116 and 126. The ferrule 121 is moveable within the connector body 110 and is spring loaded by the spring 125. When the plug-in assembly module 102 is latched into the distance sleeve 116, the distance sleeve 116 is spring loaded and so the complete plug-on assembly 102 (including ferrule 121) is spring loaded.

As shown in the detail part A, the connector housing may include protrusions for orienting the connector housing and/ or for preventing rotation of the connector housing. Figure 11 shows a detail of part of an optical fibre module, indicated generally by the reference numeral 108 , according to an example embodiment. The detail 108 includes details of the coupling between the connector housing 101, the connector plug in assembly arrangement 102 and the optical fibre assembly 103. As shown in Figure 11, the metal tube 131 is pushed against the second distance tube 126. An insertion piece 140 is provided to give stability to the overall device. In the optical fibre module 108 , the connector housing 101 is modified to feature an inner bore and an outer bore, forming a shoulder 142. The outer bore has the diameter of the metal tube 131. The second distance sleeve 126 is inserted with the complete connector plug-in assembly arrangement 102 into the inner bore. Then the insertion piece 140 , which has an outer diameter larger than the inner bore, is inserted into the connector body 101. The insertion piece 140 rests on shoulder 142 in the connector body. The insertion piece 140 is formed such that the second distance sleeve 126 is prevented from slipping into the metal tube 131. The metal tube 131 rests also on the insertion piece 140 , but the shoulder 142 stops any force so that the metal tube 131 cannot be pressed into the connector body. In this way the metal tube 131 cannot be inserted further than the shoulder 142, either by accident or external forces. Furthermore, the spring load is constant. The insertion piece 140 is slipped over the fibre 130 in the early steps of installation. The optical fibre module 107 has many similarities with the optical fibre module 7 described above. For example, the optical fibre module 107 can be coupled to another optical fibre module using a mating sleeve 40 as described above with reference to Figure 6. Note that the optical fibre module 107 could be connected to another optical fibre module 107, to an optical fibre module 7, or to another variant of such optical fibre modules.

Figure 12 is a flowchart showing an algorithm, indicated generally by the reference numeral 200 , in accordance with an example embodiment. The algorithm 200 starts at operation 200 where an optical fibre assembly (such as the assemblies 3 and 103 described above) is provided. Next, at operation 204, a connector optical fibre is secure within a ferrule of a connector plug-in assembly (such as the assemblies 2 and 102), for example by gluing. Finally, at operation 206, the optical fibre assembly and the connector plug-in assembly are secured within a connector housing (such as the housings 1 and 101).

Figure 13 is a schematic view of a system, indicated generally by the reference numeral 210 , in accordance with an example embodiment. The system 210 comprises a first optical fibre module 220 , a second optical fibre module 222 and a third optical fibre module 224 (those optical fibre modules take the form of the modules 7 or 107 described above). The first and second optical fibre modules are coupled by a first mating sleeve 214. Similarly, the second and third optical fibre modules are coupled by a second mating sleeve 216. The mating sleeves may take the form of the mating sleeve 40 described above. Terminal modules 212 and 218 are provided at either end of the system 210. The system 210 may be used as a sensor arrangement comprising multiple optical fibre modules (three are shown in the system 210 , but any number of optical fibre modules could be provided).

Figure 14 is a flowchart showing an algorithm, indicated generally by the reference numeral 230 , in accordance with an example embodiment. The algorithm 230 starts at operation 232 where a first optical fibre module (such as one of the optical fibre modules 220 , 222 and 224 described above) is detached (for example, by means of the mating sleeves). Then, at operation 234, a replacement optical fibre module is attached (again, for example, by means of the mating sleeves).

Figure 15 is a flowchart showing an algorithm, indicated generally by the reference numeral 240 , in accordance with an example embodiment. The algorithm 240 enables two optical fibre modules, such as the modules 220 , 222 and 224 described above, to be connected together using, for example, a mating sleeve 40 as discussed above.

The algorithm 240 starts at operation 242, where connection nuts of adjacent optical fibre modules are loosened.

Next, at operation 244, the connector housings 1 or 101 of the each of the optical fibre modules are oriented to a mating sleeve (such as the mounting sleeves 40 , 214 or 216) and to each other. Once aligned, the connector housings are screwed to the mating sleeve (operation 246) before the respective connection nuts are tightened (operation 248). The algorithm 240 can be particularly advantageous if, for example, the noses 13 or 113 of the respective fibre modules are not aligned.

Many further modifications and variations will be evidence to those skilled in the art, that fall within the scope of the following claims.