Indexing architecture including a fan-out arrangement

The present disclosure relates to fiber optic components and structures for use in building fiber optic networks using an indexing architecture. In certain examples, fan-out structures are used.

TECHNICAL FIELD

The present disclosure relates generally to equipment for fiber optic communications networks. More particularly, the present disclosure relates to fiber optic networks including indexing architectures and fan-outs.

BACKGROUND

Optical networks are becoming increasingly prevalent in part because service providers want to deliver high bandwidth communication capabilities to customers. As the demand for optical networks increases, there is a need to extend fiber optic networks closer to the edge (i.e., closer to subscriber locations). In this regard, there is a need for cost-effective architectures for extending fiber optic networks. One example of a cost-effective architecture is an indexing architecture. Example indexing architectures are disclosed by PCT Int'l Publication No. WO 2014/190281.

SUMMARY

Aspects of the present disclosure relate to fiber optic networks having indexing architectures that utilize fan-outs.

Other aspects of the present disclosure relate to fiber optic networks having indexing architectures with indexing components adapted for indexing a relatively large number of optical fibers (e.g., greater than 12 fibers, or greater than 18 fibers, or greater than or equal to 24 optical fibers).

Another aspect of the present disclosure relates to indexing components that can be daisy-chained (e.g., coupled end-to-end) together to form an indexing architecture. In one example, each indexing component can include separate first multi-fiber connection interfaces defining a first set of sequential fiber positions defined by a combination of the first multi-fiber connection interfaces such that the sequential fiber positions are sequenced across the first multi-fiber connection interfaces. The indexing component can also include separate second multi-fiber connection interfaces defining a second set of sequential fiber positions defined by a combination of the second multi-fiber connection interfaces such that the sequential fiber positions are sequenced across the second multi-fiber connection interfaces. The indexing component also includes sets of optical fibers including a drop fiber that is routed from the first set of sequential fiber positions to a drop location and also including indexing fibers that are routed in an indexed configuration between the first set of sequential fiber positions and the second set of sequential fiber positions.

Another aspect of the present disclosure relates to an indexing component including stub-cables (e.g., break-out cables) terminating at multi-fiber connectors. The stub-cables include sets of optical fibers having ends supported at a first set of sequential fiber positions defined by a combination of the multi-fiber connectors such that the sequential fiber positions are sequenced across the multi-fiber connectors. The indexing component also includes a main cable including the sets of optical fibers, and a fan-out for coupling the stub-cables to the main cable. The indexing component further includes separate multi-fiber connection interfaces defining a second set of sequential fiber positions defined by a combination of the multi-fiber connection interfaces such that the sequential fiber positions are sequenced across the multi-fiber connection interfaces. The sets of optical fibers include a drop fiber that is routed from the first set of sequential fiber positions to a drop location. The sets of optical fibers also include indexing fibers that are routed in an indexed configuration between the first set of sequential fiber positions and the second set of sequential fiber positions.

Another aspect of the present disclosure relates to an indexing component including first and second stub-cables (e.g., break-out cables) terminating respectively at first and second multi-fiber connectors. The first stub cable includes a first set of optical fibers having ends supported at first sequential fiber positions defined by the first multi-fiber fiber connector. The second stub cable includes a second set of optical fibers having ends supported at second sequential fiber positions defined by the second multi-fiber connector. The indexing component also includes a main cable including the first and second sets of optical fibers, and a fan-out for coupling the first and second stub-cables to the main cable. The indexing component further includes a first multi-fiber connection interface defining third sequential fiber positions, and a second multi-fiber connection interface defining fourth sequential fiber positions. The first set of optical fibers includes a drop fiber that is routed from the first multi-fiber connector to a drop location. The first set of optical fibers also includes indexing fibers that are routed in an indexed configuration between the first sequential fiber positions and the third sequential fiber positions. The second set of optical fibers includes first indexing fibers that are routed in an indexed configuration between the second sequential fiber positions and the fourth sequential fiber positions. In certain examples, the second set of optical fibers can also include a second indexing fiber that is routed in an indexed configuration from the second multi-fiber connector to the first multi-fiber connection interface.

Certain other aspects of the present disclosure relate to fan-out configurations that can be used in components for supporting indexing architectures as well as other components where separating or fanning-out optical fibers are desired.

In one example, a specialty cable is utilized to provide a fan-out location. The fiber optic cable can include a pre-defined tear-location for separating the cable into two separate sections that function as stub-cables (e.g., break-out cables). In certain examples, the pre-defined tear-location is defined at a central location of the cable. In certain examples, the pre-defined tear-location is defined by notches that provide a reduced cross-sectional area for facilitating separating the two segments apart from one another. In certain examples, each of the separate segments includes a passage for receiving a set of optical fibers and a passage for receiving a strength member such as a glass reinforced polymeric (GRP) rod. In certain examples, the cable has an elongate transverse cross-sectional profile that defines a major axis extending through the fiber passages and the strength members and a minor axis that extends through the notches. In certain examples, a reinforcing structure such as a clip, housing, bracket or retainer can be mounted on the cable to prevent the cable from separating beyond a predetermined location. In certain examples, a first fiber passage and a first strength member are positioned on one side of the pre-determined tear-location and a second fiber passage and a second strength member are positioned on an opposite of the pre-defined tear-location.

Another aspect of the present disclosure relates to a fan-out structure including a block, tube, or other component that is filled with epoxy to anchor stub-cables (e.g., break-out cables, furcation cables, etc.) to a main cable and to seal the ends of the cables. In certain examples, the fan-out block can have a first end defining two receptacles for receiving ends of the stub-cables and a second end defining a receptacle for receiving the main cable. The fan-out block can define a central open region (e.g., a cavity accessible through a side window) defined between the receptacles for receiving adhesive such as epoxy. Strength members of the stub-cables and main cable can extend into the open region or cavity. An enlarged window can be provided in communication with the cavity for filling the cavity with an epoxy and for facilitating routing optical fibers from the main cable to the stub-cables. In certain examples, the stub-cables are formed by furcation tubes that receive optical fibers from the main cable. In certain examples, the receptacles for receiving the cables have elongate transverse cross-sectional shapes or profiles that correspond to elongate transverse cross-sectional shapes or profiles of the cables. In certain examples, the transverse cross-sectional profiles include major axes and minor axes. In certain examples, major axes of the transverse cross-sectional profiles are aligned along reference planes that extend through the window of the central cavity. In certain examples, a heat shrink sleeve including a shape memory material surrounding an adhesive layer can be mounted over the fan-out block and over portions of the stub-cables and the main cable to provide cable strain relief and to improve aesthetics. In certain examples, the fan-out block is made of a transparent plastic material.

A further aspect of the present disclosure relates to a fan-out device including a fan-out body having a furcated end with at least two separate legs or extensions. Each of the legs or extensions defines a receptacle for receiving a stub-cable (e.g., a break-out cable or furcation cable). The fan-out body can also define passages or receivers for receiving strength members of the stub-cables. Adhesive such as epoxy can be used to secure the strength-members within the strength member receivers. Side ports can be provided for injecting epoxy into the strength member receivers. The separate legs or extensions allow separate shape-memory elements (e.g., shrink-fit sleeves including internal adhesive) to be mounted over each of the legs and also over each of the corresponding stub-cables. Thus, the shape-memory sleeves can be used to seal each of the stub-cables. An opposite end of the fan-out structure can include a receptacle for receiving a main cable. Strength member receptacles can be provided for receiving strength members of the main cable. Adhesive injection ports can be provided in fluid communication with the strength member receptacles. One or more passages can be provided within the fan-out structure for routing sets of optical fibers from the main cable to the stub-cables. It will be appreciated that the stub-cables can be formed by furcation tubes/furcation cables. In practice, an end portion of a jacket of the main cable can be stripped away thereby exposing lengths of sets of optical fibers. The exposed lengths of optical fibers can be routed through the fan-out and into the furcation tubes/cables. Thereafter, the ends of the furcation tubes can be connectorized to form the stub-cable assemblies. In certain examples, a third heat shrink can be used to seal and provide strength relief between the main cable and the end of the fan-out structure. In certain examples, the fan-out structure can be made of a transparent material or other type of material that allows the passage of UV-light for curing adhesive therein. In certain examples, a cover or outer housing can be used to cover the fan-out structure and also cover at least portions of the heat shrink sleeves.

Still another aspect of the present disclosure relates to a fan-out arrangement including a fan-out housing having a first end and an opposite second end. Stub-cables (i.e., break-out cables or furcation cables) are routed through the first end. The stub-cables can be sealed by an elastomeric gasket arrangement loaded within the housing. A main cable can be routed into the fan-out housing through the second end. An elastomeric gasket can be used to seal the second end of the housing. An anchor member can be secured within the housing. The anchor member can include strength member receptacles for receiving strength members corresponding to the stub-cables and the main-cable. The anchor member can also include a passage for allowing a first set of optical fibers from the main cable to be routed to one of the stub-cables and a second set of optical fibers from the main cable to be routed to the other of the stub-cables. In certain examples, the gaskets can include a plurality of deformable ribs. In certain examples, the gaskets can also include tapered portions that are compressed about the cables by compression fittings, plugs or inserts that fit within the ends of the fan-out housing.

A variety of additional aspects will be set forth in the description that follows. These aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad concepts upon which the examples disclosed herein are based.

DETAILED DESCRIPTION

Aspects of the present disclosure relate to components for supporting indexing architectures. In certain examples, the components can include fan-out structures. In certain examples, the indexing architectures can include forward and reverse indexing. It will be appreciated that examples of forward and reverse indexing architectures and of systems where multiple indexing components are daisy-chained together are disclosed by PCT Int'l Publication No. WO 2014/190281 which is hereby incorporated by reference in its entirety.

FIG. 1illustrates an indexing component20in accordance with the principles of the present disclosure. The indexing component20includes two stub-cables22a,22bterminating at multi-fiber connectors24a,24b. The multi-fiber connectors24a,24bcan include multi-fiber ferrules. The stub-cables22a,22brespectively include sets of optical fibers26a,26bhaving ends supported at a first set of sequential fiber positions (e.g., positions 1-24) defined by a combination of the multi-fiber connectors24a,24b. For example, the multi-fiber ferrule of the multi-fiber connector24adefines positions 1-12 of the first set of sequential fiber positions28. Also, the multi-fiber ferrule of the multi-fiber connector24bdefines positions 13-24 of the first set of sequential fiber positions28. The indexing component20also includes a main cable30including the sets of optical fibers26a,26b. The indexing component20further includes a fan-out structure32for coupling the stub-cables22a,22bto the main cable30. The indexing component20further includes separate multi-fiber connection interfaces34a,34beach including separate multi-fiber ferrules. The multi-fiber connection interfaces34a,34bdefine a second set of sequential fiber positions36defined by the combination of the multi-fiber connection interfaces34a,34bsuch that the sequential fiber positions are sequenced across the multi-fiber connection interfaces34a,34b. For example, positions 1-12 of the second set of sequential fiber positions36are defined by the multi-fiber connection interface34a, while positions 13-24 of the second set of sequential fiber positions36are defined by the multi-fiber connection interface34b.

Referring still toFIG. 1, the sets of optical fibers26a,26binclude a drop fiber38that is routed from the first set of sequential fiber positions28(e.g., position 1) to a drop location40. The sets of optical fibers26a,26balso can include indexing fibers42that are routed in an indexed configuration between the first set of sequential fiber positions28and the second set of sequential fiber positions36. It is noted that indexing fiber42ais indexed from position 13 of the multi-fiber connector24bto position 12 of the multi-fiber connection interface34a. Indexing fibers43are routed from positions 14-24 of the multi-fiber connector24bare to positions 13-23 of the multi-fiber connection interface34b. Indexing fibers42are routed from positions 2-12 of the multi-fiber connector24ato positions 1-11 of the multi-fiber connection interface34a.

In certain examples, the multi-fiber connectors24a,24bcan include ruggedized fiber optic connectors. A ruggedized fiber optic connector is typically environmentally sealed and includes a robust fastening element for coupling to a corresponding connector or fiber optic adapter. Example fastening components can include twist-to-lock fasteners such as threaded sleeves, threaded nuts or bayonet-style fasteners.

In certain examples, the multi-fiber connection interfaces34a,34bcan be provided on a housing or terminal44. For example, the multi-fiber connection interfaces34a,34bcan be incorporated within ruggedized ports or adapter ports defined by the terminal44. Additionally, the drop location40can also include a ruggedized port for coupling to a ruggedized connector of a drop line or other device. It is noted that the indexing component20also includes drop fiber46routed from position 24 of the second set of sequential fiber positions36to drop location48. Drop location48can also include a ruggedized port. In other examples, multiple fibers can be routed to each drop location and the drop locations can include multi-fiber connection interfaces or a plurality of single fiber drop interfaces.

FIG. 2shows two of the indexing components20coupled together. It will be appreciated that inFIG. 2, only six fibers are shown for each of the multi-fiber connectors24a,24band for each of the multi-fiber connection interfaces34a,34b. This has been done for clarity to prevent the lines from bleeding together.

FIG. 3shows another indexing component20ahaving the same basic configuration as the indexing component20except two forward drop locations40have been provided and two reverse locations48have been provided. Also, the indexing fibers have been indexed two positions from the first set of sequential fiber positions28to the second set of sequential fiber positions36. Thus, ten optical fibers have been indexed from the multi-fiber connector24ato the multi-fiber connector interface34a, two optical fibers have been indexed from the multi-fiber connector24bto the multi-fiber connection interface34a, and ten optical fibers have been indexed from the multi-fiber connector24bto the multi-fiber connection interface34b.

FIG. 4shows an indexing component20bhaving the same configuration as the indexing component20except the multi-fiber connectors24a,24bhave been axially staggered relative to one another. Specifically, the stub-cables22a,22bhave been provided with different lengths. By staggering the multi-fiber connectors24a,24b, the multi-fiber connectors24a,24bhave a reduced cross-sectional profile which is helpful when passing such multi-fiber connectors24a,24bthrough a conduit.

FIG. 5illustrates an indexing component20cthat has the same general configuration as the indexing component20except the terminal44has been replaced with a fan-out configuration. In this configuration, a fan-out structure50has been provided. The multi-fiber connection interfaces34a,34bhave been provided by multi-fiber connectors mounted at the end of stub-cables52a,52band drop locations40,48have been shown as single-fiber fiber optic connectors mounted on the end of stub-cables54a,54b.

FIG. 6shows still another indexing component120in accordance with the principles of the present disclosure. In this example, rather than spreading a sequence of fiber positions across multiple multi-fiber connection interfaces, each multi-fiber connection interface has a separate fiber position sequence for indexing purposes. Thus, indexing does not occur across multiple multi-fiber connection interfaces.

Referring toFIG. 6, the indexing component120includes a first stub-cable122aterminating at a first multi-fiber connector124a. The first stub-cable122aincludes a first set of optical fibers126ahaving ends supported at first sequential fiber positions128adefined by the first multi-fiber connector124a. The indexing component120also includes a second stub-cable122bterminating at a second multi-fiber connector124b. The second stub-cable122bincludes a second set of optical fibers126bhaving ends supported at second sequential fiber positions128bdefined by the second multi-fiber connector124b. The indexing component also includes a main cable130including the first and second sets of optical fibers126a,126b. The indexing component120further includes a fan-out structure132for coupling the first and second stub-cables122a,122bto the main cable130. The indexing component120further includes a first multi-fiber connection interface134adefining third sequential fiber positions136aand a second multi-fiber connection interface134bdefining fourth sequential fiber positions136b. The first set of optical fibers126aincludes a drop fiber138athat is routed from the first multi-fiber connector124ato a drop location140a. The first set of optical fibers126aincludes indexing fibers142athat are routed in an indexed configuration between the first sequential fiber positions128aand the third sequential fiber positions136a. The second set of optical fibers126bincludes indexing fibers142bthat are routed in an indexed configuration between the second sequential fiber positions128band the fourth sequential fiber positions136b. The second set of optical fibers126bcan also include a drop fiber138bthat is routed from the second multi-fiber connector124bto a drop location140b.

It will be appreciated that a variety of fan-out configurations can be used to breakout the stub-cables from the main cable. A variety of fan-out structures, devices, blocks and arrangements suitable for use with the architectures ofFIGS. 1-6are set forth atFIGS. 7-25. The fan-out structures ofFIGS. 7-25can also be used for fan-out applications other than indexing architectures.

FIGS. 7 and 8depict a cable200in accordance with the principles of the present disclosure. The cable200is adapted for providing an integrated fan-out location and includes a cable jacket202including a first section204and a second section206with a predefined tear location208defined between the first and second sections204,206. Each of the first and second sections204,206defines a fiber passage210for receiving at least one optical fiber and a strength member passage212in which a strength member214is positioned. In one example, the predefined tear location208is defined by exterior notches216in the jacket. In one example, a plurality of optical fibers (e.g., a set of 12 optical fibers) is provided in each fiber passage210and the strength members214include glass reinforced polymeric rods.

In one example, the jacket202has an elongate transverse cross-sectional profile having a major axis M1and a minor axis M2. In this example, wherein the predefined tear location208is positioned along the minor axis M2, and the fiber passages210as well as the strength member passages212are aligned along the major axis M1.

FIGS. 9-12depict a fan-out structure230in accordance with the principles of the present disclosure. The fan-out structure230includes a fan-out block232that extends along an axis234. The fan-out block232has a first axial end236and an opposite second axial end238. The fan-out block232defines a central epoxy (i.e., adhesive) cavity240accessible through an enlarged side window242. The side window has at least one dimension that extends a across at least a majority of a width of the fan-out block232. The first axial end236defines two first axial cable receptacles244in fluid communication with the central epoxy cavity240. The second axial end238defines a single second axial cable receptacle246in fluid communication with the central epoxy cavity240. The enlarged window facilitates routing optical fibers from the main cable through the cable receptacles244for subsequent routing through the stub cables. In one example, a group of 12 fibers is routed through the fan-out to each of the cable receptacles244.

In one example, first cable receptacles244and the second cable receptacle246each have elongated transverse cross-sectional shapes sized to match a corresponding transverse cross-sectional profile of a cable jacket of a cable desired to be inserted therein. Strength members of the cables corresponding to the first and second cable receptacles244,246are all secured within the same central epoxy cavity240. Optical fibers from main cable secured at the second cable receptacle246are routed through the central epoxy cavity240to stub cables secured at the first axial cable receptacles244. The fan-out block232can be constructed of a plastic material through which ultraviolet light can pass. A single heat shrink sleeve can be positioned over the fan-out block, the stub cables and the main cable to provide cable strain relief and to enhance the aesthetic appearance of the fan-out.

As shown atFIG. 11, transverse cross-sectional shapes of the first axial cable receptacles244define major and minor axes M1, M2, and the side window242is positioned to be intersected by a reference plane R1that bisects the first axial cable receptacles along their minor axes M2.FIGS. 13-15show an alternative fan-out block232awhere the window242has been rotated 90 degrees about the axis234as compared to the example ofFIGS. 9-12. In the example ofFIGS. 13-15, the side window242is positioned to be intersected by reference planes R1that bisect the first axial cable receptacles along their major axes M1.

FIG. 16shows a fan-out structure including a fan-out body260having toothed pockets262at one end for receiving jacketed ends of stub cables and a toothed pocket264at an opposite end for receiving a jacketed end of a main cable. Strength member receptacles266are provided for individually receiving strength members (e.g., GRP rods) of the main cable and the stub cables.

FIGS. 19-21shows a fan-out assembly270in accordance with the principles of the present disclosure. The fan out assembly270includes a fan-out block272that extends along an axis274. The fan-out block272has a first axial end276and an opposite second axial end278. The first axial end276has a furcated configuration with first and second legs280,282. Each of the first and second legs280,282defines a break-out cable receptacle284in which a break-out cable286is secured. The second axial end278defines a main cable receptacle288in which a main cable290is secured. The fan-out assembly270also includes separate heat shrink sleeves292,294secured over each of the legs280,282and their corresponding break-out cables286and also includes a separate heat shrink sleeve296positioned over the second axial end278of the fan-out block272and the main cable290. In one example, strength members299of the break-out cables286and the main cable290are secured by adhesive within a common internal chamber298(seeFIGS. 21 and 17) within the fan-out block. In another example, strength members of the break-out cables and the main cable are secured by adhesive within separate strength member receptacles300(see fan-out block272aofFIG. 18). In certain examples, the strength members include glass reinforced rods. In certain examples, the fan-out block includes separate epoxy injection ports302for each of the strength member receptacles300. In certain examples, the fan-out block272is constructed of a plastic material through which ultraviolet light can pass. In certain examples, an outer housing304(half shown atFIG. 20) that blocks the passage of UV radiation and covers the fan-out block272as well as at least parts of each of the heat shrink sleeves.FIG. 17shows a fan-out block272bhaving furcation legs that are contoured to have opposing flat sides and convex portions that curve between the rounded sides.

FIGS. 22-25show a fan-out assembly310in accordance with the principles of the present disclosure. The fan-out assembly310includes a fan-out housing312that extends along an axis314. The fan-out housing312includes a first axial end316defined by a first housing piece318and a second axial end320defined by a second housing piece322. The first axial end316defines an elongate receptacle324and the second axial end320defines a main cable receptacle326. A first sealing arrangement328mounts within the elongate receptacle324at the first axial end of the fan-out housing312for sealing break-out cables routed into the fan-out housing312. The first sealing arrangement328also includes an elastomeric gasket arrangement330for receiving the breakout cables. The elastomeric gasket arrangement330includes first annual ribs332for sealing against the break-out cables and second annular ribs334for sealing against an interior of the fan-out housing312. The first sealing arrangement328also includes an insert336that fits within the first end316of the fan-out housing312and compresses the elastomeric gasket arrangement330. The insert336and the gasket arrangement330meet at a nested, tapered interface338. A second sealing arrangement340mounts within the second axial end320of the fan-out housing312for sealing a main cable routed into the fan-out housing312through the main cable receptacle326. The second sealing arrangement includes an elastomeric gasket342for receiving the main cable. The elastomeric gasket342including first annular ribs344for sealing against the main cable and second annular ribs346for sealing against an interior of the fan-out housing312. The second sealing arrangement340also includes an insert348that fits within the second end320of the fan-out housing312and compresses the elastomeric gasket342. The insert348and the gasket342meet at a nested, tapered interface350. A cable anchoring block352is mounted within the fan-out housing312. The cable anchoring block352includes an elongate central opening354through which optical fibers from the main cable are routed to reach the break-out cables. The cable anchoring block352further includes cable strength member receptacles356positioned on opposite sides of the elongate central opening354for receiving strength rods of the break-out cables and strength rods of the main cable. The strength rods can be adhesively affixed in the cable strength member receptacles356. In one example, an o-ring seal or other seal can be compressed between the first and second housing pieces to seal the interface between the two housing pieces.

Various modifications and alterations of this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure, and it should be understood that the scope of this disclosure is not to be unduly limited to the illustrated examples set forth herein.