The present disclosure relates generally to a bare-fiber connection system that includes first and second multi-fiber fiber optic connectors mounted in a multi-fiber adapter. The multi-fiber fiber optic connectors are bare-fiber connectors that each include a connector body and a plurality of optical fibers extending through the connector body. The bare-fiber connection system includes a latching arrangement for securing the first and second multi-fiber fiber optic connectors respectively in first and second adapter ports. The first and second multi-fiber fiber optic connectors and the multi-fiber adapter lack integrated structures for releasing the first and second multi-fiber fiber optic connectors from the first and second adapter ports.

TECHNICAL FIELD

The present disclosure relates generally to multi-fiber connectivity. More particularly, the present disclosure relates to bare-fiber multi-fiber connection systems.

BACKGROUND

Fiber optic connectors are commonly used in optical fiber communication systems to effect demateable optical connections between waveguides such as optical fibers. A typical optical connection is made by co-axially aligning two optical fibers in end-to-end relation with end faces of the optical fibers opposing one another. To effect optical coupling and minimize Fresnel loss, it is typically preferred for “physical contact” to exist between the optical waveguides, which, in the case of optical connectors, is generally between the opposed end faces of the aligned optical fibers.

Traditionally optical connectors have employed “ferrules.” Ferrules are well-known components, which each hold one or more optical fibers such that the end faces of the optical fibers are presented for optical coupling. For example, traditional single fiber optical connectors such as SC or LC connectors include cylindrical ferrules with optical fibers supported and precisely centered within the ferrules. A traditional multi-fiber optical connector such as an MPO connector can include a ferrule that supports a plurality of optical fibers in a row. In the case of MPO connectors, the ferrules of two fiber optic connectors desired to be coupled together have a mating male and female configuration (e.g., a pin and socket configuration) which aligns the ferrules and concurrently aligns the plurality of optical fibers supported by the ferrules.

Another type of fiber optic connector can be referred to as a ferrule-less fiber optic connector or bare-fiber connector. In a bare-fiber optic connector, an end portion of an optical fiber corresponding to the bare-fiber optic connector is not supported by a ferrule. Instead, the end portion of the optical fiber is a free end portion. Similar to the ferruled connectors described above, fiber optic adapters can be used to assist in optically coupling together two bare-fiber optic connectors. Fiber optical adapters for bare-fiber connectors can include internal fiber alignment devices configured to receive optical fibers of bare-fiber optic connectors desired to be optically coupled together and to align the fiber tips of the fiber optic connectors to enable the transfer of optical signals there between.

SUMMARY

The present disclosure relates generally to a low cost, multi-fiber, semi-permanent, mechanical splicing system. The multi-fiber, semi-permanent, mechanical splicing system includes a minimum number of parts to reduce the costs associated with manufacturing.

In certain examples, the multi-fiber, semi-permanent, mechanical splicing system includes a bare-fiber multi-fiber fiber optic connector. The bare-fiber multi-fiber fiber optic connector includes a connector body and a plurality of optical fibers that extend through the connector body.

In certain examples, the bare-fiber multi-fiber fiber optic connector can include a fiber anchoring chip that mounts within the connector body. The fiber anchoring chip defines a plurality of grooves for receiving the plurality of optical fibers. The plurality of optical fibers can be anchored within the plurality of grooves by an adhesive such as epoxy. In other examples, adhesive may be injected or otherwise positioned in the connector body to secure the optical fibers within the connector body without requiring a fiber anchoring chip or the chip itself may be formed by adhesive.

The multi-fiber, semi-permanent, mechanical splicing system may include a multi-fiber adapter that defines an adapter port for receiving the bare-fiber multi-fiber fiber optic connector.

The multi-fiber, semi-permanent, mechanical splicing system may also include a nose piece mounted on the connector body. The nose piece can be movable along a longitudinal axis between an extended position where fiber ends of the plurality of optical fibers are protected and a retracted position where the fiber ends of the plurality of optical fibers project forwardly beyond the nose piece.

In certain examples, the nose piece can be frictionally held in the retracted position when the bare-fiber multi-fiber fiber optic connector is removed from the adapter port. The nose piece can be manually moved from the retracted position to the extended position. In certain examples, the bare-fiber multi-fiber fiber optic connector does not include a spring or springs for automatically returning the nose piece to the extended position.

The multi-fiber, semi-permanent, mechanical splicing system may include a latching arrangement for securing the bare-fiber multi-fiber fiber optic connector in the adapter port. The bare-fiber multi-fiber fiber optic connector and the multi-fiber adapter lack integrated structures for releasing the bare-fiber multi-fiber fiber optic connector from the adapter port thus making a semi-permanent connection between the bare-fiber multi-fiber fiber optic connector and the multi-fiber adapter.

These and other features and advantages will be apparent from a reading of the following detailed description and a review of the associated drawings. 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 foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad concepts upon which the embodiments disclosed herein are based.

DETAILED DESCRIPTION

FIGS.1-5illustrate an example bare-fiber connection system10in accordance with the principles of the present disclosure. The bare-fiber connection system10includes a first multi-fiber fiber optic connector12, a second multi-fiber fiber optic connector14, and a multi-fiber adapter16. In the depicted example, the first and second multi-fiber fiber optic connectors12,14are bare-fiber multi-fiber fiber optic connectors.

The first and second multi-fiber fiber optic connectors12,14each include a connector body18that has a front end20and a rear end22. The connector body18defines a longitudinal axis X that extends through the connector body18in an orientation that extends from the front end20to the rear end22of the connector body18.

The first multi-fiber fiber optic connector12includes a first plurality of optical fibers24athat extend through the connector body18from the rear end22to the front end20. The second multi-fiber fiber optic connector14includes a second plurality of optical fibers24bthat extend through the connector body18from the rear end22to the front end20. The first and second plurality of optical fibers24a,24bhave fiber ends26(e.g., end portions) that are respectively accessible at the front ends20of the connector bodies18of the first and second multi-fiber fiber optic connectors12,14. In certain examples, the first and second plurality of optical fibers24a,24bmay be ribbonized, buffered, or otherwise contained within a passage of an outer jacket. In the example shown, there are twelve optical fibers24. In certain examples, however, the first and second multi-fiber fiber optic connectors12,14may include a greater or lesser number of optical fibers24(e.g., one fiber, two fibers, six fibers, eight fibers, twenty-four fibers, etc.).

The multi-fiber adapter16can be used to assist in optically coupling together the first and second multi-fiber fiber optic connectors12,14. The multi-fiber adapter16can include opposite first and second adapter ports28,30for respectively receiving the first and second multi-fiber fiber optic connectors12,14to couple the first and second multi-fiber fiber optic connectors12,14together.

The multi-fiber adapter16includes a groove-defining piece32(e.g., internal bare fiber alignment piece)(seeFIG.13) positioned between the first and second adapter ports28,30. The groove-defining piece32defines multiple fiber alignment grooves34(seeFIG.14) for receiving and co-axially aligning the fiber ends26of the first and second plurality of optical fibers24a,24bsuch that optical signals can be conveyed between the first and second plurality of optical fibers24a,24bof the first and second multi-fiber fiber optic connectors12,14.

In certain examples, the first and second multi-fiber fiber optic connectors12,14can each include a strain relief boot36that can be attached to the rear end22of the connector body18by snapping a lip38over a shoulder40and into a retention groove. The strain relief boot36can have a segmented configuration to enhance flexibility.

Turning toFIGS.6-12, the first multi-fiber fiber optic connector12is depicted. The first and second multi-fiber optic connectors12,14are identical. As such, only the first multi-fiber fiber optic connector12will be described in detail. It will be appreciated that the features described herein with reference to the first multi-fiber fiber optic connector12will also apply to the second multi-fiber fiber optic connector14.

The first multi-fiber fiber optic connector12includes a nose piece42mounted at the front end20of the connector body18of the first multi-fiber fiber optic connector12. The nose piece42defines a plurality of fiber passages44through which the plurality of optical fibers24aextend. The plurality of fiber passages44can be v-grooves or other shaped grooves (e.g., half circles, U-shaped grooves, etc.). The nose piece42can be movable along the longitudinal axis X between an extended position (seeFIG.7) where the fiber ends26of the plurality of optical fibers24aare protected within the plurality of fiber passages44and a retracted position (seeFIG.6) where the fiber ends26of the plurality of optical fibers24aproject forwardly beyond the nose piece42.

The connector body18has a first major side46(e.g., top), an opposite, second major side48(e.g., bottom), a first minor side50, and an opposite, second minor side52. In certain examples, at least one of the first and second major sides46,48of the connector body18includes a catch54, although alternatives are possible. The first and second minor sides50,52of the connector body18can each include a rail56, although alternatives are possible.

It will be appreciated by those skilled in the art that in other examples, the first and second major sides46,48of the connector body18can each include the catch54. Also, in other examples, at least one of the first and second minor sides50,52of the connector body18can include the rail56.

The connector body18defines an opening58at the front end20for mounting the nose piece42. Recesses60can be defined within the connector body18on the first and second minor sides50,52thereof. In certain examples, the nose piece42can include latches62that engage the recesses60of the connector body18to be latched therein for retaining the nose piece42in the extended position. The latches62can help to prevent the nose piece42from becoming detached from the connector body18.

The nose piece42can be frictionally held at the front end20of the connector body18because there is no spring. The nose piece42can be held in the retracted position when the first multi-fiber fiber optic connector12is removed from the first adapter port28. The noise piece42is required to be manually moved from the retracted position to the extended position. That is, the first multi-fiber fiber optic connector12does not include a spring or springs for automatically returning the nose piece42to the extended position. In other examples, a spring or spring may be provided, but for cost and sizing purposes it is preferred to not include a spring or springs for returning the nose piece42to the extended position.

In certain examples, the first multi-fiber fiber optic connector12can include a pre-formed structure, such as a fiber anchoring chip64(seeFIG.11), that cooperates with adhesive to bond the plurality of optical fibers24awithin the connector body18. The plurality of optical fibers24acan be inserted through the rear end22of the connector body18, the fiber anchoring chip64can be mounted through the second major side48of the connector body18into a cavity66defined therein to anchor the plurality of optical fibers24a.

In certain examples, the first multi-fiber fiber optic connector12can include a fiber retention structure that is all formed by adhesive. That is, rather than using the pre-formed fiber anchoring chip64, a volume of adhesive can be injected or otherwise positioned within the cavity66for anchoring the optical fibers24. In certain examples, the adhesive can conform to a shape of an interior fiber locking/anchoring region of the connector body.

Still referring toFIG.12, the fiber anchoring chip64defines a plurality of grooves68for receiving the plurality of optical fibers24awhen the fiber anchoring chip64is pushed into the cavity66of the connector body18. Epoxy can be used in combination with the anchoring chip64to anchor the plurality of optical fibers24awithin the plurality of grooves68of the fiber anchoring chip64. By bonding the plurality of optical fibers24a,the plurality of optical fibers24acan be held in an aligned position. In certain examples, the plurality of grooves68of the fiber anchoring chip64can be V-shaped grooves and/or U-shaped grooves, although alternatives are possible.

Turning again toFIG.6, the multi-fiber adapter16includes a first major adapter side70(e.g., top), an opposite, second major adapter side72(e.g., bottom), a first minor adapter side74, and an opposite, second minor adapter side76. In certain examples, latches78can be defined by slots80provided on at least one of the first and second major adapter sides70,72of the multi-fiber adapter16, although alternatives are possible. In certain examples, the latches78can be provided on the first and second minor adapter sides74,76of the multi-fiber adapter16, although alternatives are possible. In certain examples, the latches78can be provided on at least one of the first and second minor adapter sides74,76of the multi-fiber adapter16.

The latches78of the multi-fiber adapter16can each define an aperture82that engages the catch54of the first and second multi-fiber fiber optic connectors12,14as part of a latching arrangement84(seeFIG.13) to allow the first and second multi-fiber fiber optic connectors12,14to be secured (e.g. interlocked) within mating first and second adapter ports28,30, respectively.

The first and second multi-fiber fiber optic connectors12,14and the multi-fiber adapter16lack integrated structures for releasing the first and second multi-fiber fiber optic connectors12,14from the first and second adapter ports28,30. Thus, a semi-permanent connection can be provided between the first and second multi-fiber fiber optic connectors12,14and the multi-fiber adapter16.

As used herein the term “semi-permanent” is intended to mean the multi-fiber fiber optic connectors do not have any release mechanism on them and the multi-fiber adapter does not have any release mechanism on it. Therefore, when the multi-fiber fiber optic connectors are inserted into the multi-fiber adapter, the multi-fiber fiber optic connectors are latched therein such that the only way to release it is with a separate tool that is not on either the multi-fiber fiber optic connectors or the multi-fiber adapter.

Turning toFIGS.13-14, the multi-fiber adapter16can include nose piece releases86that are configured to engage a latch member88of the nose piece42as the first multi-fiber fiber optic connector12is inserted into the first adapter port28. The nose piece releases86can press the latch member88upward to unlatch the nose piece42from the connector body18as the first multi-fiber fiber optic connector12is inserted into the first adapter port28to allow the nose piece42to move from the extended position to the retracted position. The latch member88also prevents the nose piece42from being pushed back into the retracted position before the nose piece42is inserted into the multi-fiber adapter16.

The first and second minor adapter sides74,76can include guide channels90(seeFIG.6) within the first and second adapter ports28,30that receive the rails56of the connector body18as the first multi-fiber fiber optic connector12is inserted into the first adapter port28.

Referring toFIGS.14-16, the groove-defining piece32can define at least a portion of a nose-piece guide92for pre-positioning the nose piece42. As the first and second multi-fiber fiber optic connectors12,14are inserted in respective first and second adapter ports28,30the nose piece42will engage the nose-piece guide92so that the plurality of fiber passages44of the nose piece42can align with the multiple fiber alignment grooves34of the groove-defining piece32. It will be appreciated that other types of bare fiber alignment devices may be alternatively used with the multi-fiber adapter16.

The nose-piece guide92can also function to stop the nose piece42as the first and second multi-fiber fiber optic connectors12,14are inserted in the first and second adapter ports28,30. That is, continued insertion of the first and second multi-fiber fiber optic connectors12,14into the first and second adapter ports28,30, respectively, as shown inFIG.15, causes the nose pieces42to engage the groove-defining piece32as the latch members88are flexed upward by the nose piece releases86. The nose pieces42can be abut the groove-defining piece32of the multi-fiber adapter16.

In certain examples, as the first and second multi-fiber fiber optic connecters12,14are inserted into the first and second adapter ports28,30, the nose pieces42can retract relative to the connector bodies18until the end of the nose pieces42bottoms out against an end wall94of the connector body18(seeFIG.15), although alternatives are possible.

While the front ends of the nose pieces42are in contact with the stop of the nose-piece guide of the groove-defining piece32, the first and second multi-fiber fiber optic connectors12,14can continue to be inserted into the first and second adapter ports28,30causing the connector bodies18to move relative to the nose pieces42such that the plurality of optical fibers24a,24bcan slide through the nose pieces42and project from the plurality of fiber passages44into the multiple fiber alignment grooves34(seeFIG.16). The interface between the nose piece42and the groove-defining piece32can provide pre-alignment of the plurality of optical fibers24a,24bbefore insertion into the multiple fiber alignment grooves34.

Because there is no release mechanism on either the first and second multi-fiber fiber optic connectors12,14or the multi-fiber adapter16, a separate tool can be used to release the first and second multi-fiber fiber optic connectors12,14from the first and second adapter ports28,30. A special tool can be used to move the latches78by flexing the latches78outward to disengage the latches78from the catch54such that the first and second multi-fiber fiber optic connectors12,14can be pulled out of the first and second adapter ports28,30. If, for example, the first multi-fiber fiber optic connector12is removed from the adapter, the nose piece42can be manually pulled back from the retracted to the extended position to provide protection of the optical fibers24. In other examples, friction between the nose piece42and the interior of the multi-fiber adapter16(e.g., a friction/interference fit between the nose piece42and the nose piece guide92) can cause the nose piece42to automatically move from the retracted position to the extended position as the fiber optic connector12,14is removed from its corresponding adapter port.

In certain examples, portions of the optical fibers24may extend beyond the nose piece42when the nose piece42is in the retracted position. In preferred examples, the portions of the optical fibers24that project forwardly beyond the nose piece42when the nose piece42is retracted are bare fiber portions (e.g., fiber portions with only a core and cladding). In certain examples, the bare fiber portions project at least 3, 4, 5 or 6 millimeters beyond the nose piece42when the nose piece42is fully retracted, although alternatives are possible.

Referring toFIGS.17-23, another example bare-fiber connection system10ais depicted in accordance with the principles of the present disclosure. The bare-fiber connection system10ais similar to the bare-fiber connection system10previously described except the design has a lower profile. That is, the bare-fiber connection system10ahas a lower height construction compared with the bare-fiber connection system10.

The bare-fiber connection system10aincludes a multi-fiber adapter16athat functions similar to the multi-fiber adapter16described above. However, in order to accommodate the lower profile design of the first and second multi-fiber fiber optic connectors12a,14a,the multi-fiber adapter16ais configured with latches78apositioned on the first and second minor adapter sides74a,76aopposed to being on the first and second major adapter sides70a,72a.Also, the catches54aof the connector bodies18aare positioned on the first and second minor sides50a,52aof the first and second multi-fiber fiber optic connectors12a,14ato reduce the overall height and provide a low profile system. The latches78aare adapted to interface with the catches54aof the first and second multi-fiber fiber optic connectors12a,14awhen the first and second multi-fiber fiber optic connectors12a,14aare inserted into adapter port openings28a,30a.The multi-fiber adapter16ahas low profile or lower height adapter port openings28a,30ato correspond with the low profile design of the first and second multi-fiber fiber optic connectors12a,14a.

The multi-fiber adapter16aincludes an example groove-defining piece32a.In certain examples, the groove-defining piece32acan include multiple stacks of alignment devices, although alternatives are possible. The groove-defining piece32adefines multiple fiber alignment grooves34afor receiving and co-axially aligning optical fibers24a,24bof the first and second multi-fiber fiber optic connectors12a,14ato provide an optical connection therebetween.

Referring toFIGS.24-28, the first and second multi-fiber fiber optic connectors12a,14acan each define a cavity66for receiving an adhesive material such as epoxy to bond the optical fibers24a,24bwithin respective connector bodies18a.In certain examples, the cavity66may receive a fiber anchoring chip or other structure that can assist in bonding the optical fibers24within respective connector bodies18a.

The first and second multi-fiber fiber optic connectors12a,14acan also include nose pieces42athat do not have springs for automatically returning the nose pieces42ato the extended positions. The nose pieces42ahave a low profile and preferably mount at the front end20of the connector body18aof the first and second multi-fiber fiber optic connectors12a,14a.The nose pieces42adefine a plurality of fiber passages44through which the plurality of optical fibers24a,24bextend. The nose pieces42acan be movable along the longitudinal axis X between an extended position (seeFIG.28) where the fiber ends26of the plurality of optical fibers24a,24bare protected within the plurality of fiber passages44and a retracted position (seeFIG.23) where the fiber ends26of the plurality of optical fibers24a,24bproject forwardly beyond the nose pieces42a.

Referring toFIGS.29-32, an alternative connector body18bis depicted that can be used in the bare-fiber connection systems10,10apreviously described. The connector body18ballows an installer to field terminate the optical fibers24by clamping the optical fibers24between a first housing piece96and a second housing piece98. The connector body18bprovides an installation displacement system that secures the optical fibers24in place to prevent stripping of the fibers and allows for further processing such as, cleaving etc. In certain examples, the first and second housings pieces96,98do not require adhesive such as epoxy to anchor the optical fibers in place, but in other examples adhesive may be used as well.

In certain examples, a clip100can be provided on the first housing piece96to help retain the connector body18bin a fiber optic adapter. The clip100may be a spring-loaded clip.

It will be appreciated that the connector body18bcan be used with the nose pieces42,42apreviously described. The nose pieces42,42acan be mounted to the first and second housing pieces96,98. The nose pieces42,42bdefine a plurality of fiber passages44through which the plurality of optical fibers24extend.

The first housing piece96defines a plurality of first grooves102(seeFIG.32) and the second housing piece98defines a plurality of second grooves104(seeFIG.31) that oppose the plurality of first grooves102when the first and second housing pieces96,98are mounted together such that the plurality of first and second grooves102,104cooperate together to define a plurality of fiber channels106(seeFIG.34). The first housing piece96includes latches108on opposing sides thereof that engage catches110on opposing sides of the second housing piece98to connect the first and second housing pieces96,98together. That is, the first and second housing pieces96,98can be joined together by a snap-fit connection. In other examples, the first and second housing pieces96,98may be pivotally attached together, although alternatives are possible.

Referring toFIGS.35-36, the optical fibers24can include an optical core112surrounded by a cladding layer114. In certain examples, one or more acrylate coating layers116may surround the cladding layer114within the connector body18b,but preferably end portions26are uncoated. The optical core112and the cladding layer114can have different indexes of refraction that are selected to cause light to propagate through the optical fiber via total internal reflection.

Optical fibers can include single mode optical fiber and multi-mode optical fibers. Generally, single mode optical fibers have smaller cores than multi-mode optical fibers. For example, a traditional single mode optical fiber has a core with a diameter in the range of 8-10 microns and a cladding layer with an outer diameter in the neighborhood of 125 microns. In contrast, multi-mode optical fibers transitionally have cores with diameters of about 50 microns or about 62.5 microns, and cladding layers with outer diameters of about 125 microns. The acrylate coating layer116is typically 200-260 microns in outer diameter. Aspects of the present disclosure are applicable to both single mode and multi-mode optical fibers.

Turning toFIGS.37-38, the optical fibers24are positioned prior to being inserted within the plurality of first grooves102of the first housing piece96. The plurality of first grooves102include a first groove section118sized and shaped to support the cladding layer114of the optical fibers24and a second groove section120sized and shaped to support the acrylate coating layer116of the optical fibers24. When the first and second housing pieces96,98are connected together, the optical fibers24can be anchored within the connector body18bby a clamping action.

Referring toFIGS.39-40, the first and second housing pieces96,98are shown connected together with the optical fibers24clamped therebetween. The plurality of fiber channels106include a first set of teeth122and a second set of teeth124. The first set of teeth122and the second set of teeth124can have different sizes. In certain examples, the first set of teeth122are larger than the second set of teeth124.

When the first and second housing pieces96,98are mated together to clamp the optical fibers24therebetween, the first set of teeth122can penetrate the coating layers116of the optical fibers24and engage the cladding layers114of the optical fibers24to axially fix the optical fibers24.

When the first and second housing pieces100,102are mated together to clamp the optical fibers96therebetween, the second set of teeth124can embed in the coating layers118of the optical fibers96but do not engage the cladding layers116of the optical fibers96. The second set of teeth124can hold the acrylate coating layer118with enough force such that the acrylate coating layer118can be held tight to the glass core114and not strip off under axial load. In certain examples, the first set of teeth122axially fix the glass portions of the optical fibers96relative to the housing pieces100,102, while the second set of teeth124provide additional clamping force for axially fixing the fiber coatings relative to the housing pieces100,102and/or the glass portions of the optical fibers96.

From the forgoing detailed description, it will be evident that modifications and variations can be made without departing from the spirit and scope of the disclosure.