WO2022055773A1 - High density stacked alignment devices - Google Patents

Abstract

The present disclosure relates to devices and systems for co-axially aligning first and second optical fibers to provide an optical coupling between the first and second optical fibers. A biasing component is provided to translate spring biasing force sequentially through a stackable fiber alignment device within a multi-fiber adapter to bias optical fibers into parallel alignment grooves.

Description

HIGH DENSITY STACKED ALIGNMENT DEVICES

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is being filed on September 1, 2021, as a PCT International Patent Application and claims the benefit of U.S. Patent Application Serial No. 63/078,097, filed on September 14, 2020, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to multi-fiber connectivity. More particularly, the present disclosure relates to fiber optic connection components such as multi-fiber fiber optic alignment devices.

BACKGROUND

Fiber optic communication systems are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities (e.g., data and voice) to customers. Fiber optic communication systems employ a network of fiber optic cables to transmit large volumes of data and voice signals over relatively long distances. Optical fiber connectors are an important part of most fiber optic communication systems. Fiber optic connectors allow two optical fibers to be quickly optically connected without requiring a splice. Fiber optic connectors can be used to optically interconnect two lengths of optical fiber. Fiber optic connectors can also be used to interconnect lengths of optical fiber to passive and active equipment.

A typical fiber optic connector includes a ferrule assembly supported at a distal end of a connector housing. A spring is used to bias the ferrule assembly in a distal direction relative to the connector housing. The ferrule functions to support an end portion of at least one optical fiber (in the case of a multi-fiber ferrule, the ends of multiple fibers are supported). The ferrule has a distal end face at which a polished end of the optical fiber is located. When two fiber optic connectors are interconnected, the distal end faces of the ferrules abut one another and the ferrules are forced proximally relative to their respective connector housings against the bias of their respective springs. With the fiber optic connectors connected, their respective optical fibers are coaxially aligned such that the end faces of the optical fibers directly oppose one another. In this way, an optical signal can be transmitted from optical fiber to optical fiber through the aligned end faces of the optical fibers. For many fiber optic connector styles (LC, SC, MPO), alignment between two fiber optic connectors is provided through the use of an intermediate fiber optic adapter.

Another type of fiber optic connector can be referred to as a ferrule-less fiber optic connector or bare fiber optic 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, bare fiber optic adapters can be used to assist in optically coupling together two bare fiber optic connectors. Example bare fiber optic connectors and/or bare fiber optic adapters are disclosed by PCT Publication Nos.

WO 2012/112344; WO 2013/117598; WO 2017/081306; WO 2016/100384;

WO 2016/043922; and U.S. Patent Nos. 8,870,466 and 9,575,272.

Fiber optical adapters are used to optically couple together optical fiber tips of optical connectors. Fiber optical adapters can include specialized fiber alignment devices to receive bare optical fibers and align the fiber tips to enable the transfer of optical signals therebetween. Optical connectors can be secured to the optical adapters when received at the ports of the optical adapters.

SUMMARY

Aspects of the present disclosure relate to a stackable alignment structure to improve density within a multi-fiber adapter and overall connector system. The stackable alignment structure is advantageous for aligning sets of multiple optical fibers of multifiber optical connectors to provide high optical connection densities.

In certain examples, the stackable alignment structure can be configured to accommodate multiple rows of optical fibers positioned within a fiber optic holder.

In certain examples, the stackable alignment structure can be configured to accommodate fiber optic connectors that include at least eight, twelve, sixteen, twenty- four, thirty-two, forty-eight, or more optical fibers.

One aspect of the present disclosure relates to a bare fiber multi-fiber alignment device for aligning a plurality of optical fibers of bare fiber optic connectors that include a biasing component (e.g., spring) for transferring a spring load/force through multiple layers of a bare fiber multi-fiber alignment device in order to hold pairs of rows of a plurality of optical fibers into alignment structures such as fiber alignment grooves.

The spring load/force can be applied by positioning the biasing component at one side of the bare fiber multi-fiber alignment device such that no intermediate spring or springs are positioned between the multiple flexible layers of the bare fiber multi-fiber alignment device.

In certain examples, the biasing component is a leaf spring. In other examples, more than one spring may be provided.

Another aspect of the present disclosure relates to a stackable multi-fiber alignment device for co-axially aligning multiple rows of first and second bare optical fibers to provide an optical coupling between the multiple rows of first and second bare optical fibers. The stackable multi-fiber alignment device can include a support structure that defines a receptacle for receiving a biasing component.

The stackable multi-fiber alignment device can also include a first stacking member that defines a first array of parallel fiber alignment grooves in a first surface thereof. Each of the first array of parallel fiber alignment grooves can be configured for receiving a first pair of rows of the first and second bare optical fibers.

The stackable multi-fiber alignment device can also include a second stacking member moveable relative to the first stacking member. The second stacking member can define a second array of parallel fiber alignment grooves in a first surface thereof. Each of the second array of parallel fiber alignment grooves can be configured for receiving a second pair of rows of the first and second bare optical fibers.

The support structure and the first and second stacking members can be coupled together by a securement arrangement that maintains forcible contact between the first and second surfaces of the first and second stacking members.

When the support structure and the first and second stacking members are coupled together within a multi-fiber optic adapter, the biasing component can be configured to transfer spring load sequentially through the support structure and the first and second stacking members to respectively bias the first and second pairs of rows of the first and second bare optical fibers into the first and second arrays of parallel fiber alignment grooves.

A variety of additional aspects will be set forth in the description that follows. The 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 inventive concepts upon which the examples disclosed herein are based.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows:

FIG. 1 is a schematic view depicting a fiber optic connection system in accordance with the principles of the present disclosure, the fiber optic connection system including first and second bare fiber optic connectors having multiple rows of bare optical fibers shown prior to insertion into a stackable multi-fiber alignment device of a multifiber adapter;

FIG. 2 is a perspective view of the stackable multi-fiber alignment device of FIG. 1;

FIG. 3 is another perspective view of the stackable multi-fiber alignment device of FIG. 1 showing the first and second bare fiber optic connectors removed;

FIG. 4 is an exploded view of the stackable multi-fiber alignment device of FIG. 3 from a top perspective;

FIG. 5 is an exploded view of the stackable multi-fiber alignment device of FIG. 3 from a bottom perspective;

FIG. 6 is a top view of the stackable multi -fiber alignment device of FIG. 3;

FIG. 7 is a cross-sectional view taken along section line 7-7 of FIG. 6;

FIG. 8 is an enlarged view of a portion of FIG. 7;

FIG. 9 is a cross-sectional view taken along section line 9-9 of FIG. 6;

FIG. 10 is an enlarged view of a portion of FIG. 9;

FIG. 11 is an exploded view of multiple stacking layers of the stackable multi-fiber alignment device of FIG. 3;

FIG. 12 is an enlarged view of a portion of FIG. 11;

FIG. 13 is a schematic view of the multi-fiber adapter and the stackable multi-fiber alignment device of FIG. 1 prior to mounting a cover over a biasing component in accordance with the principles of the present disclosure;

FIG. 14 is a schematic view of the cover of FIG. 13 pressing down the biasing component to transfer spring load sequentially through the stackable multi-fiber alignment device in accordance with the principles of the present disclosure; FIG. 15 is a perspective view of another stackable multi -fiber alignment device in accordance with the principles of the present disclosure;

FIG. 16 is a transverse cross-sectional view of the stackable multi-fiber alignment device of FIG. 15; and

FIG. 17 is an enlarged view of a portion of the stackable multi-fiber alignment device of FIG. 16.

DETAILED DESCRIPTION

Aspects of the present disclosure relates to fiber optic connection systems for aligning optical fibers of bare fiber multi -fiber optic connectors to provide optical connections between the multiple rows of optical fibers of the fiber optic connectors.

Alignment systems in accordance with the principles of the present disclosure can include stackable multi-fiber alignment devices for co-axially aligning optical fibers to provide optical connections between the aligned optical fibers. The alignment devices can define alignment grooves for receiving and aligning the optical fibers. The alignment grooves can be defined by stacking structures such as members which each define an array of parallel grooves. The stacking structures can include plates which may have a ceramic construction, a metal construction, a plastic construction or other constructions.

The alignment grooves can include grooves having v-shaped cross-sections (e.g., v-grooves) grooves having u-shaped cross-sections, grooves having through-shaped cross-sections, grooves having half-circle shaped cross-sections or grooves having other shapes. In certain examples, index matching gel can be used between opposing ends of optical fibers aligned within the alignment devices.

FIG. 1 schematically depicts a fiber optic connection system 10 in accordance with the principles of the present disclosure. The fiber optic connection system 10 includes a first multi-fiber fiber optic connector 12, a second multi-fiber fiber optic connector 14 and a multi-fiber optic adapter 16. The first and second multi-fiber fiber optic connectors 12, 14 can be configured to terminate separate multi-fiber cables (not shown) having optical fibers desired to be optically coupled together. The first and second multi-fiber fiber optic connectors 12, 14 are bare fiber multi-fiber fiber optic connectors. The first and second multi-fiber fiber optic connectors 12, 14 each include a connector body 18 (e.g., housing) that encloses rows 20a-c (e.g., two rows, three rows, four rows, five rows, six rows, seven rows, eight rows, etc.) of first and second optical fibers 22a, 22b of the multi-fiber cables. The example depicted includes a first pair of rows 20a of the first and second optical fibers 22a, 22b, a second pair of rows 20b of the first and second optical fibers 22a, 22b, and a third pair of rows 20c of the first and second optical fibers 22a, 22b.

In certain examples, each first, second, and third pair of rows 20a-c can include twelve optical fibers 22a, 22b such that the first and second multi-fiber fiber optic connectors 12, 14 are each 36 fiber connectors, although alternatives are possible. In other examples, each pair of rows 20a-c can include a greater or lesser number of fibers 22a, 22b (e.g., sixteen fibers, twenty-four, thirty-two, forty-eight, or more optical fibers etc.).

The multi-fiber adapter 16 can include a stackable multi -fiber alignment device 24 for co-axially aligning the pairs of rows 20a-c of the first and second optical fibers 22a, 22b corresponding to the first and second multi-fiber fiber optic connectors 12, 14 to provide an optical coupling therebetween. The first and second optical fibers 22a, 22b can respectively extend forwardly through the connector body 18 of the first and second multi-fiber fiber optic connectors 12, 14 such that bare end portions 26 of the first and second optical fibers 22a, 22b are accessible at a front mating end 28 of the connector body 18.

Still referring to FIG. 1, the multi -fiber adapter 16 includes an adapter body 30 that defines a first port 32 for receiving the first multi-fiber fiber optic connector 12 and a second port 34 for receiving the second multi -fiber fiber optic connector 14. The first and second multi-fiber fiber optic connectors 12, 14 are shown prior to insertion into the first and second adapter ports 32, 34, respectively. The multi-fiber adapter 16 can be used to assist in optically coupling together the first and second multi-fiber fiber optic connectors 12, 14. The first and second multi-fiber optic connectors 12, 14 can be coupled together by inserting the first and second multi-fiber optic connectors 12, 14 within coaxially aligned ports 32, 34 of the multi -fiber adapter 16. Continued insertion of the first and second multi-fiber optic connectors 12, 14 causes the bare end portions 26 of the first and second optical fibers 22a, 22b to enter the stackable multi-fiber alignment device 24.

Referring to FIGS. 2-3, the stackable multi-fiber alignment device 24 is depicted with the first and second multi-fiber fiber optic connectors 12, 14 depicted schematically in hidden line in FIG. 2.

In certain examples, the stackable multi-fiber alignment device 24 can include multiple components arranged in a stacked configuration to accommodate multiple parallel rows of optical fibers. In certain examples, the stackable multi-fiber alignment device 24 can include a support structure 36 (e.g., a top piece, a spring support piece), a first stacking member 38 (e.g., a first intermediate piece), a second stacking member 40 (e.g., a second intermediate piece), and a third stacking member 42 (e.g., a base piece), although alternatives are possible. It will be appreciated that the multi-fiber alignment device 24 may include a greater or lesser number of stacking members.

The first, second, and third stacking members 38, 40, 42 may each define an array of parallel fiber alignment grooves 44. That is, the first stacking member 38 may define a first array of parallel fiber alignment grooves 44a in a first surface 46 (e.g., a top surface) thereof, the second stacking member 40 may define a second array of parallel fiber alignment grooves 44b in a first surface 48 (e.g., a top surface) thereof, and the third stacking member 42 may define a third array of parallel fiber alignment grooves 44c in a first surface 50 (e.g., a top surface) thereof.

As used herein, the term, “groove,” is defined generally as an elongate structure that can receive and support an optical fiber. In one example, the elongate structure can have two surfaces that are angled such that when an optical fiber lies within the groove, the optical fiber makes line contact with the two surfaces. The elongate structure can be defined by one component (e.g., a groove in a substrate such as a plate). Generally a groove will have an open side and a closed side in which an optical fiber sits. In one example, the groove may include a v-groove that has angled surfaces. In such an example, the v-groove will have a structure that preferably provides two lines of contact with an optical fiber inserted therein. In this way, the line/point contact with the v-groove assists in providing accurate alignment of the optical fibers. Other grooves having relatively angled surfaces adapted to make two lines of contact with each fiber can also be used.

The first, second, and third arrays of fiber alignment grooves 44a-c can include grooves that have v-shaped cross-sections (e.g., v-grooves), grooves that have u- shaped cross-sections, grooves that have through-shaped cross-sections, grooves that have half-circle shaped cross-sections or grooves that have other shapes.

The first, second, and third stacking members 38, 40, 42 can be referred to as a groove-defining structure (e.g., groove-defining plate), can be constructed of plastic, metal, ceramic or other materials, and can be manufactured by molding, casting, machining, etching or other process. The pair of rows 20a-c of the bare end portions 26 of the first and second optical fibers 22a, 22b are shown respectively inserted into the first, second, and third arrays of parallel fiber alignment grooves 44a-c of the first, second, and third stacking members 38, 40, 42 of the stackable multi -fiber alignment device 24.

Turning to FIG. 4, the first array of parallel fiber alignment grooves 44a can be configured to receive and align the first pair of rows 20a of the bare end portions 26 of the first and second optical fibers 22a, 22b. The second array of parallel fiber alignment grooves 44b can be configured to receive and align the second pair of rows 20b of the bare end portions 26 of the first and second optical fibers 22a, 22b. The third array of parallel alignment grooves 44c can be configured to receive and align the third pair of rows 20c of the bare end portions 26 of the first and second optical fibers 22a, 22b.

The first, second, and third arrays of parallel fiber alignment grooves 44a-c of the first, second, and third stacking members 38, 40, 42 each include opposite ends 52, 54 into which the bare end portions 26 of the first and second optical fibers 22a, 22b are respectively inserted. The bare end portions 26 of the first and second optical fibers 22a, 22b can be inserted into the first, second, and third arrays of parallel fiber alignment grooves 44a-c along a fiber insertion axis 56 that extends along the first, second, and third arrays of parallel fiber alignment grooves 44a-c.

The bare end portions 26 of the first and second optical fibers 22a, 22b received within the fiber alignment grooves 44a-c are preferably bare fibers. As used herein, a bare fiber is a section of optical fiber that does not include any coating. Instead, the bare fiber includes a core surrounded by a cladding layer. The optical fiber is “bare” because the cladding layer is exposed and not covered by a supplemental coating layer such as acrylate.

When the first and second multi-fiber fiber optic connectors 12, 14 are fully inserted/loaded into the multi -fiber adapter 16, the first and second optical fibers 22a, 22b are received within the opposite ends 52, 54 of the first, second, and third arrays of parallel fiber alignment grooves 44a-c and end faces of the first and second optical fibers 22a, 22b oppose one another at an optical interface reference location 58. The optical interface reference location 58 is the location where an optical interface (i.e. , optical connection) is made between the first and second optical fibers 22a, 22b when the first and second optical fibers 22a, 22b are aligned within the first, second, and third arrays of parallel fiber alignment grooves 44a-c. In certain examples, the ends of the opposite rows of optical fibers make physical contact with one another at the optical interface reference location 58.

It will be appreciated that the end faces of the first and second optical fibers 22a, 22b are located at tips of the first and second optical fibers 22a, 22b. With the first and second optical fibers 22a, 22b inserted within the first, second, and third arrays of parallel fiber alignment grooves 44a-c, the end faces of the first and second optical fibers 22a, 22b are aligned (e.g., co-axially aligned) to oppose one another. In one example, the end faces can physically contact one another at the optical interface reference location 58. In another example, a space can exist between the end faces at the optical interface reference location 58. If such space is present, it is preferably filled with an index matching gel to enhance optical performance.

The support structure 36 can be coupled with the first, second, and third stacking members 38, 40, 42 by a securement arrangement 60. That is, the securement arrangement 60 can be configured to sandwich the support structure 36 together with the first, second, and third stacking members 38, 40, 42 to maintain a biasing contact therebetween.

In certain examples, the securement arrangement 60 can include guides 62 (e.g., posts, extensions, pegs) that project downwardly from opposing side walls 64, 66 of the support structure 36 are located adjacent comers of the support structure 36. The guides 62 can be configured to fit into notches 68 (e.g., openings) defined at opposing sides 70, 72 of each of the first, second, and third stacking members 38, 40, 42 to form the securement arrangement 60. The securement arrangement 60 can be configured to provide nesting interfaces, mating interfaces, or overlapping interfaces between the first, second, and third stacking members 38, 40, 42. The guides 62 can provide an alignment function that aligns the stacking members 38, 40, 42 with respect to each other along two dimensions (e.g., x and y dimensions shown at FIG. 5) while allowing relative movement between the stacking members 38, 40, 42 along a third dimension (e.g., z dimension as shown at FIG. 5) perpendicular with respect to the first and second dimensions. It will appreciated that additional stacking members may be provided in the stackable multi-fiber alignment device 24. The guides 62 of the support structure 36 would need to be extended to support the number of layers added.

When the third stacking member 42 is loaded into the multi-fiber adapter 16, the third stacking member 42 can rests on a bed of the multi -fiber adapter 16 to be support thereon which helps to prevent the third stacking member 42 from moving away from the remainder of the stacking members 38, 40 in a direction along the third dimension (e.g., the z dimension as shown at FIG. 5). As such, the entire stack can be supported on the bed of the multi -fiber adapter 16. Intermediate first and second stacking members 38, 40 can be sandwiched between the support structure 36 and the third stacking member 42. The support structure 36 preferably moves relative to the third stacking member 42 so that spring load can be transferred through the entire stack to the bottom stacking member 42. When spring load is applied to the support structure 36 along the third dimension in a direction toward the remainder of the stack (e.g., a downward direction), the stacking members 38, 40, and 42 are compressed between the support structure 36 and the bed of the multi-fiber adapter 16. The ability of the stacked members to slide relative to one another combined with the flexibility of the individual layers allows spring load to be transferred through the entire stack. In other examples, the stacking members 38, 40, and 42 may have flexible constructions that allow the stacking members to flex to transfer load through the stack without requiring sliding.

Turning to FIG. 5, the third stacking member 42 can have a first thickness Ti and the first and second stacking members 42 can have a second thickness T2. In certain examples, the first thickness Ti of the third stacking member 42 is greater than the second thickness T2 of the first and second stacking members 38, 40, although alternatives are possible. In certain examples, the first thickness Ti is equal to the second thickness T2. In other examples, the first thickness Ti is less than the second thickness T2.

The third stacking member 42 can have a greater thickness compared with the first and second stacking members 38, 40 to allow the third stacking member 42 to function as a support member. That is, the third stacking member 42 may not be flexible relative to the first and second stacking members 38, 40 to prevent the stackable multifiber alignment device 24 from bowing. In other examples, the third stacking member 42 may be flexible if the stackable multi-fiber alignment device 24 is positioned upon a rigid surface to provide support for the stackable multi-fiber alignment device 24.

The first, second, and third stacking members 38, 40, 42 each have a respective second surfaces 74, 76, 78 opposite first surfaces 46, 48, 50. The second surfaces 74, 76 of respective first and second stacking members 38, 40 can be configured as fiber contact sides. For example, the second surfaces 74, 76 of the first and second stacking members 38, 40 are fiber contact sides 80 that oppose open sides of the second and third arrays of parallel fiber alignment grooves 44b-c when the first, second, and third stacking members 38, 40, 42 are coupled together. The fiber contact sides 80 are each adapted to engage both the first and second optical fibers 20a, 20b when the first and second optical fibers 20a, 20b are optically coupled together in the fiber alignment grooves 44b-c.

The support structure 36 defines a receptacle 82 for receiving a biasing component 84 (e.g., a spring, a leaf spring,). The receptacle 82 can be defined by a pressing member 86 (e.g., pressing element, contact member, contact element) that forms a base 88 (e.g., bottom side) and a plurality of walls 90 extending upwardly from the base 88. The base 88 can include independently moveable pressing members 86a formed by slots 92 defined in the support structure 36.

The independently moveable pressing members 86 can correspond with each of the first array of parallel fiber alignment grooves 44a of the first stacking member 38. The pressing members 86 are each adapted to oppose open sides of the first array of parallel fiber alignment grooves 44a when the support structure 36 is coupled with the first stacking member 38. Bottom sides of the pressing members 86 can engage bare end portions 26 of the first and second optical fibers 20a, 20b when the first and second optical fibers 20a, 20b are optically coupled together in the fiber alignment grooves 44a of the first stacking member 38.

Turning again to FIGS. 2-3, the biasing component 84 can have a one-piece unitary construction. The biasing component 84 can be made of sheet metal which can start in a flat sheet-like configuration (e.g., stamped sheet metal) and be manufactured by bending the flat sheet-like configuration to the desired shape (see FIGS. 4-5). The biasing component 84 may define slots 94 that correspond with the slots 92 of the pressing member 86 when the biasing component 84 is positioned within the receptacle 82 of the support structure 36.

The biasing component 84 can include a solid perimeter about the slots 94 such that the slots 94 extend only partially longitudinally between first and second ends 13, 15 of the biasing component 84. As such, the pressing member 86 can have a solid portion 17 that surrounds the slots 94 to allow the center of the biasing component 84 to flex. The biasing component 84 includes major sides 96 that each include a tab 98 to retain the biasing component 84 within the receptacle 82 of the support structure 36.

The support structure 36 can include intermediate wall portions 100 that can be positioned inwardly from the walls 90 at major sides thereof to abut the biasing component 84 when the biasing component 84 is mounted in the receptacle 82 of the support structure 36. The intermediate wall portions 100 of the support structure 26 each define a recess 102 for respectively receiving the tab 98 of the biasing component 84 when the biasing component 84 is positioned within the receptacle 82.

Referring to FIGS. 6-10, each of the fiber alignment grooves 44a-c of the support structure 36 and the first, second, and third stacking members 38, 40, 42 can include a lead-in surface 104 for guiding the first and second optical fibers 22a, 22b into the respective fiber alignment grooves 44a-c.

The fiber alignment grooves 44a-c of the first, second, and third stacking members 38, 40, 42 can be separated by precision standoffs or spacing posts 106. As such, when the support structure 36 and the first, second, and third stacking members 38, 40, 42 are coupled together inside a multi-fiber adapter, the first and second stacking members 38, 40 can rest on the standoffs 106 such that when stacked, the stacking members engage one another at specific contact locations. The first, second, and third stacking members 38, 40, 42 can each be separated from each other by the standoffs/posts 106. The standoffs 106 can define a spacing between the alignment grooves 44a-c and the fiber contact sides 80 which is selected to allow the bare end portions 26 to be inserted into the alignment grooves 44 with contact being provided between the fiber 22 and the fiber contact sides 80 as well as the surfaces defining the alignment grooves 44a-c. Thus, the fibers 22a, 22b are pressed within the alignment grooves 44 by the contact sides 80 with the assistance of spring load provided by the biasing component 84. The standoffs 106 can be sized to correspond to a particular fiber size (e.g., 250 microns). To accommodate smaller fiber sizes (e.g., 200 microns), the standoffs 106 can be shortened or eliminated.

Turning to FIGS. 11-12, comers 110 of the first, second, and third stacking members 38, 40, 42 can be slightly raised compared to their respective first surfaces 46, 48, 50. A cutout region 112 can be defined in the first surfaces 46, 48, 50 of the respective first, second, and third stacking members 38, 40, 42 to define the raised comers 110. The cutout region 112 in the top of each of the first, second, and third stacking members 38, 40, 42 can provide clearance or gaps 108 (see FIG. 10). That is, the gaps 108 can be formed between the support structure 36 and the first stacking member 38, between the first stacking member and the second stacking member 40, and between the second stacking member 40 and the third stacking member 42. The gaps 108 can be provided along the sides of the stacking members 38, 40, 42 to provide clearance at the sides of the stacking members 38, 40, 42 that assists in allowing the members 26, 38, and 40 to be capable of flexing slightly in the regions that extend longitudinally between the stand-offs 106 in response to spring load.

In certain examples, the comers 110 of the support structure 36 and the first and second stacking members 38, 40 can have solid or rigid construction while the center flexes. That is, the support structure 36 and the first and second stacking members 38, 40 can still be configured to flex in the center to press on the optical fibers 22a, 22b of the layer below as a result of force from the biasing component 84.

The fiber alignment grooves 44a-c of the first, second, and third stacking members 38, 40, 42 can provide a horizontal center-to-center spacing (e.g., pitch) between the optical fibers 22a, 22b of each row to achieve a desired pitch of, for example, 250 micrometers or 200 micrometers, although alternatives are possible. In certain examples, the stackable multi -fiber alignment device 24 has a pitch of less than or equal to 3 millimeters or less than or equal to 2.95 millimeters between the rows of first and second optical fibers 22a, 22b along a vertical axis.

Referring to FIGS. 13-14, the stackable multi-fiber alignment device 24 is schematically shown in a cross-sectional view within the multi-fiber adapter 16. The biasing component 84 is positioned at the top of the stackable multi-fiber alignment device 24. In certain examples, more than one (e.g., two or more) of biasing components 84 can be provided.

The internal inherent resiliency (i. e. , spring-like characteristics) of the biasing component 84 can generate the spring biasing load/force that translates through the support structure 36 and the first and second stacking members 38, 40 for pressing the optical fibers 22a, 22b into their corresponding fiber alignment grooves 44a-c. The optical fibers 22a, 22b may contact the support structure 36 and the first and second stacking members 38 40 at their respective bottom sides upon insertion of the optical fibers 22a, 22b into the alignment groove 44a-c.

The support structure 36 and the first, second, and third stacking members 38, 40, 42 can be arranged in a stacked relationship within the multi-fiber adapter 16 and are adapted to cooperate to apply spring load from the biasing component 84 to the optical fibers 22a, 22b in their respective fiber alignment grooves 44a-c. In certain examples, the spring biasing force can be generated by two or more biasing components 84.

The support structure 36, the first stacking member 38, the second stacking member 40, and the third stacking member 42 can be compressed together within the multi-fiber adapter 16. An adapter cover 114 may be mounted to the multi-fiber adapter 16 to engage the stackable multi-fiber alignment device 24 positioned therein. The adapter cover 114 can be configured to fit within the receptacle 82 of the support structure 36. As the adapter cover 114 is placed into the receptacle 82, the adapter cover 114 can be configured to press down on the biasing component 84 to cause the biasing component 84 to flatten. When the biasing component 84 is flattened by the adapter cover 114, the biasing component 84 can apply a spring load/force 81 to that transfers sequentially through the support structure 36 and the first and second stacking members 38, 40. The biasing component 84 can be configured to apply a spring force 13 to each of the support structure 36 and the first and second stacking members 38, 40 to cause these layers to bend, flex, or translate in order to bias the first and second optical fibers 22a, 22b into their respective fiber alignment grooves 44a-c.

The biasing component 84 can apply biasing spring force to each of the support structure 36 and the first and second stacking members 38, 40 that causes the support structure 36 and the first and second stacking members 38, 40 to bend, flex, or translate. The support structure 36, the first stacking member 38, and the second stacking member 40 can each function as an intermediate force transfer member for transferring the spring force from the biasing component 84. As such, no other spring or springs are positioned between the first, second, and third stacking members 38, 40, 42 to provide a biasing spring force.

The first stacking member 38 and the second stacking member 40 can flex relative to the support structure 36 to apply a spring force to both of the first and second optical fibers 22a, 22b aligned in respective fiber alignment grooves 44a-c of the first, second, and third stacking members 38, 40, 42. That is, spring biasing forces generated by the biasing member 84 can be transferred through the support member 36 and the first and second stacking members 38, 40 to be distributed and applied to the corresponding optical fibers 22a, 22b to bias the first and second optical fibers 22a, 22b into their respective fiber alignment grooves 44a-c. Therefore, spring load from the biasing member 84 can be applied to the optical fibers 22a, 22b indirectly by the support structure 36 and the first and second stacking members 38, 40 rather than directly by the biasing member 84.

It will be appreciated that the stackable multi-fiber alignment device 24 can be built to accommodate a variety of different fiber counts. In certain examples, additional stacking members can be assembled together as intermediate pieces to build the multi-fiber alignment device 24. Because the biasing member 84 can be positioned at the top of the multi-fiber alignment device 24 and not between the stacking members, a higher density alignment system can be achieved that is smaller or more compact. Additional stacking members can provide additional rows of usable fiber alignment grooves that can accommodate more optical fibers 22a, 22b desired to be mated together. Typically, a rigid groove-defining component can define a base of the multi-fiber alignment device 24. In other examples, the base can be defined by a separate solid surface that is not a component of the multi-fiber alignment device 24.

Referring to FIGS. 15-17, another example stackable multi-fiber alignment device 24a is depicted in accordance with the principles of the present disclosure. The stackable multi -fiber alignment device 24a has similar features as the stackable multi-fiber alignment device 24 previously described except there is no cutout region 112 in the first, second, and third stacking members 38a, 40a, 42a. Additionally, the embodiment of FIGS. 15-17 can be configured with a biasing structure that is designed to be actuated to apply spring load to the fiber alignment stack after the rows of optical fibers have already been inserted in their respective grooves. This type of design greatly reduces the insertion force required to axially insert the optical fibers within their respective alignment grooves.

Because no clearance or gap is provided between the support structure 36a and the first and second stacking members 38a, 40a, the support structure 36a and the first and second stacking members 38a, 40a may have less flexibility between the stacked elements to accommodate insertion of optical fibers 22a, 22b into the fiber alignment grooves 44a-c.

However, in one example, the optical fibers 22a, 22b can be inserted into the stackable multi-fiber alignment device 24a prior to applying the spring force by the biasing component 84 (e.g., the biasing component can be manually actuated by a button or other means after insertion of the fiber optic connectors into their respective ports to apply spring load to the fiber alignment stack). In this way, fiber insertion force requirements can be reduced and less reliance on flexing of the parts is required.

The various examples described above are provided by way of illustration only and should not be construed to limit the scope of the present disclosure. Those skilled in the art will readily recognize various modifications and changes that may be made with respect to the examples and applications illustrated and described herein without departing from the true spirit and scope of the present disclosure.

Claims

CLAIMS What is claimed is:

1. A stackable multi-fiber alignment device for co-axially aligning multiple rows of first and second bare optical fibers to provide an optical coupling between the multiple rows of first and second bare optical fibers, the device comprising: a support structure defining a receptacle for receiving a biasing component; a first stacking member defining a first array of parallel fiber alignment grooves in a first surface thereof, each of the first array of parallel fiber alignment grooves being configured for receiving a first pair of rows of the first and second bare optical fibers; and a second stacking member movable relative to the first stacking member, the second stacking member defining a second array of parallel fiber alignment grooves in a first surface thereof, each of the second array of parallel fiber alignment grooves being configured for receiving a second pair of rows of the first and second bare optical fibers; wherein the support structure and the first and second stacking members are coupled together by a securement arrangement that maintains forcible contact between the first and second surfaces of the first and second stacking members; and wherein, when the support structure and the first and second stacking members are coupled together within a multi-fiber optic adapter, the biasing component is configured to transfer spring load sequentially through the support structure and the first and second stacking members to respectively bias the first and second pairs of rows of the first and second bare optical fibers into the first and second arrays of parallel fiber alignment grooves.

2. The stackable multi -fiber alignment device of claim 1, further comprising a third stacking member through which spring load is transferred and applied to a third pair of rows of the first and second bare optical fibers to bias the first and second bare optical fibers into a third array of parallel fiber alignment grooves.

3. The stackable multi-fiber alignment device of claim 1, wherein the biasing component is a leaf spring.

4. The stackable multi-fiber alignment device of claim 1, wherein the multifiber optic adapter includes a cover that is configured to press down on the biasing component.

5. The stackable multi -fiber alignment device of claim 1, wherein the first and second stacking members include a fiber contact side that opposes an open side of the first and second arrays of parallel fiber alignment grooves and are adapted to engage both the first and second pair of rows of the first and second bare optical fibers when the first and second bare optical fibers are optically coupled together by the multi-fiber optic adapter.

6. The stackable multi -fiber alignment device of claim 1, wherein the support structure includes guides that are received within openings defined in the first and second stacking members to form a nesting interface.

7. The stackable multi -fiber alignment device of claim 1, wherein the first and second stacking members each include a lead-in surface for respectively guiding the first and second pair of rows of the first and second bare optical fibers into the first and second arrays of parallel fiber alignment grooves.

8. The stackable multi-fiber alignment device of claim 7, wherein a cutout region is provided in the first and second stacking members to form raised surfaces at comers of the first and second stacking members.

9. The stackable multi -fiber alignment device of claim 1, wherein the first and second arrays of parallel fiber alignment grooves of the first and second stacking members are separated by precision standoffs.

10. The stackable multi -fiber alignment device of claim 1, wherein the multifiber adapter includes a rigid bed for supporting the stackable multi-fiber alignment device.

11. The stackable multi -fiber alignment device of claim 1 , wherein the first and second arrays of parallel fiber alignment grooves are longitudinally-oriented V-grooves.

12. A bare fiber connection system comprising: first and second bare fiber optic connectors each including: a connector body having a front end and a rear end, the connector body defining a longitudinal axis that extends through the connector body in an orientation that extends from the front end to the rear end of the connector body; and first and second pairs of rows of first and second bare optical fibers extending through the connector body from the rear end to the front end; a multi-fiber adapter defining first and second adapter ports for respectively receiving the first and second bare fiber optic connectors to couple the first and second bare fiber optic connectors together; a stackable multi-fiber alignment device mounted within the multi-fiber adapter for co-axially aligning the first and second pairs of rows of the first and second bare optical fibers to provide an optical coupling therebetween, the stackable multi-fiber alignment device including: a support structure defining a receptacle for receiving a biasing component; a first stacking member defining a first array of parallel fiber alignment grooves in a first surface thereof, each of the first array of parallel fiber alignment grooves being configured for receiving the first pair of rows of the first and second bare optical fibers; and a second stacking member movable relative to the first stacking member, the second stacking member defining a second array of parallel fiber alignment grooves in a first surface thereof, each of the second array of parallel fiber alignment grooves being configured for receiving the second pair of rows of the first and second bare optical fibers; wherein the support structure and the first and second stacking members are coupled together by a securement arrangement that maintains biasing contact therebetween; and wherein, when the support structure and the first and second stacking members are coupled together within the multi-fiber adapter, the biasing component is configured to transfer spring load sequentially through the support structure and the first and second stacking members to respectively bias the first and second pairs of rows of the first and second bare optical fibers into the first and second arrays of parallel fiber alignment grooves.

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13. The bare fiber connection system of claim 12, wherein the biasing component is a leaf spring.

14. The bare fiber connection system of claim 12, wherein the multi-fiber adapter includes a cover that is configured to press down on the biasing component.

15. The bare fiber connection system of claim 12, wherein the support structure includes guides that are received within openings defined in the first and second stacking members to form a nesting interface.

16. The bare fiber connection system of claim 12, wherein the first and second stacking members each include a lead-in surface for respectively guiding the first and second pairs of rows of the first and second bare optical fibers into the first and second arrays of parallel fiber alignment grooves.

17. The bare fiber connection system of claim 16, wherein a cutout region is provided in the first and second stacking members to form raised surfaces at comers of the first and second stacking members.

18. The bare fiber connection system of claim 12, wherein the first and second arrays of parallel fiber alignment grooves of the first and second stacking members are separated by precision standoffs.

19. The bare fiber connection system of claim 12, wherein the multi-fiber adapter includes a rigid bed for supporting the stackable multi-fiber alignment device.

20. The bare fiber connection system of claim 12, wherein the first and second arrays of parallel fiber alignment grooves are longitudinally-oriented V-grooves.

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