WO2011009214A1

WO2011009214A1 - Elastically deformable connector for connecting optical fiber ribbons

Info

Publication number: WO2011009214A1
Application number: PCT/CA2010/001153
Authority: WO
Inventors: Patrick Zivojinovic; Robin Cerutti; Éric WEYNANT
Original assignee: Phasoptx Inc.
Priority date: 2009-07-22
Filing date: 2010-07-21
Publication date: 2011-01-27

Abstract

A ribbon connector mechanically splices optical fibers of a first ribbon to corresponding optical fibers of a second ribbon. The ribbon connector has a connector body made of a highly elastically deformable material such as a shape memory alloy. The connector body has one or more fiber conduits and a central cavity and adjacent deformation slits extending from an outer surface of the connector body into the one or more fiber conduits. The narrow deformation slits enable and then limit deformation of the connector body. The widened central cavity ensures unobstructed access to the fiber conduits when the body is deformed. When force is applied to a first face, a first segment of the conduits expands to allow insertion of the fibers of the first ribbon. When force is applied to a second face, a second segment of the conduits expands to allow insertion of the fibers of the second ribbon.

Description

ELASTICALLY DEFORMABLE CONNECTOR FOR CONNECTING

OPTICAL FIBER RIBBONS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This is the first application filed for the present invention.

TECHNICAL FIELD

[0002] The present invention relates generally to optical fiber connectors for mechanically splicing optical fibers together and, in particular, to connectors for connecting ribbons of optical fibers.

BACKGROUND

[0003] Optical communications systems, which provide the backbone of most modern long-haul telecommunications networks, use fiber optic cables to carry the optical signals from one node to another. Splicing optical fibers remains a technical problem for which a fully satisfactory solution has yet to have been devised.

[0004] Two general optical fiber splicing techniques are known in the art, arc fusion splicing and mechanical splicing. Arc fusion splicing is accomplished by fusing the ends of optical fibers together with a spark generated by electrodes. This technique tends to be intricate and time-consuming to utilize. Mechanical splicing is a much quicker technique but it has a propensity to incur high optical losses (insertion losses) across the connection or coupling due to the bonded joint. Mechanically splicing fibers typically requires that the fibers be aligned and held together using a precision sleeve and gel adhesive having a carefully selected index of refraction that minimizes Fresnel reflection across the splice. Nonetheless, these mechanical splices typically have higher optical losses and are less robust than fusion splices, even if a protective enclosure is used.

[0005] The use of a glue or bonding agent to bond the mechanical splices together is problematic because the bond may come undone, especially in the presence of thermal extremes (i.e. may melt or loosen in extreme heat or become brittle in extreme cold) . For many applications, therefore, a bonded connection is unsatisfactory. Furthermore, a bonded connection cannot be rotated inside the connector, i.e. one fiber cannot be rotated relative to the other fiber. For applications where the polarization of light matters, a bonded mechanical splice can be inflexible. Moreover, another significant disadvantage of bonded couplings is that they cannot be reused.

[0006] Applicant has developed a number of innovative mechanical connectors for splicing optical fibers. See, e.g., WO 2004/015473 published Feb. 19, 2004 and WO 2005/040876 published May 6, 2005 as well as U.S. Patent 7,490,995. These fiber connectors can be made of shape memory alloy or other highly elastic materials. These connectors, however, are not specifically designed to connect a ribbon of fibers to another ribbon of fibers. Thus, there remains a need for a connector capable of easily and efficiently mechanically splicing the optical fibers of one ribbon to the corresponding optical fibers of another ribbon.

SUMMARY

[0007] In broad terms, the present invention provides a novel elastically deformable ribbon connector for splicing optical fibers of a first ribbon to the corresponding optical fibers of a second ribbon. This invention also provides an innovative method for connecting optical fiber ribbons to one another. As will be elaborated below, these various aspects

— 9— of the invention enable the optical fibers of one ribbon to be spliced easily and efficiently to the corresponding optical fibers of another ribbon while also minimizing signal losses across the resulting splices. The purely mechanical splices provided by this connector do not require any bonding or adhesives. Not only are the splices much more impervious to thermal degradation than bonded connections, but the connector itself is also entirely reusable.

[0008] Accordingly, one main aspect of the present invention is an elastically deformable connector for mechanically splicing optical fibers of a first ribbon to corresponding optical fibers of a second ribbon. The connector comprises a connector body made of a highly elastic material that deforms elastically when a force is applied to an outer surface of the connector body. The connector includes a plurality of inline fiber conduits extending through the connector body from a first face of the connector body to a second face of the connector body, the conduits being dimensioned to receive the optical fibers when expanded and to grip the optical fibers when the conduits contract to an original shape. The connector has first and second fiber slots each extending inwardly into the connector body from the first and second faces, respectively, in a plane defined by the inline fiber conduits, the first and second fiber slots enabling expansion of respective segments of the inline fiber conduits. The connector also includes a central cavity extending into the fiber conduits and adjacent deformation slits formed in the connector body. The deformation slits assist and then limit deformation of the connector body when force is exerted on the connector body. The central cavity enables the conduits to open sufficiently for insertion of the fibers therein.

[0009] Another main aspect of the present invention is a method of splicing optical fibers of a first ribbon to corresponding optical fibers of a second ribbon. The method entails first providing an elastically deformable connector having a connector body made of a highly elastic material, and then aligning the fibers of the first ribbon with a plurality of inline fiber conduits extending through the connector body from a first face of the connector body to a second face of the connector body. The method then involves exerting a force on the first face of the connector body to expand a first segment of the fiber conduits adjoining the first face. The connector body has a central cavity and adjacent deformation slits that assist and then limit deformation of the connector body while the central cavity ensures that the conduits open sufficiently to permit insertion of the fibers therein. After exerting the force to deform the connector body, the method then entails inserting the fibers of the first ribbon into the first segment of the fiber conduits via the first face and then releasing the force on the first face of the connector body to cause the first segment of the fiber conduits to contract onto the fibers of the first ribbon. The steps are then repeated for the second fiber. In other words, the method then entails aligning the fibers of the second ribbon with the plurality of inline fiber conduits, exerting a force on the second face of the connector body to expand a second segment of the fiber conduits, inserting the fibers of the second ribbon into the second segment of the fiber conduits via the second face, and releasing the force on the second face of the connector body to cause the second segment of the fiber conduits to contract onto the fibers of the second ribbon. Accordingly, this method splices the fibers of the second ribbon to the corresponding fibers of the first ribbon.

[0010] Yet another main aspect of the present invention is an elastically deformable connector for mechanically splicing a first optical fiber to a second optical fiber. The connector has a connector body made of a highly elastic material. The connector has a first segment of fiber conduit extending into the connector body from a first face of the connector body and a second segment of fiber conduit extending into the connector body from a second face of the connector body. The second segment of fiber conduit is aligned with the first segment of fiber conduit. The connector also has a first fiber slot extending through the first segment of fiber conduit and into the connector body from the first face and a second fiber slot extending through the second segment of fiber conduit and into the connector body from the second face. A central cavity and adjacent deformation slits are formed in the connector body. This central cavity extends from an outer surface of the connector body into the first and second segments of fiber conduit. The adjacent deformation slits assist and then limit deformation of the connector body when force is applied to the connector body while the central cavity ensures that the conduits provide unobstructed access for the fibers to be inserted therein. Accordingly, the first and second segments of fiber slot may be expanded independently when force is exerted on the first and second faces, respectively.

[0011] Yet a further main aspect of the present invention is a method of splicing a first optical fiber to a second optical fiber. The method involves providing an elastically deformable connector having a connector body made of a highly elastic material. The first optical fiber is aligned with a first segment of a fiber conduit extending into the connector body from a first face. Force is then exerted on the first face to cause deformation of the connector body. The connector body has a central cavity that extends into the fiber conduit and adjacent deformation slits that assist and limit the deformation of the connector body to thereby enable expansion of the first segment of the fiber conduit. The first fiber is then inserted into the first segment of the fiber conduit and the force on the first face released to cause the first segment of the fiber conduit to contract onto the first fiber. The steps are then repeated for the second fiber, namely aligning the second optical fiber with the second segment of the fiber conduit, exerting a force on the second face to expand the second segment of the fiber conduit, inserting the second fiber into the second segment of the fiber conduit, and releasing the force on the second face to cause the second segment of the fiber conduit to contract onto the second fiber.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0001] FIG. 1 is a perspective view of a 12-fiber ribbon in which the coatings have been partially removed to reveal the fiber ends;

[0002] FIGS. 2A and 2B are semi-transparent and solid isometric views of a ribbon connector in accordance with an embodiment of the present invention;

[0003] FIG. 3A is a solid isometric view of a sliced-off portion of the connector of FIGS. 2A and 2B showing interior details of the fiber conduits;

[0004] FIG. 3B is a side view of the sliced-off portion of the connector of FIG. 3A;

[0005] FIG. 3C is an oblique view of the connector of FIG. 3A; [0006] FIG. 4A is a side view showing differently profiled sections of the fiber conduits;

[0007] FIG. 4B is an isometric view of a sliced-off portion of the connector showing funnel-shaped (i.e. conically flared) entries for the fiber conduits;

[0008] FIG. 4C is a side view of a different hole profiles for the fiber conduit;

[0009] FIG. 5A is a side view of a sliced portion of the connector;

[0010] FIG. 5B is a semi-transparent isometric view of the sliced portion of the connector;

[0011] FIG. 5C is a solid isometric view of the sliced portion of the connector;

[0012] FIG. 5D is an oblique view of the sliced portion of the connector;

[0013] FIG. 6A is a side view of another embodiment of a connector having a full cavity extending through the entire connector body;

[0014] FIG. 6B is an isometric view of the connector of FIG. 6A;

[0015] FIG. 6C is a semi-transparent isometric view of the connector of FIG. 6A;

[0016] FIG. 6D is a semi-transparent top view of the connector of FIG. 6A;

[0017] FIG. 6E is an oblique view of the connector of FIG. 6A; [0018] FIG. 7A is a side view of the ribbon connector in accordance with one embodiment of the invention;

[0019] FIG. 7B is a top view of the ribbon connector in accordance with one embodiment of the invention;

[0020] FIG. 7C is a frontal view of the ribbon connector in accordance with one embodiment of the invention;

[0021] FIG. 8A is a semi-transparent side view of the ribbon connector in accordance with one embodiment of the invention;

[0022] FIG. 8B is a semi-transparent top view of the ribbon connector in accordance with one embodiment of the invention;

[0023] FIG. 8C is a semi-transparent frontal view of the ribbon connector in accordance with one embodiment of the invention;

[0024] FIGS. 9A and 9B are solid and semi-transparent isometric views of a single-fiber connector in accordance with another embodiment of the invention;

[0025] FIG. 10 depicts installation of a first ribbon into one embodiment of the connector;

[0026] FIG. 11 depicts installation of a second ribbon into the connector FIG. 10; and

[0027] FIGS. 12 is an oblique view of the connector with a first ribbon inserted therein.

[0028] It will be noted that throughout the appended drawings, like features are identified by like reference numerals. It should furthermore be noted that the drawings are not necessarily to scale. DETAILED DESCRIPTION

[0029] In general, and by way of introduction, the present invention provides a novel ribbon-to-ribbon connector ("ribbon connector") and a novel method of splicing optical fibers of one ribbon to corresponding optical fibers of another ribbon. By way of overview, and as will be elaborated below, the ribbon connector has a connector body made of a highly elastic material such as, for example, a shape memory alloy that deforms when a force (or pressure) is exerted on an outer surface of the connector body. When an external force or pressure is exerted on the outer surface of the connector body, the body deforms to expand one or more fiber conduits (fiber-receiving openings) that, when the force or pressure is relieved, contract to grip and hold the fiber (s) in place. Different variants of this ribbon connector can be used to connect not only standard ribbons having twelve (12) (such as the ribbon shown in FIG. 1) or twenty-four (24) fibers but also a ribbon having any arbitrary number of fibers, including a "ribbon" consisting of a single fiber. Regardless of the number of fibers in the ribbon, the connector can be designed to grip the coating, the cladding or both. Furthermore, it should be understood that embodiments of the invention can be adapted to connect fibers of different diameters.

[0030] For example, a ribbon 2 is shown in FIG. 1 as having coating 6 on the fibers 4 over all but a portion of the fibers. Each coating is connected to the next coating (at common edges 8) to form the ribbon 2 as shown in FIG. 1. As will be appreciated, the connectors described herein can be used to connect not just the ribbon shown in FIG. 1 but any other type of ribbon (with suitable modifications being made to the connector to accommodate the physical shape of the ribbon, the number of fibers and the amount of coating being removed) . [0031] This novel connector and ribbon-connecting technique therefore enable easy and efficient splicing of optical fibers of one ribbon with corresponding fibers of another ribbon.

[0032] Specific embodiments and implementations of the present invention will now be described below, by way of example, with reference to the attached drawings.

[0033] FIG. 2A and 2B depict an elastically deformable ribbon connector 10 in accordance with one embodiment of the present invention. The ribbon connector is used to mechanically splice optical fibers of a first ribbon to corresponding optical fibers of a second ribbon, thereby connecting the first ribbon to the second ribbon. This ribbon connector 10 comprises a connector body 12 made of a highly elastic material that deforms elastically when a force is applied to the connector body. The connector body may, for example, be made of a shape memory alloy, e.g. an alloy of copper and aluminum, which provides extremely high elasticity (i.e. super-elasticity or pseudo-elasticity) . As will be elaborated below, other shape memory alloys or highly elastic materials may also be used. Shape memory materials provide high levels of elasticity, while at the same time provide the desired levels of rigidity, durability and thermal properties that make this material an excellent candidate for mechanically coupling optical fibers .

[0034] The connector body includes an opening 14 disposed generally orthogonally to the conduits. The opening 14 comprises both a central cavity 14A in an interior portion of the connector body and adjacent deformation slits 14B. The deformation slits 14B enable limited deformation of the connector body when the force is applied, i.e. allows the connector body to deform over a limited range before substantially blocking further deformation. The central cavity 14A is formed in the connector body and extends into the fiber conduits 16 to provide proper clearance internally when the body is deformed to thereby enable unobstructed insertion of the fibers into the respective conduits. Because of the cavity 14A, the fiber conduits (and thus the fiber splices) are therefore accessible, enabling addition of gel, cleaning of the splices, and other functions, which will be elaborated below under the heading entitled Advantages.

[0035] In the embodiment depicted in FIG. 2A and 2B, the connector body 12 also has a plurality of inline fiber conduits 16 (i.e. a series of side-by-side fiber-receiving openings or fiber-splicing channels) dimensioned and otherwise adapted for receiving and splicing respective optical fibers of each of the ribbons to be connected together. The inline fiber conduits 16 extend through the connector body 12 from a first face 18 of the connector body to a second face 20 of the connector body. These conduits are dimensioned to receive the optical fibers when expanded and to grip the optical fibers when the conduits contract to an original shape.

[0036] In addition, the connector body has first and second fiber slots 22, 24 each extending inwardly into the connector body from the first and second faces, respectively, in a plane defined by the inline fiber conduits, the first and second fiber slots 22, 24 enabling expansion of respective segments 16A, 16B of the inline fiber conduits 16.

[0037] The fiber conduits are divided into separately actuatable segments by the central cavity 14A. The first and second segments 16A and 16B (of the fiber conduits are best shown in FIG. 3A and 3B. As shown in these latter figures, the first segment 16A of the fiber conduits extends inwardly from the first face 18 while the second segment 16B of the fiber conduits extends inwardly from the second face 20. In other words, in this particular connector, the first and second segments extend inwardly toward each other. These segments extend into the central cavity which allows each of these segments to be separately actuated, i.e. expanded and contracted independently of the other segment. Accordingly, the first and second segments can be expanded and contracted sequentially (serially) to enable insertion of the fibers of the first ribbon and then insertion of the fibers of the second ribbon or vice versa. FIG. 3A and FIG. 3B show the deformed connector. FIG. 3C is a tilted side view of the connector when deformed. In each of these figures, the fiber conduit has a first section of diameter dl and a second section of diameter d2. In other words, each fiber conduit comprises a first section of diameter dl for gripping a respective fiber and a second section of diameter d2 for gripping a coated portion of the fiber.

[0038] As depicted in FIG. 3B, the central cavity 14A and adjacent deformation slits 14B extend substantially orthogonally to a force vector of the force F applied to the connector body. The shape and size of these deformation slits 14C determines the amount of flexure in the body, i.e. not only how easily it deforms but also how far it can deform until one side of the gap abuts the other side of the gap. In the embodiments illustrated, the central cavity 14A has a wide oblong portion that spans the inline fiber conduits. This wide oblong portion ensures that when the body deforms, its rotation does not impede insertion of the optical fibers of the ribbon. Were the cavity merely an extension of the adjacent narrow deformation slits 14B, rotation of the body under the applied force would block the fibers from being slid into the conduits. Thus, the widening of the cavity 14A over a region spanning the inline fiber conduits ensures that the conduits remain unobstructed during deformation of the body. In other words, as best illustrated in FIGS. 3B, the connector deforms elastically under pressure due to the deformation slits. The geometry and location of the central cavity- enables the fiber conduits to expand (widen) beyond the fiber diameter of the fibers of the ribbon to enable unobstructed insertion of the ribbon into the connector. In other words, the central cavity ensures that there is unobstructed access to the fiber conduits when the connector body is deformed. Were the central cavity no wider than the narrow slits, the fiber conduits would be partially obstructed due to the deformation of the connector body. The widened central cavity ensures that deformation of the body does not block the fiber conduits .

[0039] In one embodiment of the invention, the central cavity 14A comprises a wide oblong portion extending from an outer surface of the connector body into the inline fiber conduits, thereby dividing the inline fiber conduits into a first segment of fiber conduit and a second segment of fiber conduit, the first and second segments of fiber conduits being independently expandable. The narrow deformation slits 14B extend from lateral edges 14C of the wide oblong portion of the central cavity 14A to respective lateral surfaces 14D of the connector body.

[0040] In the embodiment depicted in FIG. 3A, the major axis of the wide oblong portion is perpendicular to the fiber conduits while the minor axis is parallel to the conduits.

[0041] APPLICATION OF FORCE OR PRESSURE

[0042] In the illustrations, the force is shown as acting orthogonally to a surface of the connector body (and also orthogonally to the deformation slits and central cavity) . This is not essential. In other words, in other embodiments of the present invention, the applied force vector need not act perpendicularly to the surface of the connector body. Likewise, the force vector is not necessarily perpendicular to the cavity and adjacent deformation slits. The force may be applied obliquely on the surface of the connector. In other words, the force may act obliquely relative to the deformation slits and central cavity.

[0043] Force or pressure can be exerted manually, e.g. by finger or thumb, or by using a tool or implement, or by driving an actuator such as a piezoelectric element by exploiting the reverse piezoelectric effect (inducing strain by application of an electric field) , or any suitable combination thereof.

[0044] FABRICATION

[0045] Each of the fiber conduits of this ribbon connector is preferably machined or cut in a single operation. In other words, the fiber conduits are machined or cut from one face through to the other face rather than machining from one side and then machining from the other side, which can result in misalignment. Once the fiber conduits are machined, the central cavity can be machined.

[0046] ADVANTAGES OF CENTRAL CAVITY

[0047] The ribbon-connecting technology described and illustrated in this application provides a number of significant advantages and benefits which are a consequence of having the central cavity providing access to the fiber connections (splices) . Some of the key advantages are:

[0048] 1) The access to the splices through the central cavity enables index-matching gel to be added. [0049] 2) The access to the splices enables one to see the connection.

[0050] 3) The access also enables the connections to be cleaned (e.g. using a pressurized air jet).

[0051] 4) The access also enables the ribbon connector to be used for sensor applications. For example, if the corresponding optical fibers are left spaced apart with an air gap between ends of the fibers, light passing from one fiber to another fiber can be used to detect or sense the presence of gases/liquid that alter the light properties as the light passes through the gap.

[0052] 5) The access provides direct air cooling or enables direct liquid cooling of the connections rather than cooling the connection indirectly by cooling the connector.

[0053] CLEAVING

[0054] As is known in the art, the fiber ends are cleaved at an oblique angle to minimize reflection at the interface of the adjoining fiber ends. The presence of the ribbon ensures that the angle of cleavage is consistent across all the fibers in the ribbon. Furthermore, the ribbon maintains the cleaving angle for all the fibers so that these can be easily and efficiently spliced to complementarily cleaved fibers on another ribbon.

[0055] As will be appreciated, the novel ribbon connector and novel splicing technique enabled by this novel ribbon connector can be used in a variety of ways to facilitate splicing of the optical fibers of one ribbon with the corresponding optical fibers on another ribbon.

[0056] With these novel ribbon connectors, no glue is required to hold the fibers inside the connectors, thus making the splices temperature resistant. In some cases, the connection also does not require adhesive gel at the joint. The absence of adhesive also means that the connector can be reused.

[0057] HIGHLY ELASTIC MATERIAL

[0058] The connector body should be made of a highly elastic material, e.g. a shape memory material (SMM) such as a shape memory alloy (SMA) or other such material that is capable of being easily deformed and whose elasticity is high enough to return to its original, undeformed shape when the force or pressure is released from the connector body In main implementations of this technology, a shape-memory alloy is used for the connector body since shape memory alloys exhibit unusually high elasticity and are thus perfectly suited for this application. A copper-aluminum shape memory alloy has been found to provide excellent results. However, as will be appreciated by those of ordinary skill in the art who have had the benefit of reading this disclosure, other functionally equivalent shape-memory alloys can also be used. Indeed, any highly elastic material that has an elasticity comparable to the copper-aluminum alloy could be utilized to provide similar results. The optical fiber connector device of the present invention may, for example, be made from a polymeric material such as isostatic polybutene, shape ceramics such as zirconium with some addition of Cerium, Beryllium or Molybdenum, copper alloys including binary and ternary alloys, such as Copper - Aluminum alloys, Copper - Zinc alloys, Copper - Aluminum - Beryllium alloys, Copper - Aluminum - Zinc alloys and Copper - Aluminum - Nickel alloys, Nickel alloys such as Nickel - Titanium alloys and Nickel - Titanium - Cobalt alloys, Iron alloys such as Iron - Manganese alloys, Iron - Manganese - Silicon alloys, Iron - Chromium - Manganese alloys and Iron - Chromium - Silicon alloys, Aluminum alloys, and high elasticity composites which may optionally have metallic or polymeric reinforcement.

[0059] FIBER CONDUIT SECTIONS

[0060] Δs depicted in FIG. 4A, 4B and 4C, the fiber conduits may be manufactured with different profiles or sections. For example, each fiber conduit may comprise a first section of diameter dl for gripping a respective fiber and a second section of diameter d2 for gripping a coated portion of the fiber. Alternatively, each fiber conduit may comprise a first section of diameter dl for gripping a respective fiber, a second section of diameter d2 for gripping a coated portion of the fiber and a third flared section to facilitate insertion of the fiber. Alternatively, each fiber conduit may simply be flared (funnel-shaped) to facilitate insertion of the fiber.

[0061] OTHER EMBODIMENTS AND VARIANTS

[0062] In another embodiment of the invention, the wide oblong portion 14A extends from the outer surface of the connector body to an opposite outer surface of the connector body, i.e. right through the body from the top to the bottom, as shown in FIGS. 6A-6E as opposed to extending only into the fiber conduits as shown in FIGS. 5A-5D.

[0063] FIGS. 7A-7C and FIGS. 8A-8C show a ribbon connector designed for ribbons having twelve (12) fibers. As will be appreciated, the connector may be designed to receive twenty- four (24) fibers or any other number of fibers, including only a single fiber. In one embodiment, the connector can be designed to connect fibers of a first diameter with fibers of a second (different) diameter provided that the respective ribbons have spaced the differently-sized fibers to align with one another. In other words, the inline fiber conduits may have segments of different diameter. Thus, for example, it might be possible to connect fibers having a diameter of 125μm with fibers having a diameter of 250μm, again assuming that the spacing between fibers within their respective ribbons allows the fibers to be aligned with one another. Not only can the segments of the fiber conduits be sized differently to connect fibers of different diameters, but an embodiment of the connector may be designed to connect ribbons wherein each ribbon contains differently sized fibers. In other words, each of the ribbons may contain fibers of different diameters, i.e. a mix of differently sized fibers. A connector can thus be manufactured to accommodate any predetermined arrangement or combination of differently sized fibers by providing suitably sized and spaced apart conduits.

[0064] FIG. 9A and FIG. 9B show a single-fiber connector. In this embodiment, the oblong portion of the central cavity is oriented such that its major axis is parallel to the fiber conduit and its minor axis is parallel to the narrow slits. Accordingly, an elastically deformable connector for mechanically splicing a first optical fiber to a second optical fiber includes a connector body made of a highly elastic material (e.g. a shape memory alloy) . A first segment of fiber conduit extends into the connector body from a first face of the connector body. A second segment of fiber conduit extends into the connector body from a second face of the connector body, the second segment of fiber conduit being aligned with the first segment of fiber conduit. A first fiber slot extends through the first segment of fiber conduit and into the connector body from the first face. A second fiber slot extends through the second segment of fiber conduit and into the connector body from the second face. A central cavity is formed in the connector body and extends from an outer surface of the connector body into the first and second segments of fiber conduit. The central cavity is preferably a wide oblong portion. A pair of adjacent narrow deformation slits assists and then limits deformation of the connector body when force is applied to the connector body so that the first and second segments of fiber slot may be expanded independently when force is exerted on the first and second faces, respectively. The central cavity ensures that there is sufficient internal clearance when the body is deformed to permit unobstructed insertion of the fibers into the corresponding conduits. In embodiments of this single fiber connector, the conduits may be differently sized to accommodate and connect together two fibers of different diameter .

[0065] METHOD

[0066] FIG. 10 and FIG. 11 depict a novel method of connecting ribbons using the novel ribbon connector. FIG. 10 shows insertion of a first ribbon while FIG. 11 shows subsequent insertion of a second ribbon into the same connector. The novel method of splicing a first optical fiber to a second optical fiber comprises (1) providing an elastically deformable connector having a connector body made of a highly elastic material; (2) aligning the first optical fiber with a first segment of a fiber conduit extending into the connector body from a first face; (3) exerting a force on the first face to cause deformation of the connector body, the connector body having a central cavity that extends into the fiber conduit and adjacent deformation slits that assist and limit the deformation of the connector body to thereby enable expansion of the first segment of the fiber conduit; (4) inserting the first fiber into the first segment of the fiber conduit; (5) releasing the force on the first face to cause the first segment of the fiber conduit to contract onto the first fiber; (6) aligning the second optical fiber with the second segment of the fiber conduit; (7) exerting a force on the second face to expand the second segment of the fiber conduit; (8) inserting the second fiber into the second segment of the fiber conduit; and (9) releasing the force on the second face to cause the second segment of the fiber conduit to contract onto the second fiber.

[0067] From the foregoing, it should now be evident that this novel ribbon connector provides a number of significant advantages over the prior art. For example, this novel ribbon connector is easy to use, thus simplifying the task of connecting optical fiber ribbons together. The optical losses over this connector are low. Furthermore, since no bond or adhesive is required, the ribbon-to-ribbon connector is temperature resistant. Therefore, this connector may be used in a variety of temperature-sensitive applications such as, for example, aerospace applications where temperature cycling is extreme or laser applications where the heat of the laser is extreme. The absence of adhesive or bonding material enables the connector to be reused. The design of this connector is furthermore amenable to miniaturization.

[0068] While the primary application of this technology is connecting ribbons of optical fiber, it should be appreciated that it can also be adapted to connect one or more tubes, micro-fluidic piping, etc. where two tubular or cylindrical structures are to be joined, spliced or connected together.

[0069] The present invention has been described in terms of specific embodiments, examples, implementations and configurations which are intended to be exemplary or illustrative only. Other variants, modifications, refinements and applications of this innovative technology will become readily apparent to those of ordinary skill in the art who have had the benefit of reading this disclosure. Such variants, modifications, refinements and applications fall within the ambit and scope of the present invention. Accordingly, the scope of the exclusive right sought by the Applicant for the present invention is intended to be limited solely by the appended claims and their legal equivalents.

Claims

CLAIMS :

1. An elastically deformable connector for mechanically splicing optical fibers of a first ribbon to corresponding optical fibers of a second ribbon, the connector comprising:

a connector body made of a highly elastic material that deforms elastically when a force is applied to an outer surface of the connector body;

a plurality of inline fiber conduits extending through the connector body from a first face of the connector body to a second face of the connector body, the conduits being dimensioned to receive the optical fibers when expanded and to grip the optical fibers when the conduits contract to an original shape;

first and second fiber slots each extending inwardly into the connector body from the first and second faces, respectively, in a plane defined by the inline fiber conduits, the first and second fiber slots enabling expansion of respective segments of the inline fiber conduits; and

a central cavity and adjacent deformation slits formed in the connector body, the deformation slits assisting and then limiting deformation of the connector body when force is exerted on the connector body while the central cavity ensures unobstructed access for insertion of the fibers into respective conduits .

2. The connector as claimed in claim 1 wherein the central cavity and adjacent deformation slits extend substantially orthogonally to a force vector of the force applied to the connector body.

3. The connector as claimed in claim 2 wherein the central cavity and adjacent deformation slits comprise:

a wide oblong portion extending from an outer surface of the connector body into the inline fiber conduits, thereby dividing the inline fiber conduits into a first segment of fiber conduit and a second segment of fiber conduit, the first and second segments of fiber conduits being independently expandable; and a pair of narrow deformation slits extending from lateral edges of the wide oblong portion to respective lateral surfaces of the connector body.

4. The connector as claimed in claim 3 wherein the wide oblong portion extends from the outer surface of the connector body to an opposite outer surface of the connector body.

5. The connector as claimed in claim 1 wherein each fiber conduit comprises a first section of diameter dl for gripping a respective fiber and a second section of diameter d2 for gripping a coated portion of the fiber.

6. The connector as claimed in claim 1 wherein each fiber conduit comprises a first section of diameter dl for gripping a respective fiber, a second section of diameter d2 for gripping a coated portion of the fiber and a third flared section to facilitate insertion of the fiber.

7. The connector as claimed in claim 1 wherein each fiber conduit is flared to facilitate insertion of the fiber.

8. The connector as claimed in claim 1 wherein the connector body is made of a shape memory alloy.

9. The connector as claimed in claim 3 wherein a major axis of the oblong portion is parallel to the slits while a minor axis of the oblong portion is parallel to the inline fiber conduits.

10. A method of splicing optical fibers of a first ribbon to corresponding optical fibers of a second ribbon, the method comprising:

providing an elastically deformable connector having a connector body made of a highly elastic material; aligning the fibers of the first ribbon with a plurality of inline fiber conduits extending through the connector body from a first face of the connector body to a second face of the connector body; exerting a force on the first face of the connector body to expand a first segment of the fiber conduits adjoining the first face, the connector body having a central cavity and adjacent deformation slits that assist and then limit deformation of the connector body while the central cavity ensures unobstructed access to the fiber conduits when the body is deformed;

inserting the fibers of the first ribbon into the first segment of the fiber conduits via the first face; releasing the force on the first face of the connector body to cause the first segment of the fiber conduits to contract onto the fibers of the first ribbon; L WO aligning the fibers of the second ribbon with the plurality of inline fiber conduits;

exerting a force on the second face of the connector body to expand a second segment of the fiber conduits ;

inserting the fibers of the second ribbon into the second segment of the fiber conduits via the second face; and

releasing the force on the second face of the connector body to cause the second segment of the fiber conduits to contract onto the fibers of the second ribbon, thereby splicing the fibers of the second ribbon to the corresponding fibers of the first ribbon .

11. The method as claimed in claim 10 further comprising adding index-matching gel to ends of the fibers via the central cavity.

12. The method as claimed in claim 10 further comprising cleaning the fibers via the central cavity.

13. The method as claimed in claim 10 further comprising cooling the fibers via the central cavity.

14. The method as claimed in claim 10 wherein the fibers of the first ribbon have a diameter dl different from a diameter d2 of the fibers of the second ribbon.

15. An elastically deformable connector for mechanically splicing a first optical fiber to a second optical fiber, the connector comprising:

a connector body made of a highly elastic material; a first segment of fiber conduit extending into the connector body from a first face of the connector body;

a second segment of fiber conduit extending into the connector body from a second face of the connector body, the second segment of fiber conduit being aligned with the first segment of fiber conduit;

a first fiber slot extending through the first segment of fiber conduit and into the connector body from the first face;

a second fiber slot extending through the second segment of fiber conduit and into the connector body from the second face; and

a central cavity and adjacent deformation slits formed in the connector body and extending from an outer surface of the connector body into the first and second segments of fiber conduit, the deformation slits assisting and then limiting deformation of the connector body when force is applied to the connector body so that the first and second segments of fiber slot may be expanded independently when force is exerted on the first and second faces, respectively, the central cavity ensuring unobstructed access to the conduits when the body is deformed.

16. The connector as claimed in claim 15 wherein the central cavity and adjacent deformation slits comprise:

a wide oblong portion extending from an outer surface of the connector body into the first and second segments of fiber conduit; and a pair of narrow slits extending from lateral edges of the wide oblong portion to respective lateral surfaces of the connector body.

17. The connector as claimed in claim 16 wherein the wide oblong portion extends from the outer surface of the connector body to an opposite outer surface of the connector body.

18. The connector as claimed in claim 15 wherein each fiber conduit comprises a first section of diameter dl for gripping a respective fiber and a second section of diameter d2 for gripping a coated portion of the fiber.

19. The connector as claimed in claim 15 wherein each fiber conduit comprises a first section of diameter dl for gripping a respective fiber, a second section of diameter d2 for gripping a coated portion of the fiber and a third flared section to facilitate insertion of the fiber.

20. The connector as claimed in claim 15 wherein each fiber conduit is flared to facilitate insertion of the fiber.

21. The connector as claimed in claim 15 wherein the connector body is made of a shape memory alloy.

22. The connector as claimed in claim 16 wherein a major axis of the oblong portion is parallel to the first and second segments of fiber conduit while a minor axis of the oblong portion is parallel to the narrow slits.

23. A method of splicing a first optical fiber to a second optical fiber, the method comprising: providing an elastically deformable connector having a connector body made of a highly elastic material; aligning the first optical fiber with a first segment of a fiber conduit extending into the connector body from a first face;

exerting a force on the first face to cause deformation of the connector body, the connector body having a central cavity and adjacent deformation slits that assist and limit the deformation of the connector body to thereby enable expansion of the first segment of the fiber conduit, the central cavity ensuring unobstructed access to the fiber conduits when the connector body is deformed;

inserting the first fiber into the first segment of the fiber conduit;

releasing the force on the first face to cause the first segment of the fiber conduit to contract onto the first fiber;

aligning the second optical fiber with the second segment of the fiber conduit;

exerting a force on the second face to expand the second segment of the fiber conduit;

inserting the second fiber into the second segment of the fiber conduit; and

releasing the force on the second face to cause the second segment of the fiber conduit to contract onto the second fiber.

24. The method as claimed in claim 23 wherein inserting the second fiber comprises inserting the second fiber until it abuts the first fiber to thereby mechanically splice the fibers .

25. The method as claimed in claim 23 wherein inserting the second fiber comprises inserting the second fiber without abutting the first fiber to thereby leave an air gap between the first and second fibers.

26. The method as claimed in claim 24 further comprising cleaving the first and second fibers.

27. The method as claimed in claim 26 further comprising adding index-matching gel to ends of the fibers via the central cavity.

28. The method as claimed in claim 23 further comprising cleaning the fibers via the central cavity.

29. The method as claimed in claim 23 further comprising cooling the fibers via the central cavity.

30. The method as claimed in claim 23 wherein the fibers of the first ribbon have a diameter dl different from a diameter d2 of the fibers of the second ribbon.