Devices and methods for terminating fiber optic cables

Abstract

A terminator for a fiber optic cable including at least one microstructured optical fiber comprises a hollow terminating member having a closed end and an opposite open end configured to cooperate with a cut end of the fiber optic cable, and a tubular collar having a first end in which the open end of the terminating member is received in a sealed manner and an opposite second end that receives the cut end of the fiber optic cable to cooperate with the open end of the terminating member, the second end having an inner diameter that is reducible to seal the tubular collar around the fiber optic cable.

Description

Technical Field

[0001] The present invention relates to a device and a method for terminating an optical fiber cable.

Background Art

[0002] Optical fibers are widely used for transmitting data carried by optical signals, and a plurality of fibers are used to carry separate data channels in parallel. For convenience and protection, a plurality of fibers are usually bundled together within a protective outer jacket to form an optical fiber cable.

[0003] Cables are installed in various environments to carry data between transmission locations and reception locations, over both long and short distances, and both underground and within buildings. Oftentimes, cables are deployed through ducts or pipes, and individual fibers are connected at each end of the cable by splicing to further cables or associated optical devices. Cable deployment and cable splicing require different techniques and may be performed by different individuals having the necessary skills. For example, a deployment person or team may install a cable through an underground duct from a data center to a building, and a splicing person or team takes over to pull the cable into the building and then processes the fibers within the cable. A delay may occur between these two stages, and therefore the deployment team is required to cut the deployed cable to the required length and store it ready to be handed over to the splicing team later.

[0004] To block contaminants, it is desirable to protect the ends of cables after cutting. This is usually appropriate, but is especially important when the cable contains fibers with voids within the fiber structure that can allow contaminants to enter. These include, but are not limited to, hollow core fibers and fibers with microstructure cladding. One way to avoid contamination is to seal the ends of individual fibers by heating and melting the glass that makes up the fiber to close the end. This can be done using fiber splicing machines, but these devices are costly and require power and are not typically performed by cable deployment teams. Alternatively, hot melt glue or UV-curing solutions may be applied to the fiber ends, but these also require specialized electrical equipment not normally used in cable deployment. In addition, the sealed fiber ends may be packaged in protective enclosures, which also requires equipment and skills. Furthermore, the number of fibers typically contained in a single cable makes these approaches unattractive. Handling a single fiber can take approximately 15 minutes, and a single cable may contain 4, 16, 32, or even more fibers. Furthermore, the packaged fiber ends are relatively bulky, and therefore, when applied to all fibers in a cable, the fiber ends that ultimately protrude from the cable jacket become cumbersome, long, and require careful handling, making this an unsuitable technique for further cable installation.

[0005] Accordingly, these approaches are not commonly adopted in practice, and cruder methods are used to protect the cut ends of fiber optic cables. Electrical insulating tape may be wrapped around the cable ends, but this only provides an ineffective barrier against contaminants. Cable manufacturers may supply plastic end caps intended to be placed over the cut cable ends, but these are small, easily lost items and provide only poor sealing.

[0006] Therefore, approaches to improve the sealing of optical fiber cable ends to protect microstructured fibers with internal voids are attracting attention. [Overview of the project]

[0007] The aspects and embodiments are described in the appended claims.

[0008] According to a first aspect of a particular embodiment described herein, a termination is provided for an optical fiber cable including at least one microstructured optical fiber, the termination comprising a hollow termination member having a closed end and an open end on the opposite side configured to cooperate with the cut end of the optical fiber cable, and a tubular collar, the tubular collar having a first end that receives the open end of the termination member in a manner that seals it, and a second end on the opposite side that receives the cut end of the optical fiber cable to cooperate with the open end of the termination member, the second end having an inner diameter that can be reduced to seal the tubular collar around the optical fiber cable.

[0009] According to a second aspect of a particular embodiment described herein, an optical fiber cable is provided having a cut end sealed by a terminator according to the first aspect.

[0010] According to a third aspect of a particular embodiment described herein, a kit is provided for forming a termination for an optical fiber cable comprising at least one microstructured optical fiber, the kit comprising a hollow termination member having a closed end and an open end on the opposite side configured to cooperate with the cut end of the optical fiber cable, and a tubular collar, the tubular collar having a first end that sealably receives the open end of the termination member and a second opposite end that receives the cut end of the optical fiber cable to cooperate with the open end of the termination member, the second end having an inner diameter that can be reduced to seal the tubular collar around the optical fiber cable.

[0011] A fourth aspect of a particular embodiment described herein provides a method for terminating an optical fiber cable containing at least one microstructured optical fiber, the method comprising the steps of cutting the optical fiber cable to create a cut end in which the optical fiber inside the optical fiber cable is exposed, and forming a sealed terminator according to the first aspect on the cut end of the optical fiber cable using a kit according to the third aspect.

[0012] A fifth aspect of a particular embodiment described herein provides a method for terminating an optical fiber cable including at least one microstructured optical fiber, the method comprising: cutting the optical fiber cable to create a cut end in which the optical fiber inside the optical fiber cable is exposed; positioning the cut end in cooperation with an open end of a hollow termination member, wherein the hollow termination member has a closed end opposite to the open end; and positioning a tubular collar having a first end and a second end, wherein the open end of the termination member is received in a manner in which it is sealed within the first end of the tubular collar, and the second end of the tubular collar opposite to the first end is sealed around the optical fiber cable.

[0013] These and further embodiments of specific embodiments are described in the appended independent and dependent claims. It will be understood that the features of the dependent claims may be combined with each other and with the features of the independent claims in combinations other than those expressly described in the claims. Furthermore, the approaches described herein are not limited to specific embodiments such as those described below, but encompass and intend to include any suitable combination of the features presented herein. For example, methods and devices relating to the approaches described herein, including one or more of the various features described below, may be provided as needed. [Brief explanation of the drawing]

[0014] For a further understanding of the present invention, the following accompanying drawings are referenced as examples to illustrate how the invention may be carried out. [Figure 1] This is a schematic longitudinal cross-sectional view of a first example of an optical fiber cable having a cut end to which embodiments of the present disclosure can be applied. [Figure 2] This is a schematic longitudinal cross-sectional view of a second example of an optical fiber cable having a cut end to which embodiments of the present disclosure can be applied. [Figure 3] This is a schematic longitudinal cross-sectional view of an exemplary terminator according to one embodiment of the present disclosure. [Figure 4] This is a schematic longitudinal section cross-sectional view of the terminator shown in Figure 3, which is fitted to the cut end of an optical fiber cable. [Figure 5] This is a schematic longitudinal partial cross-sectional view of a cut end of an optical fiber cable engaged with an exemplary termination member of a terminator according to one embodiment of the present disclosure. [Figure 6] This is a schematic longitudinal partial cross-sectional view of a cut end of an optical fiber cable engaged with another exemplary termination member of a terminator according to one embodiment of the present disclosure. [Figure 7] This is a schematic longitudinal partial cross-sectional view of a cut end of an optical fiber cable engaged with a termination member, which is a further exemplary of a termination device according to one embodiment of the present disclosure. [Figure 8] This is a schematic longitudinal partial cross-sectional view of another exemplary terminator according to one embodiment of the present disclosure, fitted to the cut end of an optical fiber cable. [Figure 9] This is a flowchart of the steps in an exemplary method for fitting a terminator according to an exemplary embodiment of the present disclosure to the cut end of an optical fiber cable. [Figure 10] This is a schematic longitudinal cross-sectional view of a further exemplary terminator according to one embodiment of the present disclosure. [Figure 11] This is a schematic longitudinal cross-sectional view of an exemplary terminator installed by another exemplary method of the present disclosure. [Modes for carrying out the invention]

[0015] Specific examples and embodiments of aspects and features are discussed / described herein. Some aspects and features of specific examples and embodiments may be implemented conventionally and, for the sake of brevity, are not discussed / described in detail. Therefore, it will be understood that aspects and features of devices and methods discussed herein but not described in detail may be implemented according to conventional techniques for implementing such aspects and features.

[0016] The devices and methods described herein are particularly applicable to optical fiber cables, which include one or more microstructured optical fibers, which are discussed in more detail below. The optical fiber cable comprises a plurality of optical fibers arranged in parallel in a bundle, the bundle being surrounded by an outer protective layer such as a jacket or sheath. The jacket may be formed from, for example, a polymer material, a low-smoke zero-halogen (LS0H or LSZH) material, or a stainless steel tubing. The jacket may contain only optical fibers, or in some examples, other elements may be included to make the cable more robust and resistant to damage. These may include a central reinforcing member (CSM) made from a high-tensile reinforcing material such as glass-reinforced plastic (GRP), fiber-reinforced plastic (FRP), stranded steel wire, nylon, or para-aramid yarn, extending along the length of the cable to withstand sharp bends and potential damage to the optical fibers, around which the optical fibers are arranged, bundled, wrapped, wound, or twisted, and one or more buffer layers of polymer material for fixing and protecting the individual or bundled fibers. Reinforcement members may also be used to surround the fibers, such as in the form of a layer between the fiber bundle and the jacket.

[0017] Optical fiber cables may comprise optical fibers of any type or design, and may include two or more types within a single cable. Generally, when the interior of a cable and fibers is exposed, it is desirable to reduce or prevent the ingress of contaminants through the cut or severed ends of the cable. More specifically, when a cable includes microstructured fibers with voids within the internal structure of the fibers, it is desirable to reduce the ingress of contaminants into individual fibers, as the presence of contaminants within the fibers can degrade optical performance. Parts of the cable may be removed to dispose of potentially contaminated ends, but this is wasteful and undesirable. Accordingly, this disclosure proposes devices and methods for terminating optical fiber cable ends to suppress and protect against fiber contamination, and more generally, cable contamination.

[0018] As described, when an optical fiber cable contains one or more microstructured fibers, protection of the exposed cable ends is particularly important. In this specification, the term is used to describe any optical fiber having one or more internal longitudinal voids, which may define or form part of the fiber core, fiber cladding, or both. More specifically, a microstructured fiber has an internal structure within the fiber material that includes an array or arrangement of pores, capillaries, or lumens, which extends along the length of the fiber parallel to the longitudinal axis and is defined within a material such as glass. The arrangement of pores may be called a microstructure, and typically, the microstructure forms at least part of the fiber cladding and may define a core, either additionally or otherwise.

[0019] The latter configuration can provide a hollow-core optical fiber, wherein a microstructured cladding surrounds a central hollow void or region that provides a light-guiding core. Microstructured capillaries are typically supported within a larger outer cladding tube made of glass. The propagation of light in air (or other gas or vacuum) enabled by the absence of a solid glass core reduces the proportion of guided light waves that propagate through glass compared to solid-core fibers, providing benefits such as increased propagation speed, reduced losses from both absorption and scattering, and reduced nonlinear interaction. Therefore, hollow-core fibers are very attractive for telecommunications applications, enabling near-light-speed data transmission with higher optical power and wider optical bandwidth in vacuum, and are relatively free from problems such as nonlinear thermo-optical effects that can affect light traveling in solid fibers. According to their light-guiding mechanisms, hollow-core fibers can be classified into two main classes or types: hollow-core photonic bandgap fibers (HCPBF, also referred to as hollow-core photonic crystal fiber (HCPCF)), and anti-resonant hollow-core fibers (AR-HCF or ARF). In HCPBF, the structured cladding region comprises a regular, closely packed array of many small glass capillaries, from which a central group is excluded to define a substantially circular hollow core. The periodicity of the cladding structure provides a substantially periodically structured refractive index, and thus provides a photonic bandgap effect that confines propagating light waves toward the core. In ARF, the structured cladding comprises far fewer larger glass capillaries or tubes, the structure lacks high periodicity, and thus the photonic bandgap effect is not significant, but it has a certain degree of periodicity on a larger scale because the tubes are evenly spaced. The structure provides anti-resonance that propagates wavelengths that do not resonate with the wall thickness of the cladding capillaries, and the cladding capillaries surround a central void or cavity, thereby providing the hollow core of the fiber and can correspond to anti-resonant guided optical modes.

[0020] This disclosure is applicable to all types of microstructured fibers, including two main classes of hollow core fibers and their associated subtypes, as well as other hollow core designs. Other examples include microstructured solid core fibers, where the void structure is provided only within a cladding region around a core defined within a solid material. The cladding may be an array of many capillaries to provide a photonic effect, or it may be a single ring of larger voids separated by a glass protrusion supporting a central solid core (a floating core fiber). All other designs of optical fibers having one or more internal voids are also applicable. Note that in the art, several terms are used redundantly for various classes of microstructured or “porous” fibers. For the purposes of this disclosure, the term “microstructured fiber” is intended to encompass all types having one or more longitudinal voids in their internal structure, and the terms “hollow core fiber” and “hollow core microstructured fiber” are intended to encompass all types of these fibers having the hollow cores described above. Any reference made by specific references to hollow core fibers should be understood as applicable to all microstructured fibers unless otherwise indicated by the context.

[0021] Structural voids in hollow core fibers and other microstructured fibers make these types of fibers particularly vulnerable to the ingress of contaminants that may enter the voids through the exposed, open end of the fiber, such as occurs when an optical fiber cable is cut. Contaminants can reduce fiber performance by causing optical loss. Although the contaminated end portion of the cable can be cut off, as noted above, this is particularly unattractive for hollow core fibers, which are more costly than conventional solid core fibers due to increased manufacturing complexity. Contaminants that are problematic for microstructured fibers, which can cause increased optical loss and attenuation when present, include particulate matter, water (vapor or liquid), and carbon dioxide. Water ingress can occur as longitudinal penetration through the open end of the cable or fiber, or as radial penetration where water vapor can be absorbed through the cable jacket and any accessories. The fiber protection techniques described herein can address both of these contamination pathways.

[0022] It is noted that the approach described herein is particularly applicable to cables comprising microstructured fibers, but may also be applied to cables having conventional solid core optical fibers.

[0023] Figure 1 shows a schematic longitudinal section of a first example of an optical fiber cable to which embodiments of the present disclosure are applicable. The optical fiber cable 10 is shown with its end or terminal portion cut or cut to give a cut end 12 having an end face 12a, through which the interior of the cable and, importantly, the interior of the microstructured fibers within the cable 10 are opened or exposed. In the field, installation or reconstruction of the optical fiber cable 10 may involve roughly and easily cutting the cable 10 using shears, scissors, a knife, or other cutting tool, and therefore the end face 12a is likely to be rough rather than clean or neat. The cable 10 comprises multiple optical fibers 14, represented by four fibers in this example, but may be any number such as two, eight, sixteen, twenty-four, forty-eight, or more or less. A cable having a single optical fiber is also not excluded. The optical fibers 14 may be of any type, including solid cores, hollow cores, or a mixture of multiple types within a single cable, but embodiments of the present invention are intended to be particularly beneficial for all kinds of microstructured fibers. Generally, each optical fiber 14 in the cable 10 comprises a core surrounded by cladding, the cladding being surrounded by a protective layer or covering. The optical fibers 14 are bundled together or bundled in a substantially parallel arrangement so as to extend longitudinally along the cable 10. The term “parallel” means only that the optical fibers 14 are aligned longitudinally and does not require that the individual fibers be straight; in actual cables, fibers may be twisted around each other or around other elements within the cable (not shown in this example). The optical fibers 14 may be in a single bundle or bundled into smaller bundles, in which case each bundle is bundled together. A buffer layer (not shown) may be included around all the fibers, around individual fibers, or around groups of multiple fibers.The cable 10 further comprises an outer protective layer or jacket 16 having a tubular shape that surrounds and tightly encloses the bundle of optical fibers 14, thereby protecting the optical fibers from external damaging factors and making the bundle more manageable and secure. The jacket 16 may be made of a polymer material such as polyethylene or polyvinyl chloride. The outer width or diameter of the jacket 16, and thus the entire cable 10, is typically in the range of 5 mm to 20 mm, for example, 8 mm to 10 mm, but this disclosure is applicable to all widths of the cable. In this example, the optical fiber cable 10 is cut along a single cut line, and therefore the jacket 16 and the fibers 14 are all terminated at the same end face 12a of the cut end 12.

[0024] Figure 2 shows a schematic longitudinal section view of a second example of an optical fiber cable to which embodiments of the present disclosure are applicable. As previously mentioned, the optical fiber cable 10, whose end portion is shown, comprises a plurality of optical fibers 14 fixed as a bundle within an outer jacket 16 (two are shown for illustrative purposes only). This example also includes a central reinforcing member or CSM 18, which is an elongated reinforcing element extending longitudinally along the length of the cable 10, in the center of the bundle of optical fibers 14, and the bundle of optical fibers 14 may be twisted or wound around the CSM 18. In this case as well, the optical fiber cable 10 has a cut end 12, but in this example, the cutting of the cable 10 is carried out by a more detailed process rather than a simple snip or chop with a blade. Each of the components is cut at a different position. The CSM 18 is cut at a position selected to give an end face 12b. The optical fiber 14 is cut shorter than the CSM 18, so the optical fiber 14 has an end 12c, and the end face 12b of the CSM protrudes beyond the end 12c. The jacket 12 is stripped from the optical fiber 14 over a short distance from the end 12c of the optical fiber 14 to the displaced end face 12a. Thus, the optical fiber 14 protrudes from the jacket 16, and the CSM 18 protrudes from the jacket 16 by a longer amount, thereby also protruding beyond the end 12c of the optical fiber 14.

[0025] Different configurations of the cut ends of the optical fiber cable, achieved by different cuts, can be terminated in different ways according to various embodiments of the disclosure, if desired. Other cuts are also possible, and the resulting cut ends can be terminated in a similar manner. For example, the optical fibers 14 and CSM 18 or other reinforcing members may be cut to substantially the same length, and the jacket 16 may be stripped so that the optical fibers 14 and CSM 18 protrude from the jacket by similar amounts.

[0026] Figure 3 shows a simplified longitudinal partial cross-sectional schematic view of a terminator according to an exemplary embodiment of the present disclosure. In this specification, a terminator is a device or apparatus that forms a closed or sealed termination at the end of an optical fiber cable, or is configured to form such a termination, for the purpose of preventing or restricting the ingress of contaminants into the interior of the optical fiber cable, specifically into the interior of the microstructured fibers within the optical fiber cable.

[0027] The termination 20 comprises two parts or components: a termination member 22 and a collar 30. The termination member 22 is a hollow element in the form of a container or cap, having one or more side walls 22a extending between a closed end 24 of the termination member 22 and an open end 26 of the termination member 22 opposite the closed end 24. In this example, the side walls 22a are straight cylindrical, and the closed end 24 is curved and does not form corners or edges with respect to the side walls 22a, so that the termination member 22 has an overall elongated tubular shape similar to a test tube. Other shapes of the termination member 22 are possible, but the present invention is not limited thereto. The open end 26 of the termination member 22 is configured to cooperate with the cut end 12 of the optical fiber cable 10. Various options for achieving this cooperation are envisioned, and in some examples, the cooperation may be an engagement between the cut end 12 of the cable and the open end 26 of the termination member. Engagement may be achieved by inserting or receiving at least a portion of the cut end 12 into the termination member 22. Cooperation is achieved by positioning these parts such that the closed end 24 of the termination member forms a cover or barrier between the exposed interior of the optical fiber cable 10 and fiber 14 at the cut end 12 and the external environment, thus preventing potential contaminating materials from entering the interior of the optical fiber cable 10 and fiber 14.

[0028] The collar 30 of the terminator 20 is provided for securing the terminator 20 to the optical fiber cable 10. Preferably, the securing is implemented to provide the optical fiber cable 10 with a sealed termination that can suppress or prevent the ingress of particulate, liquid, and gaseous contaminants. In such cases, the sealing provided by the terminator 20 may be considered to provide an hermetically sealed termination, but a smaller seal that does not completely block all gases, liquids, or smaller particles may also be beneficial, especially in situations where the terminator 20 is expected to be mated to the optical fiber cable 10 for only a short time.

[0029] The collar 30 is substantially tubular and comprises one or more side walls 30a extending between a first end 32 and a second end 34 opposite the first end 32. The side walls 30a preferably have a substantially cylindrical shape (circular cross-section) because this provides better coupling with the optical fiber cable 10, which also has a substantially circular cross-section. The first end 32 of the collar 30 receives the open end of the termination member 22 to seal it, thus forming a seal between the collar 30 and the termination member 22, typically at the boundary between the inner surface of the collar 30 and the outer surface of the termination member 22. The seal may be achieved by any convenient method, depending on the structure and configuration of the collar 30 (examples of which will be discussed further below) and the termination member 22. As a simple example, an adhesive may be applied between the opposing surfaces of the collar 30 and the termination member 22, or an O-ring, such as rubber, may be provided between the opposing surfaces to close any gaps that might normally exist and to provide some friction and tightness between the collar 30 and the termination member 22.

[0030] Alternatively, the termination unit 20 may be provided for use with the collar 30 and termination member 22 already sealed and coupled together. Alternatively, the collar 30 and termination member 22 may be provided as separate components within the kit, to be coupled together in the field if it is required to terminate the optical fiber cable 10. These two alternative configurations may be selected for convenience according to the structure and configuration chosen for the two components, as well as the method by which the sealing between them is provided.

[0031] The second end 34 of the collar 30 is an open end having an inner diameter D. The collar 30 is configured such that its inner diameter D can be reduced, in other words, it can be made smaller (its size reduced). The second end 34 is configured to receive the cut end 12 of the optical fiber cable 10 and engage with the open end 26 of the termination member 22, the cut end 12 being received in the direction indicated by the arrow R in Figure 3. In various examples, the cut end 12 may engage with the open end 26 by being inserted into the second end 34 of the collar 30 (the termination element 22 and the collar 30 are pre-connected together), or the cut end 12 may engage with the open end 26 before the collar is applied or positioned around both the cable 10 and the termination member 22. In either alternative configuration, when the cut end 12 of the cable 10 engages with the open end of the termination member 22, the inner diameter D of the second end 34 of the collar 30 is reduced so that it contacts the outer surface of the cable 10 and forms a seal of the collar 30 around the cable 10. The sealing of the collar 30 around the cable 10, along with the sealing between the first end 32 of the collar 30 and the termination member 22, provides a closed and sealed termination to the cut end 12 of the optical fiber cable 10, thereby protecting the cut end 12 from contamination.

[0032] To enable the placement of the collar 30 around the cable 10 (the collar 30 may or may not be engaged with the open end 26 of the termination member 22), such as by inserting the cable 10 into the second end 34 of the collar 30 (the collar 30 may or may not be already coupled to the termination member 22), or by sliding the second end 34 of the collar 30 over the cable 10, the inner diameter D of the second end 34 of the collar is initially greater than or equal to the outer or external diameter DC of the cable 10. It is preferable that the inner diameter D is greater than the outer diameter DC of the cable in order to facilitate the acceptance of the cut end 12 of the cable into the second end 34 of the collar 30 by providing some clearance space. For example, the inner diameter D may be about 1 mm, 2 mm, or 3 mm larger than the outer diameter DC, or may be greater in the range of 0.5 mm to 5 mm. It is sometimes preferable that this difference be small in order to minimize the amount by which the inner diameter D needs to be reduced in order to create a seal around the outer surface of the optical fiber cable 10.

[0033] Figure 4 shows a simplified longitudinal partial cross-sectional schematic of the terminator 20 of Figure 3 installed on the optical fiber cable 10. The cut end 12 of the cable 10 engages with the open end 26 of the termination member 22. In this example, this engagement involves inserting the cut end 12 into the open end 26 of the termination member 22 across the entire width of the cable 10 so that the end portion of the jacket 16 is received within the termination member 22. This is made possible by the fact that the open end 26 of the termination member 22 has an inner diameter di that is greater than or equal to the outer diameter DC of the cable 10. As shown, the inner diameter d is substantially the same as, or only slightly larger than, the outer diameter DC, so that the cable 10 fits snugly into the termination member 20, which can protect the cut end 12 and help hold the various components in a secure configuration.

[0034] Here, the inner diameter of the second end 34 of the collar 30 is reduced to DR, which matches the outer diameter DC of the cable 10, thereby sealing the collar 10 around the outer surface of the cable 10 as described above.

[0035] The various embodiments are not limited to any particular width or diameter of the cable. The various embodiments are applicable to both terrestrial and aerial configurations of fiber optic cables, which typically have outer diameters ranging from about 1 mm to 25 mm. Cables in the middle portion of this range are easier to handle in the context of implementing embodiments of the present invention, and their outer diameters are, for example, in the range of about 3 mm to 13 mm.

[0036] Figure 5 shows a simplified longitudinal partial cross-sectional schematic of an optical fiber cable 10 engaged with a termination member 22 according to a further example. The collar of the termination is omitted for clarity but may be one of the examples and embodiments described herein. In this example, the jacket 16 has been stripped from the end of the cable 10 so that the interior of the cable 10 protrudes beyond the jacket 16, so the optical fiber cable 10 has a cut end 12 prepared as in the example of Figure 2. In this example, the cable 10 is shown to contain only optical fibers 14, but may also contain reinforcing members and / or cushioning materials as described above. The cut end 12 of the cable 10 is engaged with the second end 26 of the termination member 22 by being inserted into the termination member so far that the protruding optical fibers 14 (and any other internal elements in the cable) are positioned within the termination member 22 (and surrounded by the side wall 22a), but not so far that the jacket 16 is also inserted. The jacket 16 remains outside the termination member 22. The inner diameter di of the open end 26 of the termination member 22 may be larger than the outer diameter DC of the cable 10, but this engagement by partial insertion may otherwise be arranged. As shown in Figure 5, the inner diameter di of the open end 26 of the termination member 22 is smaller than the outer diameter DC of the cable 10, but greater than or equal to the outer diameter df of the bundle of optical fibers 14 in the cable 10. In this way, the protruding end of the optical fiber 14 can be received into the termination member 22, but the jacket itself is too wide to be received into the termination member 22. Therefore, insertion of the cut end 12 into the termination member 22 is prevented by the edge of the open end 26 of the termination member 22 contacting the cut edge of the jacket 16. This approach can be useful, for example, to protect the fiber end from damage during mating with a terminator. If the protruding fiber 14 is cut to be shorter than the internal length of the termination member 22, the end of the fiber is protected from contact with the inside of the closed end 24 of the termination member. Otherwise, such contact may occur if there is nothing to limit the amount to which the cut end 12 of the cable 10 can be inserted into the termination member 22.

[0037] In the example in Figure 5, the termination member 22 is shown having substantially the same outer diameter or width de as the outer diameter DC of the cable 10. Although not essential, this arrangement can provide a relatively continuous and uninterrupted outer surface for the cable 10 to engage with the termination member 22. This can facilitate easier and simpler mating or application of the collar. Also, depending on the type of collar used, the outer surface of the mated termination may follow or reflect the surface beneath the cable 10 and the termination member 22, and thus may be similarly smooth and uninterrupted. This can facilitate the subsequent handling and operation of the terminated optical fiber cable.

[0038] The cable terminations proposed herein, as discussed herein, provide a sealed physical barrier between the open cable end and the surrounding environment to prevent contaminants from the environment from entering the fiber and cable. In addition, further protection and maintenance of the cable can be provided by configuring the termination to further remove contaminants that may already be present before the termination is installed. For example, contaminants may enter between the cutting of the cable and mating with the termination, or may be present from the manufacture of the cable or individual fibers. In particular, the inside of the cable or fiber may contain water (liquid or vapor) or carbon dioxide.

[0039] To remove these and other contaminants, the termination may include a material capable of absorbing contaminants from the atmosphere within the termination, including the end portion of the void within the fiber, when the termination is attached to the cable. It is preferable that one or more such absorbing materials can be contained within a hollow termination member. Thus, when the cut end of the cable is engaged with the termination member, the void within the termination member (enclosed by the closed end and sidewalls) is partially occupied by the absorbing material and at least a portion of the cut end of the cable.

[0040] Figure 6 shows a simplified schematic longitudinal section of an optical fiber cable 10 engaged with a termination member 22 in such an example. In this case as well, the collar of the termination is omitted for clarity. The cut end 12 of the cable 10 is engaged by being inserted into the open end 26 of the termination member 22 by a distance shorter than the internal length of the termination member 22. This leaves a space between the end face 12a of the cable 10 and the closed end 24 of the termination member 22. The termination member 22 contains within this space a certain amount of absorbent material 40 capable of absorbing contaminants from the optical fiber cable 10. For example, the absorbent material 40 may include silica gel capable of absorbing liquid water or water vapor that may be present at the end of the optical fiber cable 10. Additional or alternative absorbent materials may be included. For example, carbon dioxide can be removed from the optical fiber cable by amines such as monoethanolamine (MEA) and diethanolamine (DEA), or by calcium hydroxide.

[0041] The absorbent material 40 may take any convenient form. As shown in Figure 6, the absorbent material 40 may have a particulate form, as is common for silica gel. In such a case, it is useful that the particle size of the absorbent material is larger than any gap 28 that may exist between the outer surface of the engaging end 12 of the cable 10 and the inner surface of the termination member 22, so that the absorbent material is held in place within the termination member 22 by the presence of the end 12 of the cable 10 and is not likely to easily slip out of the termination member 22. For example, a typical particle size of about 2 mm for silica gel is perfectly suitable for achieving this effect.

[0042] If desired, other absorbent materials may be included to remove water and carbon dioxide or other pollutants. Two or more absorbent materials may also be included to remove two or more types of pollutants.

[0043] Terminators having one or more absorbent materials already present within the termination member may be provided for use. In other examples, absorbent materials may be provided as separate components that can be added to the termination member, for example, by convention, as needed and required, or when known contamination of the cable occurs. Any alternative configuration may be used in conjunction with alternative configurations of pre-assembled terminations (with the termination member and collar already joined together) and kits of separate termination members and collars for field assembly.

[0044] The amount of one or more absorbent materials provided may be selected in reference to the dimensions of the cable and termination, or in reference to the expected or suspected amount of contamination to be controlled. Relatively small amounts, for example, in the range of about 0.5 g to 20 g or about 1 g to 5 g, may be useful, but larger amounts may be used if preferred or required. The appropriate weight also depends on the density and effectiveness of the material.

[0045] Various configurations and materials are possible for forming the termination member. In the examples shown in Figures 3 to 6, the termination member is a single, integrated component and may be formed by molding or machining a suitable material such as a polymer. In some cases, it may be useful to be able to see the terminated cable end after the termination device is fitted. This can be achieved by forming the termination member from a transparent material such as a transparent polymer. In embodiments in which an absorbent material is included in the termination member, the transparent termination member can allow observation of the absorbent material instead of, or in addition to, the cut end of the cable. Some absorbent materials undergo a visible change in state when absorption occurs, and therefore the occurrence of absorption can be determined by a simple visual inspection of the termination device. For example, silica gel is available in a color-changing formulation, which changes color from a first color to a second color when water is absorbed.

[0046] In other examples, the termination member may comprise two or more parts or components rather than the single structure described above. These parts may be joined together to assemble the termination member before the termination is supplied for use (as a ready-made article or as a kit of multiple parts). Alternatively, the termination member may be supplied as an unassembled part or component, intended to be assembled in the field as part of the mating of the termination to the fiber optic cable.

[0047] The terminal member may be formed from two parts. The division between these two parts may be located anywhere convenient or preferred, but in a particular example, the two parts include a first part that provides a side wall or wall and a second part that provides a closed end.

[0048] Figure 7 shows a simplified longitudinal partial cross-sectional schematic of an optical fiber cable 10 engaged with a two-part termination member 22 in such an example. Similar to the example in Figure 5, the cable 10 is cut and the jacket is stripped to expose a bundle of protruding fibers 14, and the cable is engaged with the termination member 22 by inserting the protruding fibers 14 into the termination member until the edge of the open end 26 of the termination member 22 abuts against the cut end of the jacket 16. The termination member 22 comprises a first part having the form of a tube 42 with both ends open, in this example a straight cylindrical tube. One end of the tube 42 provides the open end 26 of the termination member 22. The second part of the termination member 22 comprises a plug or stopper 44 that can be inserted into the opposite end of the tube 42, thereby closing the opening at that end and thus forming the closed end 24 of the termination member 22. The plug 44 may engage with the pipe 42, or it may be held in place in any convenient way that provides a secure assembly of the two parts of the termination member 22. For example, a threaded connection may be provided, so that the plug 44 is threaded to the end of the pipe 42. Alternatively, a friction fit may be used, so that the plug 44 is pressed into the end of the pipe 42. Thus, the inside of the plug 44 may be shaped to allow engagement with the pipe 42. In the example shown, the plug 44 has an inwardly stepped profile to match the internal shape and size of the pipe 42, so that the plug 44 can be pressed into the end of the pipe 42. One or more flanges, etc., may be provided on the plug 44 or the pipe 42 to assist the friction fit. In this example, the outer surface of the plug 44 has a smoothly curved profile to avoid corners and to mimic the shape of the test tube in the aforementioned example of the termination element. Other shapes may be used if preferred.

[0049] Any suitable material may be used for the two components of the termination member. For example, these two components may be formed from polymer materials, as described above. The tube, in particular, may be made from a transparent material such as polymer to allow visual inspection of the engaged cut end of the cable. Alternatively, the tube and plug may be made from metal. For example, stainless steel tubing may be used as the tube, which is readily available and can be easily cut to the appropriate length required. Metal plugs provide a strong and robust end to terminations that may be vulnerable if the terminated cable is subjected to rough handling during subsequent installation processes, such as being pushed or pulled by duct or pipework. Plugs molded from polymer, rubber, or other plastic materials may be slightly deformable to facilitate mating with the tube.

[0050] Referring again to Figure 7, it should be noted that in this example, the optical fiber cable 10 includes a CSM 18 that is cut and protrudes beyond the end of the fiber 14. The inner surface 46 of the plug 44 is configured to engage with the cut end 12b of the CSM 18, either by molding or other means. This engagement allows the plug to be coupled or connected to the CSM 18, which not only helps to secure the termination member 22 in place but also provides reinforcement and overall strength to the terminated end of the cable 10. This engagement may be achieved by molding the inner surface to provide a contact surface that abuts against the end 12b of the CSM 18. If the termination member is supplied in two parts, glue may be applied to one or both of the contact surface and the CSM end 12b, so that when all parts of the cable and termination member are assembled together (which can be done in various orders as understood by those skilled in the art), the plug 44 is bonded to the end 12b of the CSM 18 and integrated with the cable 10. Other alternative configurations may be used to engage the CSM and plug. As another example, the inner surface 46 may be formed to have a central recess into which the end 12b of the CSM 18 is received when the termination member 22 is assembled with the cable 10.

[0051] Figure 7 shows a two-part termination member used with a cable cut so that the fiber bundle protrudes, although the two-part termination member may also be used with a cable cut to a simple plane, as shown in the example in Figure 6, omitting the engagement between the CSM and the plug. Similarly, the two-part termination member may be used with a cable without a CSM. The two-part termination member may also be used with absorbent material described in relation to Figure 6. Any such absorbent material may be added into the termination member through the open end after the termination member itself has been assembled, or it may be added through the opposite end of the tube before the tube is closed by the plug.

[0052] Similarly, the collar of the termination may be configured in multiple ways to provide the required features. Referring again to Figures 3 and 4, the collar 30a is shown very simply as a tube. While this is partly a representative example intended to convey the overall position of the collar as well as its relationship to the termination element and cable, it can also serve as a more accurate depiction of some embodiments in which the collar is a simple tube of a suitable material.

[0053] For example, the collar may comprise a tube made of a heat-shrinkable material such as polyolefin or polyester. The shrinkage of the heated tube reduces the inner diameter of the second end, sealing the collar around the cable. Several alternative configurations are suitable for using a heat-shrinkable collar. The termination may be provided as a kit consisting of multiple parts, the collar and the termination member being separate articles. The termination member is assembled with the cable by engaging the cut end of the cable with the open end of the termination member. The collar can then be slid over the termination member until it connects the cable and the termination member. The collar is shrunk by heating at least both ends to provide a seal with the termination member at the first end and a seal with the cable at the second end in a single assembly step. Alternatively, the first end of the collar may be pre-shrinked around the open end of the termination member to produce a pre-assembled termination into which the cut cable end can be inserted or not received, and then the second end of the collar is heated to seal the termination to the cable. Heat shrink collars can also be supplied as split tubes that open along one side, allowing them to be positioned around the cable and termination member from that side, which can be easier than sliding them over the end.

[0054] The collar may be formed from an elastic or rubberized material molded as a tube, and can be stretched or pulled over the cable and termination member. This elasticity allows the collar to be firmly pulled against the cable and termination member, forming a seal with these components.

[0055] Figure 8 shows a simplified longitudinal partial cross-sectional schematic view of a terminator 20 according to a further exemplary embodiment of the present disclosure, having a collar of a different design. The collar 30 comprises a substantially tubular member formed from, for example, a plastic or metal material. In contrast to the above example, in which the reductionable inner diameter of the collar is provided by the inherent properties of the material from which the collar is made, in this example, the reductionable inner diameter is achieved by a movable part, and therefore, mechanical adjustment by tool or by hand is required to reduce the inner diameter and seal the second end of the collar 30 around the cable 10.

[0056] As described above, the tubular collar 30 having a central hollow hole has a first end 32 that receives the open end of the termination member 22 in a manner that seals it. In this example, the sealing is provided by a first O-ring or grommet 36 fitted around the inner surface of the hole in the collar 30, which seals the gap between the inner surface of the collar 30 and the outer surface of the side wall of the termination member 22. Other methods may be used for sealing, which may be reversible, such as press-fit, friction-fit, or screw arrangement, or more permanent, such as gluing or other joining methods. It is assumed that any of these may be performed in advance to supply an already assembled termination, or, if the termination is supplied as a kit consisting of multiple parts, may be performed as part of the termination mating. The second end 34 of the collar 30 is provided with a second O-ring or grommet 38 fitted around the inner surface of the hole. The collar also comprises one or more movable parts 39 on which an O-ring 38 is positioned, and the movable parts 39 are configured to move inward (i.e., toward the cable 10) to tighten or compress the O-ring 38 against the outer surface of the inserted cable 10. This movement may be achieved by the operation of a rotating cuff on the outer surface of the collar, for example, by the rotation of which causes the inward movement of the movable part 39. Lever or ratchet action may also be used, and these and other methods will be apparent to those skilled in the art.

[0057] The mechanically movable collar may be configured such that the reduction in its inner diameter is reversible by reversing the movement of the movable part (for example, by reversing the rotation of a rotatable cuff), and thus the inner diameter can be increased again. This allows for easy and quick removal of the terminator 20 when access to the cut end of the cable 10 is needed again, and enables the reuse of the terminator.

[0058] The seal between the collar 30 and the termination member 22, shown in Figure 8 by the first O-ring 36, may also be configured for mechanical adjustment and operation. If the terminator is supplied as a kit consisting of multiple parts, this can facilitate the coupling between the collar 30 and the termination member 22 in the field. Alternatively, the collar 30 and the termination member 22 may be pre-coupled to provide a pre-assembled terminator, as already described.

[0059] In addition to protecting the fibers within a severed optical fiber cable from the intrusion of contaminating materials, the termination devices proposed herein also offer other advantages. In particular, the ends of the cables are also protected from damage caused by physical impacts during the subsequent installation of the cables through ducts, pipes, channels, etc. Furthermore, cables terminated by embodiments of the proposed termination devices are fully compatible with common techniques for installing cables in these locations.

[0060] The first technique involves drawing in or pulling the cable through a duct or the like. To achieve this pulling action, a wire is attached to the front end of the cable. This attachment is achieved by using a cable sock, which comprises an adjustable tubular grid of galvanized steel that fits onto the end of the cable and contracts to grip around the cable. The sock has a swivel joint at the end to which the wire is attached, thereby allowing the cable to be drawn in without twisting. The termination according to this proposal may be small, using embodiments that do not significantly increase the width or overall bulk of the cable end, for example, having the features of Figures 4, 5, and 7 (e.g., a termination member having an outer diameter similar to the outer diameter of the cable, and a collar formed as a tube capable of contracting its diameter through preferred material properties such as heat shrinkability or elasticity), in which case the cable sock configured to fit onto the exposed cable end is similarly suited to the terminated cable as described herein.

[0061] A second technique for installing cables, called blowing, involves pushing the cable through the duct by feeding it into the duct and injecting compressed air behind the leading end of the cable to propel it forward. In this case, too, a small termination is well suited to this application, and the use of termination members with metal ends can further protect the cable end from any impact that may occur when the cable end is pressed against the duct wall during blowing.

[0062] To facilitate these installation techniques, it is useful that the terminator is not excessively large compared to the cable width. For example, the overall length of the terminator may be in the range of approximately 1 to 20 times the outer diameter of the cable, more specifically, approximately 2 to 15 times the outer diameter of the cable. The maximum outer diameter of the terminator when mated to the cable may be larger than the outer diameter of the cable by approximately 5 mm to 15 mm, or, to enhance miniaturization, by a smaller range of approximately 0 mm to 3 mm. The overall external shape of the terminator may be such that its approximate cross-sectional profile is the same as or similar to that of the cross-sectional shape of the cable. For example, it is useful that a terminator with a substantially circular cross-section can be mated to a cable with a circular cross-section. However, these various parameters are not limiting, and the present invention may be implemented in other shapes and dimensions. The total length of the cable that may be considered useful for the terminator is also not limiting, and examples include cable installation lengths in the range of approximately 0.01 km to 30 km or approximately 0.05 km to 6 km.

[0063] As described, the terminator may be supplied already assembled for use. In this case, the terminator is mated by inserting the cut cable end into the collar and thus into the open end of the terminator, engaging the cut end with the terminator, and then reducing the inner diameter of the second end of the collar to seal the terminator around the cable. The terminator may or may not include absorbent material contained within the terminator. Alternatively, the terminator may be supplied as a kit consisting of multiple parts that are assembled into the terminator as part of the process of mating the terminator to the cable. The kit may comprise a collar and a single or separate terminator, or it may comprise a collar and a terminator as two (or more) parts that need to be joined together to make a terminator. In either case, the kit may further include absorbent material contained within the terminator. Alternatively, the kit may comprise a pre-assembled terminator and separate absorbent material to be added to the terminator if required. If the kit includes a terminator provided as a separate component, the terminator may be assembled by first connecting the collar and the termination member, and the assembled terminator is then mated to the cable. Alternatively, the cut cable end may first engage with the termination member (or, if supplied as two or more parts, one of them) before the collar is added.

[0064] Figure 9 shows a flowchart of steps in an exemplary method for terminating an optical fiber cable. The first step S1 of this method requires cutting the optical fiber cable to create a cut end, as in the various examples described above. In the second step S2, the cut end is engaged with the open end of a hollow termination member, which has a closed end on the opposite side. Then, in the third step S3, a tubular collar is positioned around the cable and the termination member, so that the first end of the collar is sealed around the open end of the termination member (in an alternative embodiment, the collar may be sealed around the termination member before the engagement of the cut end in step S1). In the final step S4, the inner diameter of the second end of the collar opposite the first end is reduced to seal the collar around the cable, thereby sealing the termination on the cut end of the cable.

[0065] In an alternative configuration, steps S1, S2, and S3 may be modified by first screwing the collar onto the cable (before or after the cable is cut and a cut end is formed), then engaging the cut end of the cable with the termination member, and then positioning the collar around the termination member by sealing. This is an option when the termination is provided as a kit consisting of multiple parts.

[0066] Figure 10 shows a schematic longitudinal section of another exemplary terminator 20 mated to a cable 10. The collar 30 of the terminator 20 is configured similarly to the example in Figure 8, and the termination member 22 includes absorbent material 40, although these embodiments are not essential. The example in Figure 10 differs from the previous example in that it further includes a valve 50 configured to provide a resealable airflow communication from the surrounding environment to the internal space of the terminator 20. The valve 50 allows air to be introduced into the interior of the terminator 20 when the terminator 20 is mated to the cut end of the cable 10, so that the inside of the terminator can be pressurized, in other words, to a pressure higher than the atmospheric pressure of the surrounding environment. This pressurization increases the sealing effect of the terminator by preventing liquids and gases from leaking over the seals between the collar and the cable and between the collar and the termination member. The quality of the seal may be slightly impaired due to factors such as temperature changes, which may allow the intrusion of ambient fluids, but this may be offset by the increased internal pressure within the terminator 20. This is particularly useful in situations where cable ends may have to be left unattended by the deployment team in contaminated locations such as outdoor cabinets or access chambers that may contain dirty water.

[0067] The valve 50 can be of any design or configuration suitable for engaging with a convenient means of introducing air (or another gas) into the terminator 20 through the valve 50, such as a hand pump (bicycle pump), foot pump, electric pump, or gas cartridge or gas cylinder. When in use, the terminator 20 is first fitted onto the cable 10 and one or more suitable seals are made (depending on the original configuration of the terminator 20), and then the internal air pressure can be increased by the valve 50. Figure 10 shows the valve 50 located on the wall of the collar 30, but it may be located on the wall of the termination member 22.

[0068] All of the embodiments and examples described above implement the cooperation between the cut end of the cable and the open end of the termination member as engagement, typically involving physical contact between the two parts and possibly including the insertion of at least a portion of the cable end into the termination member. The cooperation may be implemented in other ways, but still enables sealing of the cable end by providing the closed end of the termination member as a barrier that is sealed around the cable.

[0069] Figure 11 shows a schematic longitudinal cross-sectional view of an exemplary termination 20 fitted to a cable 10 such that the end face 12a of the cut end 12 of the cable 10 is spaced apart from the open end 26 of the termination member 22. The collar 30 of the termination 20 is configured similarly to the example in Figure 8, and the termination member 22 includes absorbent material 40, although these embodiments are not mandatory and other examples may be followed instead. Thus, the cut end 12 of the cable 10 is positioned to cooperate with the open end 26 of the termination member 22 by facing each other along the longitudinal direction defined by the length of the cable 10, while the collar 30 is sealed around the termination member 22 at its first end 32 and around the cable 10 at its second end 34, as described above. In the facing relationship, the cut end 12 and the open end 26 may be immediately adjacent to each other or in contact with each other. Alternatively, as shown in Figure 11, the cut end 12 and the open end 26 may be spaced apart from each other along the longitudinal direction.

[0070] Opposing cooperation can be achieved more clearly or more quickly than engagement, insertion, and cooperation, for example, when the outer diameter of the cable is greater than or equal to the inner diameter of the termination member.

[0071] To retain the absorbent material 40 (if included) within the termination member (to prevent leakage if the termination is disconnected from the cable), a transparent barrier 52 extending across the holes in the termination member 22 may be provided. The barrier 52 is configured to allow the passage of substances that the absorbent material 40 can absorb, so that substances can reach the absorbent material 40, but to prevent the absorbent material 40 from leaving the termination member 22. Any design having holes or openings smaller than the particle size of the absorbent material 40 will achieve this, and therefore the barrier may comprise, for example, a membrane, mesh, or grille. If the termination is supplied as a kit of multiple parts, the termination member may be supplied for use with the absorbent material already in place behind the barrier, or the termination member, absorbent material, and barrier may be supplied as separate parts to be assembled during the installation of the termination.

[0072] The various features of the termination device, including the color, the method of engagement between the cut cable end and the termination device, and the inclusion of materials capable of absorbing contaminants from within the cable, may be combined in any usable combination and are not limited to the specific combinations detailed and / or described herein. Furthermore, the termination device may find usefulness in other applications, such as terminating other types of cables, for example, electrical cables.

[0073] The various embodiments described herein are presented solely to aid in the understanding and teaching of the claimed features. These embodiments are provided only as representative examples of embodiments and are not exhaustive and / or exclusive. It should be understood that the advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein should not be considered as limitations to the scope of the invention as defined by the claims, or to equivalents thereof, and that other embodiments may be utilized and modified without departing from the scope of the claimed invention. Various embodiments of the invention may preferably include, consist of, or essentially consist of, appropriate combinations of disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not claimed herein but which may be claimed in the future.

Claims

1. A termination for an optical fiber cable containing at least one microstructured optical fiber, A hollow termination member having a closed end and an open end on the opposite side configured to cooperate with the cut end of the optical fiber cable, A tubular collar having a first end that is received in a manner that seals the open end of the termination member, and a second end on the opposite side that receives the cut end of the optical fiber cable in cooperation with the open end of the termination member, wherein the second end has an inner diameter that can be reduced to seal the tubular collar around the optical fiber cable, Equipped with, A terminator wherein the inner diameter of the open end of the termination member is smaller than the outer diameter of the jacket of the optical fiber cable and greater than or equal to the outer diameter of the optical fiber bundle within the optical fiber cable, thereby the termination member is configured to engage with the cut end of the optical fiber by inserting the end portion of the optical fiber bundle protruding from the jacket of the optical fiber cable into the open end of the termination member.

2. A terminator according to claim 1, wherein the open end of the terminator member is configured to engage with the cut end of the optical fiber cable, thereby cooperating with the cut end of the optical fiber cable.

3. A terminator according to claim 2, wherein the open end of the terminator member is configured to engage with the cut end of the optical fiber cable by inserting at least a portion of the cut end into the terminator member.

4. A terminator according to claim 1, wherein the cooperation between the open end of the terminator and the cut end of the optical fiber cable is configured such that the open end of the terminator faces the cut end of the optical fiber cable when the tubular collar is sealed around the optical fiber cable.

5. A terminator according to claim 4, wherein the cooperation includes the open end of the terminator member facing the cut end of the optical fiber cable and being spaced longitudinally apart from the cut end of the optical fiber cable.

6. A terminator according to claim 3, wherein the inner diameter of the open end of the terminator member is greater than or equal to the outer diameter of the jacket of the optical fiber cable, and the terminator member is configured to engage with the cut end of the optical fiber cable by inserting the end portion of the optical fiber cable into the open end of the terminator member.

7. A terminator according to claim 1, wherein the terminator member has an outer diameter substantially equal to the outer diameter of the jacket of the optical fiber cable.

8. A terminator according to any one of claims 1 to 7, wherein the tubular collar comprises a tube of heat-shrinkable material, so that heating to the second end reduces the inner diameter and seals the tubular collar around the optical fiber cable.

9. A terminator according to any one of claims 1 to 7, wherein the tubular collar is configured such that the inner diameter of the second end can be reduced by mechanical adjustment.

10. A terminator according to any one of claims 1 to 9, wherein the terminator member is a single article formed from a polymer material.

11. A terminator according to claim 10, wherein the polymer material is transparent.

12. A terminator according to claim 10 or 11, wherein the terminator member comprises one or more materials capable of absorbing contaminants from the atmosphere inside the terminator when the terminator is fitted to an optical fiber cable.

13. A terminator according to claim 12, wherein one or more of the materials are capable of absorbing water and / or carbon dioxide.

14. A terminator according to any one of claims 1 to 9, wherein the terminator member comprises a pipe and a plug that can be inserted into the end of the pipe so as to form the closed end of the terminator member.

15. A terminator according to claim 14, wherein the plug is shaped such that it engages with a central reinforcing member within the optical fiber cable when the termination member cooperates with the cut end of the optical fiber cable.

16. A terminator according to any one of claims 1 to 15, further comprising a valve capable of increasing the pressure inside the terminator after the terminator has been fitted onto an optical fiber cable.

17. An optical fiber cable having a cut end sealed by a terminator according to any one of claims 1 to 16.

18. A kit for forming a terminator for an optical fiber cable containing at least one microstructured optical fiber, A hollow termination member having a closed end and an open end on the opposite side configured to cooperate with the cut end of the optical fiber cable, A tubular collar having a first end that receives the open end of the termination member in a manner that can seal it, and a second end on the opposite side that receives the cut end of the optical fiber cable in cooperation with the open end of the termination member, wherein the second end has an inner diameter that can be reduced to seal the tubular collar around the optical fiber cable, Equipped with, The inner diameter of the open end of the termination member is smaller than the outer diameter of the jacket of the optical fiber cable, and greater than or equal to the outer diameter of the optical fiber bundle within the optical fiber cable, thereby the termination member is configured to engage with the cut end of the optical fiber by inserting the end portion of the optical fiber bundle protruding from the jacket of the optical fiber cable into the open end of the termination member.

19. A kit according to claim 18, wherein the tubular collar comprises a tube of heat-shrinkable material, so that heating to the second end reduces the inner diameter and seals the tubular collar around the optical fiber cable, and heating to the first end seals the tubular collar around the termination member.

20. A kit according to claim 18 or 19, wherein the tubular collar is configured such that the inner diameter of the second end can be reduced by mechanical adjustment.

21. A kit according to any one of claims 18 to 20, wherein the end member is a single article formed from a polymer material.

22. A kit according to claim 21, wherein the polymer material is transparent.

23. A kit according to claim 21 or 22, further comprising one or more absorbent materials for inclusion within the termination member, the one or more absorbent materials capable of absorbing contaminants from the atmosphere inside the termination when the termination is fitted to an optical fiber cable.

24. A kit according to claim 23, wherein one or more of the materials are capable of absorbing water and / or carbon dioxide.

25. A kit according to any one of claims 18 to 20, wherein the termination member comprises a tube and a plug that can be inserted into the end of the tube to form the closed end of the termination member.

26. A kit according to claim 25, wherein the plug is shaped such that it engages with a central reinforcing member within the optical fiber cable when the termination member cooperates with the cut end of the optical fiber cable.

27. A method for terminating an optical fiber cable containing at least one microstructured fiber, The steps include cutting the optical fiber cable to create a cut end in which the optical fiber inside the optical fiber cable is exposed, The steps of forming a terminator according to any one of claims 1 to 16, which is sealed to the cut end of the optical fiber cable, using the kit according to any one of claims 18 to 26, A method that includes this.

28. A method for terminating an optical fiber cable containing at least one microstructured fiber, The steps include cutting the optical fiber cable to create a cut end in which the optical fiber inside the optical fiber cable is exposed, A step of positioning the cut end so as to cooperate with the open end of a hollow end member, wherein the hollow end member has a closed end on the opposite side of the open end; The steps include: positioning a tubular collar having a first end and a second end such that the open end of the termination member is received in such a manner that it is sealed within the first end of the tubular collar, and the second end of the tubular collar opposite to the first end is sealed around the optical fiber cable; Includes, A method wherein the inner diameter of the open end of the termination member is smaller than the outer diameter of the jacket of the optical fiber cable and greater than or equal to the outer diameter of the optical fiber bundle within the optical fiber cable, thereby the termination member is configured to engage with the cut end of the optical fiber by inserting the end portion of the optical fiber bundle protruding from the jacket of the optical fiber cable into the open end of the termination member.

Images