Multi-port optical connection terminal assemblies supporting optical signal splitting, and related terminals and methods

Multi-port optical connection terminal assemblies, related terminals and methods are disclosed herein. In one embodiment, a multi-port optical connection terminal assembly may include an enclosure including an internal cavity, an input orifice, and optical connection nodes. The multi-port optical connection terminal assembly may also include an optical splitter comprising a body, an input optical fiber, and output optical fibers. At least a portion of the body of the optical splitter may be disposed outside the internal cavity of the enclosure. The input optical fiber of the optical splitter may be disposed outside the internal cavity of the enclosure, and the plurality of the output optical fibers of the optical splitter may be disposed inside the internal cavity. In this manner, the enclosure of the multi-port optical connection terminal assembly is not required to be sized to completely contain the optical splitter.

BACKGROUND

1. Field of the Disclosure

The technology of the disclosure relates to multi-port optical connection terminals and assemblies which may be used to distribute optical signals from optical fibers.

2. Technical Background

Benefits of optical fiber use include extremely wide bandwidth and low noise operation. Because of these advantages, optical fiber is increasingly being used for a variety of applications, including but not limited to broadband voice, video, and data transmission. As a result, fiber optic communications networks include a number of interconnection points at which multiple optical fibers are interconnected. Fiber optic communications networks also include a number of connection terminals, examples of which include, but are not limited to, network access point (NAP) enclosures, aerial closures, below grade closures, pedestals, optical network terminals (ONTs), and network interface devices (NIDs). In certain instances, the connection terminals include connector ports or nodes, typically opening through an external wall of the connection terminal. The connection terminals are used to establish optical connections between optical fibers terminated from the distribution cable and respective optical fibers of one or more drop cables, extended distribution cables, tether cables or branch cables, collectively referred to herein as “drop cables,” unless specified otherwise. The connection terminals are used to readily extend fiber optic communications services to a subscriber. In this regard, fiber optic networks are being developed that deliver “fiber-to-the-curb”(FTTC), “fiber-to-the-business” (FTTB), “fiber-to-the-home” (FTTH) and “fiber-to-the-premises” (FTTP), referred to generically as “FTTx.”

In conventional FTTx deployments depicted inFIG. 1, a fiber optic network10is provided. The fiber optic network10typically delivers service to subscribers12through optical fiber distribution cables14and subscriber cables16. For example, the fiber optic network10may begin at a trunk cable18originating from a central office20leading to a splitter/splice cabinet22in the field where a distribution cable14is connected. The distribution cable14may then be routed aerially or below ground through the residential neighborhood served by the fiber optic network10. The subscriber cables16servicing individual subscribers12may be connected with the distribution cable14through terminations at mid-span access points24, branch cables26, connector ports28of multi-port splitter boxes30, and cables32.

FIGS. 2A to 2Bdepict a conventional multi-port splitter box30including a base34, cover36, and eight (8) connector ports28. Although eight (8) connector ports28are shown inFIGS. 2A and 2B, multi-port splitter box30may have any number of connector ports28. An optical management shelf38is installed into the multi-port splitter box30that includes an optical splitter40and a splice protector42attached to its top surface44. An optical fiber46of a cable32enters an entry orifice48of the multi-port splitter box30and wraps around containment surfaces50around an orifice52in the top surface44of the optical management shelf38. The optical fiber46may be spliced to an input optical fiber54in the splice protector42. The input optical fiber54is attached to the optical splitter40which may have output optical fibers56. The output optical fibers56include connectors58attached to their distal ends which may be subsequently attached to the connector ports28of the multi-port splitter box30.

In general, the performance of input optical fiber54, the output optical fibers56, and the optical splitter40can be affected by mechanical and environmental issues surrounding the output splitter box30. Mechanical issues may include small-radius bends and cyclical and episodic movements of the optical fibers. For example, standard single-mode fiber may experience high optical attenuation at small-radius bends. Environmental issues may be water when the output splitter box30is installed underground. Thus, the conventional approach has been to locate the input optical fiber54, output optical fibers56, and the optical splitter40inside of the output splitter box30. This conventional approach has resulted in the multi-port splitter box30becoming too large in many cases for installation in the field. Ideally, the multi-port splitter box30should be sufficiently small in size to be able to pass through ducts and small passageways underground during installation to service subscribers12, as an example.

SUMMARY OF THE DETAILED DESCRIPTION

Embodiments disclosed in the detailed description include multi-port optical connection terminal assemblies, related terminals and methods. In one embodiment, a multi-port optical connection terminal assembly is disclosed. This multi-port optical connection terminal assembly may include an enclosure including an internal cavity, an input orifice, and a plurality of optical connection nodes. The multi-port optical connection terminal assembly may also include an optical splitter comprising a body, an input optical fiber, and plurality of output optical fibers. At least a portion of the body of the optical splitter may be disposed outside the internal cavity of the enclosure. The input optical fiber of the optical splitter may be disposed outside the internal cavity of the enclosure, and the plurality of the output optical fibers of the optical splitter may be disposed inside the internal cavity. In this manner, the enclosure of the multi-port optical connection terminal assembly is not required to be sized to completely contain the optical splitter. In this regard as a non-limiting example, the enclosure of the multi-port optical connection terminal may be provided of a smaller size enabling easier installation through narrow passageways and ducts because of the smaller enclosure size.

In another embodiment, a multi-port optical connection terminal assembly is provided. The multi-port optical connection terminal assembly may comprise an enclosure, an optical splitter, and a splice point. The enclosure may comprise an internal cavity, an input orifice, and a plurality of optical connection nodes. The optical splitter may comprise a body, an input optical fiber extending from the body, and plurality of output optical fibers extending from the body. The splice point may be located on the input optical fiber and configured to contact an optical fiber of a cable. A portion of the body of the optical splitter may be disposed between the splice point and the enclosure. The plurality of the output optical fibers may be disposed inside the internal cavity, and the input optical fiber may be located outside the internal cavity. In this manner, the multi-port optical connection terminal assembly may, for example, have a smaller size enabling it to be installed through narrow passageways and ducts because of the smaller enclosure.

In another embodiment, a method of assembling a multi-port optical connection terminal assembly is disclosed. This method may be comprised of providing an optical splitter comprising a body, an input optical fiber, and a plurality of output optical fibers. This method may also comprise providing an enclosure comprising an internal cavity, an input orifice, and a plurality of optical connection nodes. In a later step of the method, a furcation structure may be created. Next, the method may also comprise a step to attach the furcation structure to the enclosure. Finally, the enclosure may be sealed with a cover of the enclosure. At least a portion of the body of the optical splitter may be disposed outside the internal cavity of the enclosure. The input optical fiber may be disposed outside the internal cavity of the enclosure, and the plurality of output optical fibers may be disposed inside the internal cavity. In this manner, the method of assembling the multi-port optical connection terminal assembly may, for example, be less expensive to manufacture because of the smaller enclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all embodiments are shown. Indeed, the concepts may be embodied in many different forms and should not be construed as limiting herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

Embodiments disclosed in the detailed description include multi-port optical connection terminal assemblies, related terminals and methods. In one embodiment, a multi-port optical connection terminal assembly is disclosed. This multi-port optical connection terminal assembly may include an enclosure including an internal cavity, an input orifice, and a plurality of optical connection nodes. The multi-port optical connection terminal assembly may also include an optical splitter comprising a body, an input optical fiber, and plurality of output optical fibers. At least a portion of the body of the optical splitter may be disposed outside the internal cavity of the enclosure. The input optical fiber of the optical splitter may be disposed outside the internal cavity of the enclosure, and the plurality of the output optical fibers of the optical splitter may be disposed inside the internal cavity. In this manner, the enclosure of the multi-port optical connection terminal assembly is not required to be sized to completely contain the optical splitter. In this regard as a non-limiting example, the enclosure of the multi-port optical connection terminal may be provided of a smaller size enabling easier installation through narrow passageways and ducts because of the smaller enclosure size.

In this regard,FIGS. 3A and 3Billustrate a schematic diagram and an exploded view, respectively, of one embodiment of a multi-port optical connection terminal assembly60. It may be configured to split an optical signal carried by an optical fiber62in a cable64and deliver a plurality of split optical signals downstream at each of a plurality of optical connection nodes66. As non-limiting examples, the cable64may be a branch cable, distribution cable, a stub cable, tether cable, or any other type of cable. The cable64may be unconnectorized as provided inFIGS. 3A and 3Bor connectorized in other embodiments. InFIG. 3Athe main external components of the multi-port optical connection terminal assembly60in this embodiment are depicted. In this embodiment, the multi-port optical connection terminal assembly60includes an enclosure68which comprises a base69and a cover70. The cover70operates as part of the enclosure68to seal an internal cavity78of the enclosure68from the environment outside. Sealing the internal cavity78may be important because the multi-port optical connection terminal assembly60may be, for example, underground or suspended from a utility pole.

A furcation structure72may be attached to a portion74of the enclosure68by a second protective tube76. This enables at least a portion of a body of an optical splitter (introduced below as element94) within the furcation structure72to be located at least partially outside of the enclosure68. The furcation structure72may be used to reduce the size of the enclosure68and to protect the body of the optical splitter outside of the enclosure68.

A protective jacket80extends from the furcation structure72towards the cable64. A splice protector82may be disposed between the cable64and the protective jacket80to optically couple an optical fiber (introduced below) in the protective jacket80to the optical fiber62of the cable64. The splice protector82may also serve to environmentally protect optical fibers within by forming a tight contact seal with the protective jacket80and a cable jacket86of the cable64.

The plurality of optical connection nodes66may be attached to a plurality of angled exterior surfaces88of the enclosure68to allow for optimal orientation of downstream cables and their associated connectors (not shown) to carry the split optical signals downstream from the multi-port optical connection terminal assembly60to subscribers.

FIG. 3Bprovides more detail as to the components of the multi-port optical connection terminal assembly60. The enclosure68may comprise the base69and the cover70. The base69and the cover70may be formed as thin-walled components made of a strong generally liquid-impermeable material, for example, such as plastic or metal. The base69and the cover70may be manufactured, for example, using stamping or injection molding techniques as non-limiting examples.

The plurality of optical connection nodes66may seal a plurality of output orifices90of the enclosure68. The plurality of output orifices90may be disposed in the plurality of angled exterior surfaces88as shown inFIG. 3B. The plurality of optical connection nodes66may be connected to the plurality of output orifices90through, for example, a threaded connection.

The internal cavity78may be formed by a volume enclosed by the base69and cover70and accessible when the cover70is attached by fasteners, as a non-limiting example, screws140, or welded, for example by an induction process. Although the plurality of output orifices90and the input orifice138are depicted inFIGS. 3A to 3Bas being within the base69of the enclosure68, some or all of the plurality of output orifices90and the input orifice138may also be included as part of the cover70. It is noted that the cover70may be a non-limiting embodiment of the multi-port optical connection terminal assembly60. Other embodiments of the enclosure68may be one-piece, or have the cover70permanently attached or otherwise secured to the base69.

With continuing reference toFIG. 3B, the multi-port optical connection terminal assembly60may utilize an optical splitter92to split optical signals from the optical fiber62of the cable64. The purpose of the optical splitter92may be to transmit at least a portion of the optical signal to or from the cable64to or from the plurality of optical connection nodes66. The optical splitter92may include a body94where the optical signals are split. Each optical fiber may contain many independent channels of information, each having a different wavelength of light. The body94of the optical splitter92may be compatible with either single-mode fiber optical cables or multi-mode optical cables. The body94of the optical splitter92may have components to support wave-division multiplexing (WDM), code division multiplexing (CDM), course wave division multiplexing (CWDM), and/or dense wave division multiplexing (DWDM), or other means of managing and/or transmitting optical signals. Many of these data handling approaches may allow for multiple signals to be efficiently transported on a single carrier wave by the optical fiber62in the cable64before being split by the optical splitter92into their component signal parts to be available for downstream optical fibers (not shown) connected at the plurality of optical connection nodes66. In these approaches, the optical signal available at each of the optical connection nodes66may be at least a portion of the multiple signals carried by the optical fiber62of the cable64.

Continuing the discussion of the optical splitter92, the body94may include an optical de-multiplexer comprising thin film filter (TFF) technology; a fiber bragg grating (FBG) with optical circulators; and/or arrayed waveguide gratings (AWG). The body94of the optical splitter92may have a rectangular cross-section as shown inFIG. 3B. Alternatively, other cross section shapes may be utilized, such as an oval-type, or polygon-type.

The optical splitter92may also include one or more input optical fibers96and a plurality of output optical fibers98connected directly to the body94of the optical splitter92. The input optical fiber96may be a single-mode or multi-mode optical fiber extending from an input end100of the body94of the optical splitter92. A splice point102may be disposed on the input optical fiber96, where the input optical fiber96may be optically coupled to the optical fiber62of the cable64. The optical coupling (also known as splicing) may be accomplished mechanically or by fusing the optical fibers62,96together. Note that the terms “input” output fiber and “output” optical fiber are not limited to and do not imply a limitation of a direction of optical signals. The optical splitter92may be configured such that optical signals can flow uni-directional in either direction, or bi-directionally between the input optical fiber96and the output optical fibers98. All possibilities are contemplated by the optical splitter92and the optical splitters disclosed herein.

The input optical fiber96of the optical splitter92may include a protective jacket between the splice point102and the body of the optical splitter92for additional environmental and mechanical protection. In this regard, the protective jacket80may be disposed between the input optical fiber96and the body94of the optical splitter92to help provide additional protection. The protective jacket80may be oval, round, or any other geometry in cross-section with an orifice through the axis by which may be disposed a portion103of the input optical fiber96. The protective jacket80may abut the input end100of the body94of the optical splitter92to provide protection adjacent to the body94. Mechanical protection of the input optical fiber96may be particularly important next to the body94, because the body94may be rigid and accordingly, bending forces transmitted from the cable64may cause a sharp bend in the input optical fiber96that may cause optical attenuation or damage. For example, traditional optical fibers could suffer optical attenuation for certain bend radii.

The optical fiber62of the cable64may include the cable jacket86, as previously discussed, to protect the optical fiber62from environmental issues. The cable jacket86may be partially stripped from a terminating end104of the cable64to expose the optical fiber62that may be subsequently spliced to the input optical fiber96. Accordingly, a splice protector82may be utilized to protect the splice point102and the terminating end104of the cable64. The splice protector82may be comprised of one or more components82(1),82(2) or may be formed as a single overmolded component surrounding the splice point102and the terminating end104. The advantage of being a single overmolded component may be that a tight seal may be formed around the splice point102.

The plurality of output optical fibers98extend from the body94of the optical splitter92at an output end106of the body94. Individual ones of the plurality of output optical fibers98may be inside a respective protective jacket in the form of a buffer tube83, as a non-limiting example, a 900 μm buffer tube, also referred to as a “loose tube.” In other words, a separate protective jacket83may be disposed around an individual output optical fiber98. The protective jacket83on an output optical fiber98may extend over or disposed around a portion117of the output fiber98. However, the protective jacket83may not contact the splitter body94, but may need to be a short distance away from the splitter body94to avoid optical signal attenuation. The protective jacket on the output optical fiber protects the optical fibers from abrasion when the multiport is being handled and aids in the connectorization of the output fibers.

The plurality of output optical fibers98deliver the output signals of the optical splitter92to the plurality of optical connection nodes66, and may be comprised of single-mode or multi-mode optical fibers. In a non-limiting example, the plurality of output optical fibers98may be in the form of a fiber optic ribbon cable wherein each of the plurality of output optical fibers98may exit the body94of the optical splitter92in an array of optical fibers “m” (m) fibers high and “n” (n) fibers across, or in other words (“m×n”). Typical non-limiting values for “m” and “n” may be positive integers 1, 2, 3. Other output configurations and quantities of the plurality of output optical fibers98may also occur. The plurality of output optical fibers98may also include a protective cable jacket (not shown) to protect the plurality of output optical fibers98between the body94and the plurality of optical connection nodes66. Each of the plurality of output optical fibers98may also comprise a plurality of optical fiber connectors108to connect the plurality of output optical fibers98to the plurality of optical connection nodes66. The advantage of having optical fiber connectors108may be that the plurality of output optical fibers98may have the optical fiber connectors108attached in a facility enabling easier utilization in the field.

An output strain relief device107may be attached to the output end106of the body94. The output strain relief device107may be utilized to protect the plurality of output optical fibers98from being bent more than the minimum bend radius of the plurality of output optical fibers98that may be allowed before damage or unacceptable optical attenuation occurs.

As to the topic of attaching components of the multi-port optical connection terminal assembly60, a protective tube110may be used to attach the protective jacket80to the body94of the optical splitter92. The protective tube110may be in a cylindrical form and comprise an orifice surface112, which may be concentric around a longitudinal axis A1of the protective tube110. A portion114of the protective jacket80and a portion116of the body94of the optical splitter92may form the attachment with the orifice surface112of the protective tube110. A tight attachment between the protective tube110and the portions114,116may be optionally enhanced by an inclusion of an adhesive lining118upon the orifice surface112of the protective tube110. The adhesive lining118may comprise epoxy or another adhesive compatible with plastic, rubber, or metal, such as aluminum for example.

Moreover, the protective tube110may be sensitive to heat wherein, upon heating above a specified temperature, a material of the protective tube110may constrict, causing the protective tube110to tighten around the portions114,116and thereby increase a frictional and/or chemical attachment strength between the orifice surface112and the portions114,116. The protective tube110may be made from a strong tear-resistant material such as metal or plastic. The protective tube110may be a heat shrink tube.

Also, a furcation tube120in combination with a potting compound122(discussed below in regard toFIG. 9) may provide further strength and rigidity to the attachment between the protective tube110and the portions114,116. A portion123of the furcation tube120may be attached to the enclosure68through the second protective tube76. The furcation tube120in this embodiment comprises a second orifice surface124which may be concentric around a longitudinal axis A1of the furcation tube120. The furcation tube120may surround at least a portion of the protective tube110, as well as the portions114,116. The potting compound122may be disposed between the furcation tube120, specifically the second orifice surface124, and the protective tube110. The furcation tube120may be made of metal or plastic, for example, that may be strong and tear-resistant. The potting compound122may be comprised of epoxy or a different potting compound compatible with metal and/or plastic.

In order to simplify the subsequent discussion, the furcation structure72describes the strengthened attachment between the body94of the optical splitter92, the protective jacket80, and the associated components required to attach this strengthened attachment to the enclosure68. The furcation structure72may be comprised of the furcation tube120, the potting compound122, the protective tube110, the portion114of the protective jacket80and the portion116of the body94of the optical splitter92.

Next, the furcation tube120of the furcation structure72may be attached to the enclosure68. The second protective tube76may be utilized to attach the furcation tube120to the portion74of the enclosure68. The portion74of the enclosure68may be an outer surface of a neck portion protruding as part of the enclosure68, and thereby provide a convenient surface for attachment as shown inFIG. 3B.

Moreover, the second protective tube76may be in cylindrical form and comprise a third orifice surface128which may be concentric around a longitudinal axis A1of the second protective tube76. The portion123of the furcation tube120and the portion74of the enclosure68come into contact with the third orifice surface128to form an attachment. A tight attachment between the third orifice surface128of the second protective tube76and the portion123of the furcation tube120and the portion74of the enclosure68may be enhanced by an inclusion of a second adhesive lining130along the third orifice surface128of the second protective tube76. The second adhesive lining130may comprise epoxy or another adhesive compatible with plastic, rubber, or metal, such as aluminum for example. The material of the second protective tube76may be a strong tear-resistant material and may be different than the material of the protective tube110. Examples of suitable materials are metal or plastic.

The second protective tube76may be sensitive to heat, wherein upon heating above a specified temperature, the second protective tube76may constrict causing the second protective tube76to tighten around the portion123of the furcation tube120and the portion74of the enclosure68, and thereby increase the strength of the attachment between the third orifice surface128and the portion123of the furcation tube120and the portion74of the enclosure68. The second protective tube76may be a heat shrink tube.

The attachment between the furcation structure72and the enclosure68may be enhanced by a clamp132attached to the furcation structure72or a second portion136of the body94of the optical splitter92with a fastener134, as a non-limiting example. The clamp132may be located inside the internal cavity78of the enclosure68for protection against environmental and mechanical issues. The clamp132may be attached itself to the enclosure68, or alternatively may merely form an interference fit with the enclosure68to thereby prevent the furcation structure72from separating from the enclosure68.

The second portion136of the body94of the optical splitter92may or may not be located within the internal cavity78of the enclosure68. In embodiments where the optical splitter92is located within, the optical splitter92may enter the internal cavity78at the input orifice138of the enclosure68.

The cover70may be fastened to the base69with one or more fasteners140to make up the enclosure68. The cover70may include seals (not shown) to form a tight protective attachment with the enclosure68and thereby help better isolate the internal cavity78of the enclosure68from the outer environment. The seals may prevent contaminants such as liquid from entering the interior cavity78. Other methods for fastening may also be employed which do not employ fasteners, such as induction welding, sonic welding, and chemical bonding, as non-limiting examples.

FIG. 4depicts an exemplary method142of assembling a multi-port optical connection terminal assembly as depicted inFIGS. 3A to 3B. The first step of the method142may be comprised of providing the optical splitter92and the enclosure68(step144inFIG. 4). Next, the furcation structure72may be created (step146). In the next step the furcation structure72may be attached to the enclosure68(step148). Once these are completed, then the enclosure68may be sealed with the cover70of the enclosure68(step150). Lastly, the input optical fiber96may be optically coupled to an optical fiber62of the cable64at the splice point102disposed in the input optical fiber96(step152). Each of these steps will be discussed in more detail below with continuing reference toFIGS. 5A to 19.

In this regard,FIGS. 5A to 5Billustrate details of providing the optical splitter92and the enclosure68(step144inFIG. 4) in two sub-steps. A first sub-step154inFIG. 5Amay consist of providing the optical splitter92, which may comprise a body94, an input optical fiber96, and a plurality of output optical fibers98. A second sub-step156, depicted inFIG. 5B, may consist of providing the enclosure68comprising the base69, the cover70, the internal cavity78, the input orifice138, and the plurality of optical connection nodes66.

Next,FIG. 6illustrates a first sub-step158of creating the furcation structure (step146). The purpose of the furcation structure72may be to locate at least a portion of the body94of the optical splitter92outside of the enclosure68so that the multi-port optical connection terminal assembly60may be smaller in size while providing sufficient protection for the body94of the optical splitter92. In sub-step158, the protective jacket80may be disposed around at least the portion of the input optical fiber96and abutted against the input end100of the body94of the optical splitter92. The input optical fiber96may extend outside the body94of the optical splitter92from the input end100of the body94of the optical splitter92. In addition, as part of sub-step158, protective jackets may be placed around the output optical fibers98.

Continuing with step146inFIG. 4,FIG. 7illustrates a second sub-step160of creating the furcation structure72, wherein the protective tube110may be disposed around at least the portion114of the protective jacket80and the input end100of the body94of the optical splitter92. The protective tube110may be configured to attach the protective jacket80to the input end100of the body94of the optical splitter92.

In the case that the protective tube110is a heat shrink tube, then heat may be applied above a specified temperature to the protective tube110. The heat may tighten the protective tube110around the portion of the protective jacket114and the input end100of the body94of the optical splitter92. The tightening may increase the strength of the attachment between the portion of the protective jacket114and the input end100of the body94. The advantage of using a heat shrink tube may be that it may be installed quickly, with low cost, and has sufficient strength.

With regard to step146inFIG. 4,FIGS. 8 to 9illustrate a third sub-step162of creating the furcation structure. The purpose of this third sub-step may be to further protect the input optical fiber96and a portion of the body94of the optical splitter92by creating a larger rigid structure. In this sub-step162, the protective jackets80may be bound to the body94of the optical splitter92by disposing the furcation tube120around the at least the portion111of the protective tube110, the input end100of the body94of the optical splitter92, the output end107of the body94of the optical splitter92, and the at least the portion114of the protective jacket80around the input optical fiber and at least a portion117the protective jackets83around the output optical fibers98. Next, the potting compound122may be disposed inside the furcation tube120and around at least a portion111of the protective tube110. The potting compound122may be, for example, epoxy or another substance providing a high rigidity when cured.

With regard to step148inFIG. 4,FIG. 10illustrates a first sub-step164of attaching the furcation structure72to the enclosure68. The purpose of sub-step164may be to protect the output end106of the body94of the optical splitter92. In sub-step164, the output end106of the body94of the optical splitter92may be disposed within the internal cavity78of the enclosure68. The plurality of output optical fibers98may extend outside the body94of the optical splitter92from the output end106of the body94of the optical splitter92. Although embodiments of the multi-port optical connection terminal assembly60may seek to minimize the volume of the internal cavity of the enclosure68to save space, having the output end106of the optical splitter92disposed within the enclosure68has two advantages. First, the output end106is better protected within the internal cavity78of the enclosure68. The second is that the furcation structure72may be made shorter in the longitudinal direction. Thus, when the furcation structure72is rigidly connected to the enclosure68as a cantilever, there may be less risk of breakage from accidental impacts during handling or transportation.

In the second sub-step of step148inFIG. 4,FIGS. 11 to 12illustrate a second sub-step166of attaching the furcation structure72to the enclosure68. The purpose of sub-step166may be to both attach the body94of the optical splitter92to the enclosure68and to close the input orifice138of the enclosure68. In sub-step166, the second protective tube76may be disposed around at least the portion123of the furcation tube120and the portion74of the enclosure68to begin to form the attachment.FIG. 12depicts the second protective tube76securely attached to the portion123of the furcation tube120and the portion74of the enclosure68. This secure attachment may be the result of changing the shape of the second protective tube76by, for example, heating, or by providing a second protective tube76with an inner surface closely matching the outer surfaces of the furcation tube120and the portion74of the enclosure68. Further,FIG. 12depicts two separate descriptions of the location of the optical splitter. In the first, at least the portion116of the body94of the optical splitter92may be disposed outside the internal cavity78of the enclosure68and the plurality of output optical fibers98may be disposed inside the internal cavity78of the enclosure68. In the second, the portion116of the body94of the optical splitter92may be disposed between the splice point102and the enclosure68, and the input optical fiber96may be located outside the internal cavity78.

In the third sub-step of step148inFIG. 4,FIG. 13illustrates a third sub-step168of attaching the furcation structure72to the enclosure68. The purpose of sub-step168may be to further secure the attachment of the body94of the optical splitter92to the enclosure68. In sub-step168the portion123of the furcation tube120may be secured to the enclosure68with a clamp132. The clamp132may be tightened with the fastener134which may be, for example, comprised of a nut and bolt set, or wing nut assembly, as a non-limiting example.

In the last sub-step170of step148inFIG. 4, attaching the furcation structure72to the enclosure68may be shown by continued reference toFIG. 13. The purpose of sub-step170may be to optically and/or mechanically couple the plurality of the optical connection nodes66to the optical splitter92. The plurality of the optical connection nodes66may be comprised of the plurality of optical fiber connectors108and may be optically and/or mechanically connected to each of the plurality of output optical fibers98. As shown inFIG. 11and previously discussed, the plurality of optical fiber connectors108may be optically attached to the plurality of output optical fibers98prior to being attached to the plurality of optical connection nodes66. Any number of optical connection nodes66may be optically coupled downstream from the optical splitter92consistent with the method142as depicted inFIG. 14. The number of optical connection nodes66may be dependent on the number of subscribers serviced, cost, or other installation considerations.

In step150inFIG. 4,FIG. 13further illustrates sealing the enclosure68with the cover70of the enclosure68. The purpose of step150may be to seal the internal cavity78of the enclosure68from the outside. For example, the fasteners140may be used to seal the cover70to the base69. The multi-port optical connection terminal assembly60may be installed either within a sheltered building, underground in a wet trench, or suspended from a utility pole during inclement weather, so sealing the enclosure68may be critical. Other components (not shown) may be utilized for sealing the enclosure68, for example, rubber gaskets placed between the cover70and base69.

FIG. 13also shows that the plurality of output optical fibers98are connected to the plurality of the optical connection nodes66without the use of the optical management shelf38, as may be needed for some current designs. Accordingly, the present embodiment has a lower quantity of parts and thereby may be less expensive to manufacture.

Other non-limiting embodiments to the method142are now also disclosed. These embodiments may be beneficial by either further reducing the size of the internal cavity78or improving the attachment of the furcation structure72to the enclosure68. For example, one or more interface surfaces178may be made in the furcation structure72as depicted inFIG. 18. The one or more interface surfaces178may be created, for example, by a material removal process at a milling machine. The one or more interface surfaces178may be used advantageously to contact complementary surfaces in the portion74of the enclosure68to further improve attachment by preventing a twist of the furcation structure72relative to the enclosure68. Also, one or more interface surfaces178may serve as one or more contact surfaces (not shown) with the clamp132.

Another non-limiting embodiment to the method142comprises disposing the furcation tube120and potting compound122around the entire body94of the optical splitter92. This embodiment depicted inFIG. 19enables the furcation structure72to be attached to the enclosure68so that the body94of the optical splitter92may be disposed outside the internal cavity78. In this manner, the size of the internal cavity78may advantageously be made even smaller.

Next, in a first sub-step172of step152inFIG. 4,FIGS. 15 to 16illustrate optically coupling the input optical fiber96to the optical fiber62of the cable64at the splice point102disposed in the input optical fiber96. The purpose of first sub-step172may be to optically couple the optical fiber62of the cable64to the optical splitter92.FIG. 15depicts the splice point102disposed in the input optical fiber96and the cable64prior to optical coupling.FIG. 16illustrates the optical fiber62of the cable64optically coupled to the input optical fiber96at the splice point102. Optically coupling (or splicing) may involve either mechanical splicing or fusion splicing. Mechanical splicing may involve alignment devices (not shown) configured to hold the two fiber ends in a precisely aligned position to enable light to pass from one optical fiber to the other. Fusion splicing may involve splicing equipment (not shown) that precisely aligns the two ends of different optical fibers together and then energy may fuse or weld together these ends. The energy may be provided from an electric arc or other heat source.

Next, in a second sub-step174of step152inFIG. 4,FIG. 17illustrates the splice protector82disposed around the splice point102, a second portion176of the protective jacket80, and the cable jacket86of the cable64. The purpose of the second sub-step174may be to protect the splice point102, the input optical fiber96, and the optical fiber62of the cable64by keeping out contaminants and preventing harmful bending. At optical coupling locations the input optical fiber96and the optical fiber62of the cable64may be stripped of protective coatings and strength members and thereby may be generally be vulnerable to tensile and bending forces as well as contaminants without the splice protector82. For example, some unprotected optical fibers may only have a maximum safe tensile strength of 0.5 to 1.5 pounds as a non-limiting example. The splice protector82may comprise over-molded plastic, heat shrink tubing, silicone gel, and/or mechanical crimp protectors to keep the splice point102protected from outside elements and breakage. Alternative embodiments of the splice protector82may allow a second optical fiber (not shown) of the cable64to exit the splice protector82in parallel to the optical fiber62of the cable64and be available for optical coupling downstream.

As used herein, it is intended that terms “fiber optic cables” and/or “optical fibers” include all types of single mode and multi-mode light waveguides, including one or more optical fibers that may be up-coated, colored, buffered, ribbonized and/or have other organizing or protective structure in a cable such as one or more tubes, strength members, jackets or the like. The optical fibers disclosed herein can be single mode or multi-mode optical fibers. Likewise, other types of suitable optical fibers include bend-insensitive optical fibers, or any other expedient of a medium for transmitting light signals. An example of a bend-insensitive, or bend resistant, optical fiber is ClearCurve® Multimode fiber commercially available from Corning Incorporated. Suitable fibers of this type are disclosed, for example, in U.S. Patent Application Publication Nos. 2008/0166094 and 2009/0169163, the disclosures of which are incorporated herein by reference in their entireties. Many modifications and other embodiments not set forth herein will come to mind to one skilled in the art to which the embodiments pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. As non-limiting examples, the type of enclosure for the multi-port connector optical connect terminal assembly, number of ports, types of splices, types of splice protections, type of cable, and type and configuration of optical splitters can vary as desired.

Therefore, it is to be understood that the description and claims are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. It is intended that the embodiments cover the modifications and variations of the embodiments provided they come within the scope of the appended claims and their equivalents. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.