Multi-fiber hardened fiber optic connection systems

Abstract

The present disclosure relates to small form-factor fiber optic connectors having hardened configurations. The fiber optic connectors can be multi-fiber optical connectors. The fiber optic connectors can be convertible into different optical connection form factors to enhance backward compatibility. The hardened multi-fiber optical connectors can be receive by fiber optic adapters.

Description

Attorney Docket No. 02316.8909WOU1 / 7478WOW1MULTI-FIBER HARDENED FIBER OPTIC CONNECTION SYSTEMSCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is being filed on September 9, 2025, as a PCT International Patent application and claims the benefit of U.S. Provisional Application Serial No. 63 / 692,360 filed September 9, 2024, and claims the benefit of U.S. Provisional Application Serial No. 63 / 752,369 filed January 31, 2025, the entire disclosures of which are incorporated by reference herein.TECHNICAL FIELD

[0002] The present disclosure relates generally to fiber optic connection systems. More particularly, the present disclosure relates to fiber optic connection systems that are hardened to be suitable for outside environmental use.BACKGROUND

[0003] 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.

[0004] 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 and the ferrules are forced proximally relative totheir 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, alignment between two fiber optic connectors is provided through the use of an intermediate fiber optic adapter.

[0005] Ruggedized (i.e., hardened) fiber optic connection systems include fiber optic connectors and fiber optic adapters suitable for outside environmental use. These types of systems are typically environmentally sealed and include robust fastening arrangements suitable for withstanding relatively large pull loading and side loading. Example ruggedized fiber optic connection systems are disclosed by US. Patent Nos. 7,467,896; 7,744,288; 8,556,520 and 9,442,257. Ruggedized connection systems including a splice-on connectors are disclosed by US 11,119,277 and US 9,442,257.

[0006] It will be appreciated that a number of different types of ruggedized fiber optic connectors are available for outside environmental use. PCT International Publication No. WO2015 / 028433 discloses a system for making fiber optic connectors in which a number of different ruggedized outer assemblies having different formfactors or configurations can be selectively mounted on a pre-terminated cable such that the pre-terminated cable can be customized to be compatible with a particular style or type of fiber optic connector or fiber optic adapter. Other systems are disclosed by PCT International Publication Nos. W02021 / 041305 and WO2020 / 236512; US Patent Nos. 11,822,142 and 11,921,329; and US Patent Publication No. US 20223 / 0161111.SUMMARY

[0007] Aspects of the present disclosure relate to a multi-fiber optical connector having a small form factor. In certain examples, the muti-fiber optical connector is hardened (i.e., ruggedized). In certain examples, the multi-fiber connector can carry an elastomeric seal. In certain examples, the multi-fiber optical connector is a hardened multi-fiber optical connector that is convertible to a standard MPO (Multi-fiber Push On) optical connector form factor that can be received in a standard MPO fiber-optic adapter. In certain examples, the multi-fiber optical connector is convertible to otherhardened multi-fiber optical connector form factors to enhance backward compatibility. Other aspects of the present disclosure relate to fiber optic adapters for receiving hardened multi-fiber optical connectors in accordance with the principles of the present disclosure.

[0008] A variety of additional inventive aspects will be set forth in the description that follows. The inventive 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

[0009] FIG. 1 is a perspective view of a multi-fiber optical connector in accordance with the principles of the present disclosure;

[0010] FIG. 2 is an exploded view of the multi-fiber optical connector of FIG. 1;

[0011] FIG. 3 is a perspective view depicting an optical connection end of a multifiber ferrule of the multi-fiber optical connector of FIG. 2;

[0012] FIG. 4 is a perspective view depicting a fiber entrance and of the multifiber ferrule of FIG. 3;

[0013] FIG. 5 is an end view of the optical connection and of the multi-fiber ferrule of FIG. 3;

[0014] FIG. 6 is a cross-sectional view horizontally bisecting the multi-fiber ferrule of FIG. 3;

[0015] FIG. 7 is a perspective view depicting a main body of a front body of a connector body of the multi-fiber optical connector of FIG. 2, the main body is viewed from a perspective showing a front end of the main body;

[0016] FIG. 8 is another perspective view depicting the front end of the main body of FIG. 7;

[0017] FIG. 9 is a further perspective view depicting the front end of the main body of FIG. 7;

[0018] FIG. 10 is a perspective view depicting a rear end of the main body of FIG. 7;

[0019] FIG. 11 is another perspective view depicting a rear end of the main body of FIG. 7;

[0020] FIG. 12 is a perspective view of a side cover of the front body of the connector body of the multi-fiber optical connector of FIG. 1;

[0021] FIG. 13 is another perspective view of the side cover of FIG. 12;

[0022] FIG. 14 is a perspective view depicting a core body of the connector body of the multi-fiber optical connector of FIG. 2, the core body is viewed from a perspective showing a front end of the core body;

[0023] FIG. 15 is a front end view of the core body of FIG. 14;

[0024] FIG. 16 is another perspective view depicting the core body of FIG. 14, the core body is viewed from a perspective showing a rear end of the core body;

[0025] FIG. 17 is a perspective view depicting a rear body of the connector body of the multi-fiber optical connector of FIG. 2, the rear body is viewed from a perspective showing a front end of the rear body;

[0026] FIG. 18 is another perspective view depicting the rear body of FIG. 17, the rear body is viewed from a perspective showing a rear end of the rear body;

[0027] FIG. 19 is a perspective view depicting a coupler of the multi-fiber optical connector of FIG. 2, the coupler is viewed from a perspective showing a front end of the coupler;

[0028] FIG. 20 is another perspective view depicting the coupler of FIG. 19, the coupler is viewed from a perspective showing a rear end of the coupler;

[0029] FIG. 21 is a partially exploded view of the multi-fiber optical connector of FIG. 1;

[0030] FIG. 22 depicts the side cover of FIG. 12 being installed at an open side of the main body of FIG. 7;

[0031] FIG. 23 is a cross-sectional view of the multi-fiber optical connector of FIG. 1 taken along a cross-section plane that extends along a minor axis of a front face of the multi-fiber ferrule of the multi-fiber optical connector;

[0032] FIG. 24 is a cross-sectional view of the multi-fiber optical connector of FIG. 1 taken along a cross-section plane that extends along a major axis of a front face of the multi-fiber ferrule of the multi-the fiber optical connector;

[0033] FIG. 25 is a perspective view of a multi-fiber optical adapter adapted to receive the multi-fiber optical connector of FIG. 1;

[0034] FIG. 26 is an exploded view of the multi-fiber optical adapter of FIG. 25;

[0035] FIG. 27 is a first cross-sectional view depicting the multi-fiber optical connector of FIG. 1 coupled to a non-hardened multi-fiber optical connector via the multi-fiber optical adapter of FIG. 25;

[0036] FIG. 28 is a second cross-sectional view depicting the multi-fiber optical connector of FIG. 1 coupled to the non-hardened multi-fiber optical connector via the multi-fiber optical adapter of FIG. 25;

[0037] FIG. 29 is a perspective view depicting the multi-fiber optical connector of FIG. 1 equipped / fitted with an MPO conversion assembly for converting the multi-fiber optical connector to a non-hardened MPO form factor;

[0038] FIG. 30 is a perspective view of the MPO conversion assembly of FIG. 29

[0039] FIG. 31 is an exploded view of the MPO conversion assembly of FIG. 30;

[0040] FIG. 32 is a perspective view depicting the multi-fiber optical connector ofFIG. 1 equipped / fitted with a hardened multi-fiber plug conversion assembly;

[0041] FIG. 33 is a perspective view of the hardened multi-fiber plug conversion assembly of FIG. 32;

[0042] FIG. 34 is an exploded view of the hardened multi-fiber plug conversion assembly of FIG. 33;

[0043] FIG. 35 is a perspective view depicting the multi-fiber optical connector of FIG. 1 equipped / fitted with a hardened multi-fiber jack conversion assembly;

[0044] FIG. 36 is a perspective view of the hardened multi-fiber jack conversion assembly of FIG. 35;

[0045] FIG. 37 is an exploded view of the hardened multi-fiber jack conversion assembly of FIG. 35;

[0046] FIG. 38 is a perspective view of another multi-fiber optical connector in accordance with the principles of the present disclosure;

[0047] FIG. 39 is a perspective view of the multi-fiber optical connector of FIG. 38 with a pulling cap and inner dust cap of the multi-fiber optical connector removed;

[0048] FIG. 40 is an exploded view of the multi-fiber optical connector of FIG. 38;

[0049] FIG. 41 is a perspective view depicting a front body of a connector body of the multi-fiber optical connector of FIG. 40, the front body is viewed from a perspective showing a front end of the front body;

[0050] FIG. 42 is another front perspective view of the front body of FIG. 41 ;

[0051] FIG. 43 is a rear perspective view of the front body of FIG. 41 ;

[0052] FIG. 44 is another rear perspective view of the front body of FIG. 41;

[0053] FIG. 45 is a further rear perspective view of the front body of FIG. 41 ;

[0054] FIG. 46 is a front perspective view of a core body of the multi-fiber optical connector of FIG. 40;

[0055] FIG. 47 is another front perspective view of the core body of FIG. 46;

[0056] FIG. 48 is a rear perspective view of the core body of FIG. 46;

[0057] FIG. 49 is another perspective view of the core body of FIG. 46;

[0058] FIG. 50 is a rear perspective view of an inner core of the multi-fiber optical connector of FIG. 40;

[0059] FIG. 51 is a rear perspective view of a front ferrule holder of the inner core assembly of FIG. 50;

[0060] FIG. 52 is another rear perspective view of the front ferrule holder of FIG. 51;

[0061] FIG. 53 is a rear perspective view of a rear core of the core assembly of FIG. 50;

[0062] FIG. 54 is a front perspective view of the rear core of FIG. 53;

[0063] FIG. 55 depicts alignment pins and a pin keeper of the ferrule assembly of the multi-fiber optical connector of FIG. 40;

[0064] FIG. 56 is a front view of the alignment pins and pin keeper of FIG. 55;

[0065] FIG. 57 is a perspective view of the pin keeper of FIG. 55;

[0066] FIG. 58 is another perspective view of the pin keeper of FIG. 55;

[0067] FIG. 59 is a perspective view of a multi-fiber optical adapter configured for receiving the multi-fiber optical connector of FIG. 40;

[0068] FIG. 60 is an exploded view of the multi-fiber optical adapter of FIG. 59;

[0069] FIG. 61 is a first cross-sectional view taken along a first longitudinal cross- sectional plane cut through a splice-on version of the multi-fiber connector of FIG. 1;

[0070] FIG. 62 is a second cross-sectional view taken along a second longitudinal cross-sectional plane cut through a splice-on version of the multi-fiber connector of FIG. 1 , the second longitudinal cross-sectional plane is oriented perpendicular relative to the first longitudinal cross-sectional plane;

[0071] FIG. 63 is a perspective view of a portion of the multi-fiber connector of FIGS. 61 and 62 showing the side cover removed to expose the fiber bending cavity / fiber buckling zone of the multi-fiber connector;

[0072] FIG. 64 is a cross-sectional view of the multi-fiber connector of FIGS. 61 and 62 depicting the fiber bending cavity / fiber buckling zone of the multi-fiber connector;

[0073] FIG. 65 is another cross-sectional view of the multi-fiber connector of FIGS. 61 and 62 depicting the fiber bending cavity / fiber buckling zone of the multifiber connector;

[0074] FIG. 66 is a perspective view of a portion of the multi-fiber connector of FIGS. 61 and 62 showing an adhesive injection hole / opening and an adhesive venting hole / opening;

[0075] FIG. 67 is another perspective view of a portion of the multi-fiber connector of FIGS. 61 and 62 showing the adhesive injection hole / opening and the adhesive venting hole / opening;

[0076] FIG. 68 is a cross-sectional view of a portion of the multi-fiber connector of FIGS. 61 and 62 showing the adhesive injection hole / opening and the adhesive venting hole / opening;

[0077] FIG. 69 is an enlarged view of a front end portion of the multi-fiber connector of FIG. 1 and FIG. 62;

[0078] FIG. 70 is a cross-sectional view of the front end portion of FIG. 69; and

[0079] FIG. 71 is another cross-sectional view of the front end portion of FIG. 69.

[0080] FIG. 72 a perspective view of an alternate multi-fiber optical connector;

[0081] FIG. 73 is a cross-sectional view of the multi-fiber optical connector ofFIG. 72.DETAILED DESCRIPTION

[0082] In preferred examples, multi-fiber optical connectors in accordance with the principles of the present disclosure (e.g., multi-fiber connector 20 (see FIGS. 1 and 2), multi-fiber connector 420 (see FIGS. 38-40), etc.) are hardened (i.e., ruggedized). By hardened, it is meant that the multi-fiber connector 20, 420 has a more robust construction than a standard non-hardened multi-fiber optical connector such as a nonhardened MPO connector. In a preferred example, the multi-fiber connector 20, 420 isconfigured to withstand a pull-out force of at least 50 pounds when installed within a corresponding hardened fiber-optic adapter. In a preferred example, the multi-fiber connector 20, 420 includes environmental sealing. For example, the multi-fiber connector 20, 420 can include an elastomeric seal 36 for providing sealing (e.g., radial sealing) between the multi-fiber optical connector 20, 420 and another optical component (e.g., a hardened fiber-optic adapter, a pulling cap, and interface converter assembly, etc.) to which the multi-fiber optical connector 20, 420 is configured to couple and in which the multi-fiber connector 20, 420 is received.

[0083] FIGS. 1 and 2 depict one example multi-fiber optical connector 20 in accordance with the principles of the present disclosure. The multi-fiber optical connector 20 is configured to be installed at the end of a multi-fiber optical cable 22. The multi-fiber optical connector 20 includes a connector body 24 having a front end 26 and a rear end 28. The multi-fiber optical connector 20 includes a ferrule assembly 30 that mounts at the front end 26 of the connector body 24 and the multi-fiber optical cable 22 couples to the rear end 28 of the connector body 24. The multi-fiber optical connector 20 also includes a tum-to-engage coupler 32 that rotatably mounts on the connector body 24 and is configured for coupling the multi-fiber optical connector with another optical component such as a hardened fiber optic adapter, a pulling cap, and / or an interface converter assembly. In the depicted example, a resilient boot 34 mounts over the tum-to-engage coupler 32 and is configured to extend over a rear portion of the connector body 24.

[0084] The multi-fiber optical cable 22 is depicted including a jacket 40 defining an elongate cross-sectional profile having perpendicular major and minor dimensions with the major dimension being larger than the minor dimension. As shown at FIG. 24, the multi-fiber optical cable 22 includes strength members 42 (e.g., fiberglass reinforced polymeric rods; but in other examples could include yams such as Aramid) positioned along the major dimension. A buffer tube can be positioned between the strength members 42. A plurality of optical fibers 44 can be positioned within the buffer tube and can include forward portions that extend beyond the jacket 40 into the multi-fiber optical connector 20. The optical fibers 44 can include ribbonized portions within the connector body 24 and can include bare fiber portions secured within openings 43 (e.g., one or more rows of openings) defined by a multi-fiber ferrule 46 of the ferrule assembly 30. A shape memory sleeve 48 (e.g., a heat-shrink sleevecontaining adhesive) can be positioned at the junction between the rear end 28 of the connector body 24 and the multi-fiber optical cable 22. The shape memory sleeve 48 can be bonded to an exterior of the rear end 28 of the connector body 24 and to an exterior of the jacket 40 and can provide sealing between the multi-fiber optical cable 22 and the connector body 24. The strength members 42 can be adhesively bonded within the interior of the rear end 28 of the connector body 24. It will be appreciated that alternative multi-fiber optical cables can also be used. For example, multi-fiber optical cables having round cross-sectional profiles and including fibrous, tensile strength members such as Aramid yam can also be used. Alternative fiber-optic cables and cable anchoring techniques that can be utilized are disclosed by PCT International Publication No. W02024 / 050543, which is hereby incorporated by reference in its entirety.

[0085] The ferrule assembly 30 includes the multi-fiber ferrule 46, a spacer 50, and a ferrule spring 52 (see FIGS. 2, 23 and 24). The spacer 50 is positioned between the spring 52 and the multi-fiber ferrule 46. The spring 52 is adapted to engage the spacer 50 to bias the multi-fiber ferrule 46 in a forward direction relative to the front end 26 of the connector body 24. It will be appreciated that the multi-fiber ferrule 46 can be configured as a male ferrule or a female ferrule. When the multi-fiber ferrule 46 is configured as a male ferrule, alignment pins are supported by the spacer 50, extend through alignment openings 47 (see Fig. 24) defined by the ferrule and project forwardly from the multi-fiber ferrule 46. When the multi-fiber ferrule 46 is configured as a female ferrule, the alignment pin openings 47 defined by the multi-fiber ferrule 46 are open. When two multi-fiber optical connectors are mated together, one of the multifiber optical connectors includes a female multi-fiber ferrule and the other multi-fiber optical connector includes a male multi-fiber ferrule with the alignment pins of the male multi-fiber ferrule being received within the openings of the female multi-fiber ferrule to achieve alignment between the optical fibers of the multi-fiber ferrules. A female version of the multi-fiber ferrule 46 is shown at FIGS. 3 and 24 while a male version of the multi-fiber ferrule 46 having alignment pins 301 is shown at FIGS. 40 and 50. In the depicted example, the multi-fiber ferrule 46 is a standard MPO ferrule.

[0086] The multi-fiber ferrule 46 is shown at FIGS. 3-6. The multi-fiber ferrule 46 has an optical connection end 54 (see FIG.3) and a fiber entrance end 56 (see FIG. 4). As shown at FIG. 5, the optical connection end 54 defines a major axis Aland a minoraxis A2 that are perpendicular with respect to each other. The optical connection end 54 has a major dimension DI that extends along the major axis Al and a minor dimension D2 that extends along the minor axis A2. The major dimension DI is longer than the minor dimension D2. The multi-fiber ferrule 46 has opposite major sides 58 and opposite minor sides 60 that extend between the optical connection end 54 and the fiber entrance end 56. The major sides 58 of the multi-fiber ferrule 46 are separated by the minor dimension D2 of the optical connection end 54 and the minor sides 60 are separated by the major dimension DI of the optical connection end 54. The multi-fiber ferrule 46 has side flanges 62 that project outwardly from the minor sides 60 of the multi-fiber ferrule 46. The multi-fiber ferrule 46 also includes shoulders 64 that project outwardly from the major sides 58 of the multi-fiber ferrule 46. The fiber openings 43 as well as the optical fibers 44 are arranged in a row that extends along the major axis Al. Thus, the optical fibers 44 are spaced apart from one another in an orientation that extends along the major axis Al. The alignment openings 47 are also positioned along the major axis Al with the optical fibers 44 being positioned between the alignment openings 47.

[0087] The front end 26 of the connector body 24 defines an opening 66 through which the multi-fiber ferrule 46 protrudes such that the optical connection end 54 of the multi-fiber ferrule 46 is accessible at the front end 26 of the connector body 24. The connector body 24 defines side through-openings 68 at opposite sides of the connector body 24. The side through-openings 68 are open at an exterior of the connector body 24. The side flanges 62 of the multi-fiber ferrule 46 are received within the side through-openings 68 (see FIGS. 1, 24, 69 and 71).

[0088] The optical fibers 44 extend from an end of the jacket 40 of the multi-fiber cable 22 through the connector body and into the multi-fiber ferrule 46 through the fiber entrance end 56 of the multi-fiber ferrule 46. The optical fibers 44 have front end portions secured within the openings 43 of the multi-fiber ferrule 46 and have end faces at the optical connection end 54 of the multi-fiber ferrule 46. The front end portions of the optical fibers 44 are arranged in a row that extends along the major axis Al of the optical connection end 54 of the multi-fiber ferrule 46.

[0089] Front ends 70 of the side through-openings 68 are defined by rearwardly facing surfaces 71 (see FIGS. 10 and 11) that are rearwardly offset from the front end 26 of the connector body 24. The rearwardly facing surfaces 71 are configured to stopforward movement of the multi-fiber ferrule 46 relative to the connector body 24 via interaction with the side flanges 62 of the multi-fiber ferrule 46. The multi-fiber ferrule 46 is spring biased in a forward direction with respect to the connector body 24 by the ferrule spring 52 causing the side flanges 62 to abut against the front ends 70 when the multi-fiber ferrule 46 is biased to a forwardmost position with respect to the connector body 24.

[0090] The front opening 66 can have a chamfered configuration that works in cooperation with the side opening 68 to prevent interference with floating rearward movement of the multi-fiber ferrule 46 against the bias of the ferrule spring 52. For example, opposite minor sides 67 (see FIG. 24) and opposite major sides 69 (see FIG. 23) defining the front opening 66 can be angled at oblique angles relative to the central axis 79. The connector can be manufactured with different fiber counts, and ferrule springs having the same shape but different spring forces (e.g., 10 Newtons, 20 Newtons) can be paired with corresponding ferrules (e.g., ferrules with larger fiber counts can be paired with ferrule springs having larger spring forces).

[0091] Referring to FIG. 1, the connector body 24 includes a front body 72, a core body 74 and a rear body 76 that are coupled together in end-to-end relation with the core body 74 secured between the front body 72 and the rear body 76. When coupled together, the front body 72, the core body 74, and the rear body 76 co-axially align along a central axis 79 of the multi-fiber optical connector 20. In one example, the front body 72, the core body 74, and the rear body 76 can be secured together by snap- fit connection interfaces.

[0092] The front body 72 includes a main body 80 (see FIGS. 7-11) and a side cover 82 (see FIGS. 12 and 13). The front body 72 has first and second opposite ends 84, 86. The first end 84 of the front body 72 forms the front end 26 of the connector body 24. The front body 72 defines the front opening 66 and the side through-openings 68 of the connector body 24. The front body 72 has an open-sided configuration having a single open side 88 that extends from one of the rearwardly facing surfaces 71 to the second end 86 of the front body 72. The open side 88 of the front body 72 is defined by the main body 80 of the front body 72. The side cover 82 mounts to the main body 80 to cover a rear portion of the open side 88 when the front body 72 is assembled. A front portion of the open side 88 defines one of the side through- openings 68 when the side cover 82 is mounted to the main body 80. The side cover 82includes a rear spring stop 104 for opposing a rear end of the ferrule spring 52 that biases the multi-fiber ferrule 46 forwardly relative to the connector body 24. The side cover 82 also includes snap-latches 103 for securing the side cover 82 to the main body 80 by a snap-fit connection. The snap-latches 103 can snap into retention openings 105 provided within slots defined within the interior of the main body 80. The openings 105 can extend through walls defining opposite major sides 89, 90 of the front body 72.

[0093] As depicted, the side through-openings 68 are defined at opposite minor sides 91, 92 of the front body 72. The major sides 89, 90 are located between the minor sides 91, 92. A longitudinal key 106 is provided at the major side 89 of the front body 72. A pair of ramped, snap-fit projections 107 are also provided at the major side 89 at a location rearwardly offset from the longitudinal key 106. The longitudinal key 106 is aligned along a centerline of the front body 72, while the projections 107 are positioned on opposite sides of the centerline. Stop surfaces of the snap-fit projections 107 oppose a forwardly facing retention surface 108 defined by a shoulder at the major side 89. A similar shoulder defines a forwardly facing retention surface 109 at the major side 90. A ramped, snap-fit projection 110 is provided at the major side 90 with a stop surface facing toward the forwardly facing retention service 109. The snap-fit projection 110 extends across a majority of a width of the major side 90 and is bisected by a centerline of the front body 72. The front body 72 defines a reduced cross-sectional profile section 112 at the second end 86. Ramped snap-fit projections 114 are provided at an exterior of the reduced cross-sectional profile section 112. The ramped snap-fit projections 114 are located at the major sides 89, 90 of the front body 72 and are positioned within exterior longitudinal channels 116 defined at opposite sides of the reduced cross- sectional profile section 112.

[0094] Referring to FIGS. 14-16, the core body 74 has a first end 118 and an opposite second end 120. The first end 118 of the core body 74 attaches to the second end 86 of the front body 72 such that the front body 72 and the core body 74 are coupled in co-axial alignment with each other along the central axis 79. As depicted, the core body 74 has a molded, one-piece construction (e.g., a molded plastic one-piece unitary construction). The core body 74 defines an outer circumferential groove 122 that extends around the central axis 79 for receiving the elastomeric seal 36. The core body 74 includes an exterior shoulder 124 positioned rearward of the circumferential groove 122. The tum-to-engage coupler 32 rotatably mounts over the core body 74 andthe exterior shoulder 124 is configured to stop forward movement of the coupler 32 relative to the core body 74. For example, interior stop surfaces within the tum-to- engage coupler 32 can oppose a rear retention surface defined by the exterior shoulder 124. The reduced cross-sectional profile section 112 at the second end 86 of the front body 72 is configured to fit inside the first end 118 of the core body 74 in a mating relationship. The first end 118 of the core body 74 includes internal longitudinal rails 126 that fit within the longitudinal channels 116 provided at the reduced cross-sectional profile section 114 of the front body 72. The longitudinal rails 126 define retention openings 128 that receive the ramps snap-fit projections 114 provided at the reduced cross-sectional profile section 112. When the front body 72 and the core body 74 coupled together, an end-most surface 130 at the second end 86 of the front body 72 opposes and interior shoulder 132 within the core body 74 and an end-most surface 134 at the first end 118 of the core body 74 opposes a rearwardly facing surface 136 defined by the front body 72 immediately in front of the reduced cross-sectional profile section 112.

[0095] Referring to FIGS. 17 and 18, the rear body 76 of the connector body 24 has a first end 138 and an opposite second end 140. The first end 138 of the rear body 76 attaches to the second end 120 of the core body 74 such that the rear body 76 and the core body 74 are coupled in co-axial alignment with each other along the central axis 79. The second end 140 of the rear body 76 defines the rear end 28 of the connector body 24. The rear body 76 is configured for receiving the fiber optic cable 22. For example, the strength members 42 and the jacket 40 of the fiber-optic cable 22 can be adhesively bonded (e.g., via epoxy) within the rear body 76. The rear body 76 can include extensions 142 with teeth that embed into the jacket 40. The first end 138 of the rear body 76 can include latching extensions 144 that snap within corresponding receptacles defined within the second end 120 of the core body 74. The rear body 76 can include a key 146 that fits within a receptacle 147 at the second end 120 of the core body 74 to ensure proper rotational alignment between the core body 74 and the rear body 76.

[0096] FIGS. 19 and 20 depicts the tum-to-engage coupler 32 of the multi-fiber optical connector 20. In the depicted example, the tum-to-engage coupler 32 is a quarter turn coupler of the type disclosed in PCT International Publication No.WO2021 / 041305, which is hereby incorporated by reference in its entirety. Thedepicted tum-to-engage coupler includes an internal coupling / retention arrangement 150 adapted to interlock with a corresponding external coupling / retention arrangement provided on a component desired to be axially coupled with respect to the multi-fiber optical connector 20 (e.g., a hardened fiber-optic adapter, a pulling cap, and interface converter assembly, etc.). In other examples, alternative types of coupling / retention arrangements can be used such as threaded coupling / retention arrangements or bayonetstyle coupling / retention arrangements.

[0097] As depicted at FIGS. 23 and 24, an internal fixation region 23 of the connector body 24 can be filled with an adhesive material such as epoxy (e.g., through one or more adhesive injection ports 29) to anchor the strength members 42 within the connector body 24. The internal fixation region 23 can coincide with a rear portion of the core body 74 and a front portion of the rear body 76. At the front of the region 23, the optical fibers can pass through an opening in a barrier 25 that limits forward migration of the adhesive during filling of the region 23. In certain examples, the optical fibers are arranged in a loose configuration within the cable 22 and transition to a parallel, planar configuration at transition region 27 within the internal fixation region 23. A fiber buckling zone 31 is defined within the connector body 24 between the barrier 25 and a rear end of the spring 52. The portions of the optical fibers extending through the fiber buckling zone 31 can be ribbonized or non-ribbonized. In one example, the portions of the optical fibers extending through the fiber buckling zone 31 are arranged in a generally parallel, planar configuration but are moveable relative to one another (e.g., not bonded together by matrix material) to allow for independent bending of the optical fibers to accommodate rearward movement of the ferrule relative to the connector body 24. This prevents the fibers from having a preferential bend direction and reduces the resistance to rearward movement of the ferrule by the optical fibers. The spring 52 is configured to compress as the ferrule 46 is moved rearwardly relative to the connector body 24. A vent opening or vent openings can be provided through the connector body 24 at the internal fixation region at locations offset from the injection port or ports 29 to facilitate filling the internal fixation region with adhesive. In one example, the internal fixation region can be filled with adhesive until the adhesive begins exiting the internal fixation region through the one or more vent openings. In one example, a vent opening is provided adjacent the barrier 25 and the injection port 29 is at the rear of the region 23. The loose optical fibers 44 from thecable can be routed around the strength members 42 within the core body 74 and the rear body 76. In an alternative example, as compared to the example of FIGS. 23 and 24, the rear body 76 can be rotated 90 degrees with respect to the core body 74 such that the strength members 42 are aligned along a plane perpendicular with respect to the major axis of the front face of the ferrule 46 to facilitate routing the optical fibers 44 between the strength members 42.

[0098] The side cover 82 can attach to the main body 80 via at least 3 snap-fit connection locations 81a, 81b, 81c (see FIG. 63) along each longitudinal edge of the cover 82 and can be bonded to the main body 80 at a location immediately rearward of the barrier 25. The side cover can include an inner wall portion 83 (see FIG. 65) that defines a portion of the barrier 25 and also includes an adhesive vent port 33 (see FIGS. 63 and 65-68) adjacent the inner wall portion 83. An overlap configuration can be provided at the interface between the front body 72 and the core body 74 to prevent leakage of adhesive from the internal fixation region 23 as the internal fixation region 23 is filled with adhesive. The rear of the side cover 82 can overlap a first portion of the front of the core body 74 and a second portion of the front of the core body 74 can overlap the rear of the main body 80 (see FIG. 68).

[0099] FIGS. 21 and 22 depict portions of an assembly process for assembling the multi-fiber optical connector 20. Referring to FIG. 21, the multi-fiber ferrule 46 is connected to the optical fibers 44 of the fiber-optic cable 22 either by a direct termination in which the optical fibers 44 of the fiber-optic cable 22 are directly bonded within the ferrule 46 (see FIGS. 23 and 24), or by a splice-on termination in which fiber stubs pre-secured within the ferrule 46 are optically spliced to the optical fibers 44 of the fiber-optic cable 22 (see FIGS. 61 and 62). Termination is completed while the front body 72 is disconnected from the core body 74. The ferrule spring 52 is preferably positioned over the optical fibers 44 prior to termination of the ferrule 46. After termination, the multi-fiber ferrule 46 can be loaded into the main body 80 of the front body 72 through the open side 88 and inserted through the front opening 66 of the front body 72. The side cover 82 can then be installed on the main body 80 to cover the rear portion of the open side 88 and to compress the ferrule spring 52. The spring stop 104 is configured to straddle the optical fibers 44. Once the optical fibers are straddled by the spring stop 104, the side cover 82 is moved forwardly relative to the main body 80 (see FIG. 22) to the compress the ferrule spring 52. The side cover 82 is then snappedinto place with respect to the main body 80 to provide coverage of the rear portion of the open side 88 and to maintain the ferrule spring 52 in a compressed state which biases the multi-ferrule 46 in a forward direction relative to the front body 72.

[0100] FIGS. 25-28 depict a hardened fiber-optic adapter 200 for coupling the multi-fiber optical connector 20 to a standard non-hardened multi-fiber connector such as a standard non-hardened MPO connector 202. The hardened fiber-optic adapter 200 includes a hardened port 204 for receiving the multi— fiber optical connector 20 and a non-hardened port 206 for receiving the MPO connector 202. The hardened port 204 includes a coupling / retention arrangement 207 adapted to interlock with the coupling / retention arrangement 150 of the tum-to-engage coupler 34 to couple the multi-fiber optical connector 20 to the hardened fiber-optic adapter 200. The nonhardened port 206 includes resilient latches 208 that are received within receptacles 210 defined by the MPO connector 202 to secure the MPO connector 202 within the nonhardened port 206. As depicted, alignment between the multi-fiber ferrule 46 of the multi-fiber optical connector 20 and a corresponding multi-fiber ferrule 212 of the MPO connector 202 is provided by alignment pins 214 coupled to the multi-fiber ferrule 212 which fit within the alignment openings 47 of the multi-fiber ferrule 46. The hardened fiber-optic adapter 200 is configured to be mounted within an opening 216 defined by a structure such as an enclosure (e.g., a sealed terminal). The hardened fiber-optic adapter 200 includes a main body 217 defining external threads 218 that engage with internal threads of a coupling nut 220 to allow the fiber-optic adapter 200 to be clamped within the opening 216. An axial face seal 222 can be used to provide sealing at the opening 216. The hardened fiber-optic adapter 200 further includes a retention sleeve 226 and a dust cap 228 tethered to the hardened fiber-optic adapter 200 by a lanyard 230. The dust cap 228 can include an internal seal 231 that provides sealing within the hardened port 204. The dust cap 228 can be used to close / seal the hardened port 204 when the hardened port 204 is not occupied by a fiber optic connector. The retention sleeve 226 can be of the type disclosed by PCT International Publication No. W02021 / 041305, which is hereby incorporated by reference in its entirety.

[0101] FIG. 29 depicts the multi-fiber optical connector 20 of FIG. 1 equipped / fitted with an MPO conversion assembly 250 for converting the hardened multi-fiber optical connector 20 to a non-hardened MPO form factor that can mate with(i.e., is compatible with) a standard non-hardened MPO fiber optic adapter. As best shown at FIGS. 30 and 31, the MPO conversion assembly 250 includes an MPO conversion housing 252, an MPO release sleeve 254 and release sleeve biasing springs 256. The MPO conversion housing 252 is adapted to slide axially over the front end 26 of the multi-fiber optical connector 20. As the MPO conversion housing 252 is slid rearwardly with respect to the connector body 24, the MPO conversion housing 252 interlocks with the connector body 24 via a snap-fit connection interface to inhibit unintentional removal of the MPO conversion housing 252 from the connector body 24 in a forward direction.

[0102] The MPO conversion housing 252 has major sides that are primarily open and minor sides that define receptacles 260 adapted to engage with latches of a standard MPO fiber-optic adapter. The minor sides of the MPO conversion housing 252 further define elongate pockets 262 for receiving the release sleeve biasing springs 256. The MPO release sleeve 254 mounts over the MPO conversion housing 252 and is biased in a forward direction relative to the MPO conversion housing 252 by the release sleeve biasing springs 256. The MPO release sleeve 254 is axially movable relative to the MPO conversion housing 252 against the bias of the springs 256 from a forward position to a rearward position.

[0103] When the converted multi-fiber optical connector 20 of FIG. 29 is inserted into a standard MPO fiber-optic adapter, the latches of the standard MPO fiber-optic adapter fit within the receptacles 260 and the MPO release sleeve 254 (when in the forward position) is configured to prevent the latches from flexing outwardly such that the converted multi-fiber optical connector 20 is prevented from being axially pulled from the standard MPO fiber-optic adapter. By moving the MPO release sleeve 254 from the forward position to the rearward position by pulling on the MPO release sleeve 254, the MPO release sleeve 254 no longer covers the latches of the standard MPO fiber-optic adapter such that the latches can resiliently flex outwardly in response to pulling of the MPO release sleeve 254 to allow the converted multi-fiber optical connector to be withdrawn from the standard non-hardened MPO fiber-optic adapter.

[0104] One of the major sides of the MPO conversion housing 252 includes a key extender 270 that aligns with the longitudinal key 106 of the multi-fiber optical connector 20 and extends the key 106 in a forward direction. A forward portion 272 of the MPO conversion housing 252 encloses / covers / shrouds a portion of the multi-fiberferrule 46 that projects forwardly beyond the front end 26 of the connector body 24. A rear portion 274 of the MPO conversion housing 252 includes crossbars 276 that extend across the major sides of the MPO conversion housing 252. The crossbars 276 at the same major side of the MPO conversion housing 252 as the key extender 270 can include a slot 277 for accommodating the longitudinal key 106 when the MPO conversion housing 252 is installed on the connector body 24 of the multi-fiber optical connector 20. The crossbars 262 can have a resilient construction and can be configured to snap past the ramped, snap-fit projections 107 and the ramped snap-fit projection 110 positioned on opposite major sides of the connector body 24 to secure the MPO conversion housing 252 to the connector body 24. In the secured position, the crossbars 262 are captured between rearwardly facing stop surfaces of the snap-fit projections 107, 110 and the forwardly facing retention surfaces 108, 109 defined by the shoulders at the major sides of the connector body 24.

[0105] FIG. 32 depicts the multi-fiber optical connector 20 of FIG. 1 equipped / fitted with a hardened multi-fiber plug conversion assembly 280 for converting the hardened multi-fiber optical connector 20 to a hardened multi-fiber optical plug having an enlarged formfactor as compared to the multi-fiber connector 20. In one example, the hardened multi-fiber plug conversion assembly 280 converts the multi-fiber optical connector 20 into an HMFOC (Hardened Multi-Fiber Optical Connector) plug of the type sold by Commscope Technologies LLC of Claremont North Carolina. As best shown at FIGS. 33 and 34, the hardened multi-fiber plug conversion assembly 280 includes a hardened plug converter housing 282, a seal 283 that mounts over the hardened plug converter housing 282, a retention nut 284 and one of the retention sleeves 226. The hardened plug converter housing 282 includes a first end 286 and a second end 288. The first end 286 includes a key slot 287 and an opening 289 for accessing the multi-fiber ferrule 46 within the hardened plug converter housing 282 when the hardened plug converter housing 282 is mounted over the connector body 24 of the multi-fiber optical connector 20. The second end 288 includes the coupling / retention arrangement 207 adapted to engage with the coupling / retention arrangement 150 of the tum-to-engage coupler 32 to secure the converter housing 282 on the connector body 24. To secure the hardened plug converter housing 282 on the connector body 24, the hardened plug converter housing 282 is slid axially in a rearward direction over the front end 26 of the connector body 24 and then is secured tothe fiber-optic connector 20 by the tum-to-engage coupler 32 and the retention sleeve 226. The retention nut 284 includes internal threads. It will be appreciated that the converted multi-fiber optical connector of FIG. 32 is adapted to be optically connected with a hardened multi-fiber optical jack such as the hardened multi-fiber optical jack of FIG 35.

[0106] FIG. 35 depicts the multi-fiber optical connector 20 of FIG. 1 equipped / fitted with a hardened multi-fiber jack conversion assembly 380 for converting the hardened multi-fiber optical connector 20 to a hardened multi-fiber optical jack. In one example, the hardened multi-fiber jack conversion assembly 380 converts the multi-fiber optical connector 20 into an HMFOC jack of the type sold by Commscope Technologies LLC of Claremont North Carolina that is mateable with a standard Commscope HMFOC plug and with the converted HMFOC plug of FIG 32. As best shown at FIGS. 36 and 37, the hardened multi-fiber jack conversion assembly 380 includes a hardened jack converter housing 382 and one of the retention sleeves 226. The hardened jack converter housing 382 includes a first end 386 and a second end 388. The first end 386 includes exterior threads 387 and an opening 389 for accessing the multi-fiber ferrule 46 within the hardened jack converter housing 382 when the hardened jack converter housing 382 is mounted over the connector body 24 of the multi-fiber optical connector 20. The second end 388 includes the coupling / retention arrangement 207 adapted to engage with the coupling / retention arrangement 150 of the tum-to-engage coupler 32 to secure the hardened jack converter housing 382 on the connector body 24. To secure the hardened jack converter housing 382 on the connector body 24, the hardened jack converter housing 382 is slid axially in a rearward direction over the front end 26 of the connector body 24 and then is secured to the fiber-optic connector 20 by the tum-to-engage coupler 32 and the retention sleeve 226. When coupled to an HMFOC plug, the threads 387 engage with internal threads of a coupling nut (e.g., coupling nut 284) of the HMFOC plug, an end of the HMFOC plug (e.g., end 286) is received within the opening 389 and a seal of the HMFOC plug (e.g., seal 283) seals within the opening 389. It will be appreciated that one of the HMFOC plug and the HMFOC jack would include a male multi-fiber ferrule and the other of the HMFOC plug and the HMFOC jack would include a female multifiber ferrule.

[0107] As used herein, term MPO connectors includes MTP® connectors sold by US Conec of Hickory North Carolina.

[0108] FIGS. 38-40 depict another example multi-fiber optical connector 420 in accordance with the principles of the present disclosure. The multi-fiber optical connector 420 is configured to be installed at the end of the multi-fiber optical cable 22 or other type of multi-fiber cable (e.g., a cable having a round cross-sectional profile and Aramid yam reinforcement as described above). The multi-fiber optical connector 420 utilizes many of the same components described with respect to the multi-fiber optical connector 20 and the above descriptions of such components with respect to the multi-fiber optical connector 20 also apply to the multi-fiber optical connector 420. Example components include the multi-fiber ferrule 46, optical fibers 44, the ferrule spring 52, the shape memory sleeve 48, the boot 34, the elastomeric seal 36, and the tum-to-engage coupler 32. FIGS. 38 and 40 depict the multi-fiber optical connector 420 in combination with a pulling cap 403 and a press-on dust cap 405. The pulling cap 403 can be coupled to the multi-fiber optical connector 420 by the tum-to-engage coupler 32 and can function to protect the multi-fiber ferrule 46 and to allow the multifiber optical connector 420 and fiber optic cable 22 to be pulled through a structure such as a duct or other structure. The press-on dust cap 405 can be press fit on the multi-fiber ferrule 46 to further protect the multi-fiber ferrule 46. The press-on dust cap 405 can remain on the multi-fiber ferrule 46 with the pulling cap 403 installed on the multi-fiber optical connector 420.

[0109] The multi-fiber optical connector 420 includes a connector body 424 having a front end 426 and a rear end 428. The multi-fiber optical connector 420 includes the multi-fiber ferrule 46 that mounts at the front end 426 of the connector body 424. The multi-fiber optical cable 22 enters the connector body 424 through the rear end 428 of the connector body 424. The multi-fiber optical connector 420 also includes the tum-to-engage coupler 32 that rotatably mounts on the connector body 424 and is configured for coupling the multi-fiber optical connector 420 with another optical component such as a hardened fiber optic adapter, a pulling cap, and / or an interface converter assembly. In the depicted example, the resilient boot 34 mounts over the tum-to-engage coupler 32 and is configured to extend over a junction between the connector body 424 and the multi-fiber cable 22.

[0110] The front end 426 of the connector body 424 defines an opening 466 through which the multi-fiber ferrule 46 protrudes such that the optical connection end 54 of the multi-fiber ferrule 46 is accessible at the front end 426 of the connector body 424. The connector body 424 defines side through-openings 468 at opposite sides of the connector body 424. The side through-openings 468 are open at an exterior of the connector body 424. The side flanges 62 of the multi-fiber ferrule 46 are received within the side through-openings 468 (see FIG. 39).

[0111] The optical fibers 44 extend from an end of the jacket 40 of the multi-fiber cable 22 through the connector body 424 and into the multi-fiber ferrule 46 through the fiber entrance end 56 of the multi-fiber ferrule 46. The optical fibers 44 have front end portions secured within the openings 43 of the multi-fiber ferrule 46 and have end faces at the optical connection end 54 of the multi-fiber ferrule 46. The front end portions of the optical fibers 44 are arranged in a row that extends along the major axis Al of the optical connection end 54 of the multi-fiber ferrule 46.

[0112] Front ends 470 of the side through-openings 468 are defined by rearwardly facing surfaces 471 (see FIGS. 41-45) that are rearwardly offset from the front end 426 of the connector body 424. The rearwardly facing surfaces 471 are configured to stop forward movement of the multi-fiber ferrule 46 relative to the connector body 424 via interaction with the side flanges 62 of the multi-fiber ferrule 46. The multi-fiber ferrule 46 is spring biased in a forward direction with respect to the connector body 424 by the ferrule spring 52 causing the side flanges 62 to abut against the front ends 470 when the multi-fiber ferrule 46 is biased to a forwardmost position with respect to the connector body 424.

[0113] Referring to FIG. 40, the connector body 424 includes a front body 472 and a core body 474 that are coupled together in end-to-end relation. When coupled together, the front body 472 and the core body 474 co-axially align along a central axis 479 of the multi-fiber optical connector 420. In one example, the front body 472 and the core body 474 can be secured together by snap-fit connection interfaces. The multifiber optical connector 420 also includes an inner core 480 that mounts within the connector body 424 and is adapted for supporting the ferrule assembly 30.

[0114] As best shown at FIGS. 41-45, the front body 472 includes first and second opposite ends 484, 486. The first end 484 of the front body 472 forms the front end 426 of the connector body 424. The front body 472 defines the side through-openings468 of the connector body 424. The front body 472 has an open-sided configuration having first and second opposite open sides 488 that extend from the rearwardly facing surfaces 471 to the second end 486 of the front body 472. The open sides define the side-through openings 468 which are elongate and have closed ends defined by the rearwardly facing surface 471 and open ends at the second end 486 of the front body 472. The elongate side through-openings 468 have lengths that extend for at least 75 percent of a total length of the front body 472. As shown at FIG. 39, the front body 472 defines a rotational keying feature in the form of a longitudinal groove 491. The groove 491 is rotationally offset from the side through-openings 468 (e.g., by a rotational offset angle in the range of 85-95 degrees) and extends from the first end 484 to the second end 486 of the front body 472.

[0115] In certain examples, the open sides can include notches 489 in communication with the side through-openings 468 that align generally with an alignment pin keeper 450 (i.e., pin holder) of the ferrule assembly for allowing alignment pin latches 500 of the keeper 450 to be accessed through the open sides (e.g., via a tool). Manipulation of the alignment pin latches 500 allows the alignment pins 301 to be released to facilitate conversion between a male ferrule configuration and a female ferrule configuration. Referring to FIGS. 55-58, the latches 500 include retention portions 501 that fit within grooves 502 defined by the alignment pins 301 to lock the pins 301 axially in place with respect to the pin keeper 450. The latches 500 include tabs 504 that align with the notches 489. The latches 500 can be resilient cantilever style latches that can be flexed outwardly (e.g., toward or into the side through-openings 468) from retaining positions in which the pins 301 are retained in the ferrule 46 to release positions in which the pins 301 can be pulled axially in a forward direction from the ferrule 46. The latches 500 are biased by their own elasticity toward the retaining positions. By inserting a tool through the notches 489 and behind the tabs 504, the tool can be used as a lever to engage each tab 504 and flex each latch 500 outwardly away from their corresponding pin 301 from the retaining position to the release position. Thus, the latches can be accessed and manipulated through the sides of the connector 420 without needing to disassemble the connector 420.

[0116] Referring to FIGS. 46-49, the core body 474 includes a first end 475 and an opposite second end 477. The first end 475 of the core body 474 attaches to thesecond end 486 of the front body 472 via a snap-fit connection. The front body 472 and the core body 474 are coupled in co-axial alignment with each other along a central axis 479. The core body 474 has a molded, one-piece construction and defines an outer circumferential groove 481 that extends around the central axis 479. The elastomeric seal 36 mounts in the circumferential groove 481. The second end 477 defines the rear end 428 of the connector body 424. The second end 486 of the front body 472 incudes resilient latching extensions 491, 493 respectively having snap-fit projections 494, 495 that snap within respective openings 496, 497 defined at the first end 475 of the core body 474. Latching extension 491 includes one snap-fit projection 494 and latching extension 493 includes two spaced-apart snap-fit projections 495. The opening 496 matches with the snap-fit projection 494 and openings 497 match with the snap-fit projections 495 to ensure assembly of front body 472 in the proper rotational position with respect to the core body 474.

[0117] Referring to FIGS. 51-52, the inner core 480 includes a front ferrule holder 550 having resilient latches 552 that engage the shoulders 64 at the major sides of the multi-fiber ferrule 46 to secure the multi-fiber ferrule at a front end of the inner core 480. The front ferrule holder also defines a spring pocket 554 in which the spring 52 is located. The spring 52 is configured for biasing the multi-fiber ferrule 46 in the forward direction and is captured in the pocket 554 behind the ferrule 46. Referring to FIGS. 50, 53 and 54, the inner core 480 also includes a rear inner core 556 having a first end 557 to which the front ferrule holder 550 attaches and a second end 558 to which the cable 22 attaches. The rear inner core 556 includes a main body 560 that extends from the first end 557 to the second end 558 and has an open sided configuration along its length. Snaps 562 are provided adjacent the second end 558. A cable anchoring region 564 is also provided adjacent the second end 558 for anchoring the cable 22 (e.g., via adhesive). Once the cable is positioned in the main body 560, the anchoring region 564 can be covered by a side cover 566.

[0118] The inner core 480 mounts within the connector body 424 and is loaded into the connector body 424 through the second end 477 of the core body 474. The inner core 480 can be assembled with the ferrule assembly and the cable (as shown at FIG. 50) prior to loading into the connector body 424. The snaps 562 of the inner core 480 fit within openings 568 of the connector body 424 to secure the inner core 480within the connector body 424. Adhesive can also be sued to further anchor the inner core 480 within the connector body 424.

[0119] FIGS. 59 and 60 depict a hardened fiber-optic adapter 600 for coupling the multi-fiber optical connector 420 to a standard non-hardened multi-fiber connector such as a standard non-hardened MPO connector 202. The hardened fiber-optic adapter 600 includes a hardened port 604 for receiving the multi— fiber optical connector 420 and a non-hardened port 606 for receiving the MPO connector. The hardened port 604 includes a coupling / retention arrangement 207 adapted to interlock with the coupling / retention arrangement 150 of the tum-to-engage coupler 32 to couple the multi-fiber optical connector 420 to the hardened fiber-optic adapter 600. The nonhardened port 606 includes resilient latches 608 that are received within receptacles defined by the MPO connector to secure the MPO connector within the non-hardened port 606. The hardened fiber-optic adapter 600 is configured to be mounted within an opening (e.g., opening 216) defined by a structure such as an enclosure (e.g., a sealed terminal). The opening is not round and has flat sides. The hardened fiber-optic adapter 600 includes a main body 617 defining external threads 618 that engage with internal threads of a coupling nut 620 to allow the fiber-optic adapter 602 to be clamped within the opening. The threads 618 are discontinuous and have two threaded portions 621 separated by unthreaded flats 619. The cross-sectional profile defined by the flats and the threaded portions allows the main body to be inserted through the non-round opening. After the main body 617 has been inserted through the opening, a thread supplement member 660 can be mounted on the main body 617. The thread supplement member 660 includes spaced-apart thread extensions 663 that fit over the unthreaded flats 619. The thread extensions 663 have exterior threads 665 that align with the threads 618 of the threaded portions 621 to provide continuous threads about the main body 617. The thread extensions 663 are connected by a C-shaped support 665 that fits over the main body 617. By providing continuous threads, the coupling nut 620 can provide greater clamping force. An axial face seal 622 can be used to provide sealing at the opening. The hardened fiber-optic adapter 600 further includes a retention sleeve 626 and a dust cap 628 tethered to the hardened fiber-optic adapter 600 by a lanyard 630. The dust cap 628 can include an internal seal 631 that provides sealing within the hardened port 604. The dust cap 628 can be used to close / seal the hardened port 604 when the hardened port 604 is not occupied by a fiber opticconnector. The retention sleeve 626 can be of the type disclosed by PCT International Publication No. W02021 / 041305, which is hereby incorporated by reference in its entirety.

[0120] While the multi-fiber connectors 20, 420 have been depicted as including 12 optical fibers, it will be appreciated that multi-fiber connectors in accordance with the principles of the present disclosure can be provided with other fiber counts (e.g., 16 optical fibers, 24 optical fibers). In certain examples, the optical fibers routed through the connectors can be coated fibers coated with a polymeric material such as acrylate. In some examples, to enhance higher fiber counts, the coated optical fibers can have an outer diameter less than or equal to 200 microns.

[0121] FIGS. 61 and 62 depict a splice-on version of the multi-fiber connector 20. The splice on version has a bonding region 700 within the rear body 76, the core body 74 and the front body 72. In one example, the bonding region 700 includes bonding material (e.g., epoxy) that occupies a front portion of the rear body 76, a rear portion of the front body 72, and extends continuously through the core body 74 such that a continuous volume of bonding material extends from the front portion of the rear body 76 through the core body 74 to the rear portion of the front body 72 (see bonding region length BRL). The strength members 42 are embedded in the bonding material and bonded in the front portion of the rear body 76 and a rear portion of the core body 74. Stub optical fibers 702 are provided with front ends secured in the ferrule 46. Rear ends of the stub fibers 702 are fusion spliced (e.g., mass fusion spliced) to front ends of the cable fibers 44 at a splice location 703. The fusion splice location 703 is encapsulated in the bonding region 700 (e.g., within the bonding material forming the bonding region) at a zone positioned in front of front ends of the strength members 42. In certain examples, the portion of the bonding region for accommodating the splice extends at least 10 millimeters or at least 12 millimeters or at least 15 millimeters forwardly past the front ends of the strength members 42. In certain examples, the portion of the bonding region for accommodating the splice extends 10-20 millimeters or 12-17 millimeters forwardly past the front ends of the strength members. In certain examples, a forward portion of the bonding region that extends forwardly past the front ends of the strength members has a length that is at least 25, 30 or 35 percent of a total length of the bonding region. The bonding material can be injected into the bonding region through a port (e.g., port 29). The front of the bonding region 700 can be definedby the barrier 25 that prevents the bonding material from filling a fiber buckling region 720 that extends from the front end of the bonding region 700 to a rear end of the ferrule spring 52. In certain examples, the fiber buckling region 720 can have a length in the range of 15-25 millimeters, or in the range of 17-23 millimeters. In other examples, the fiber buckling region 720 can have a length of at least 15 millimeters, or at least 17 millimeters, or at least 19 millimeters, or at least 20 millimeters. The stub fibers 702 in the buckling region can be ribbonized or non-ribbonized (e.g., loose).

[0122] The multi-fiber splice location (e.g., fusion splice location) can be directly encapsulated by and protected by the adhesive filling the bonding region 700 (e.g., the adhesive filling the bonding region can contact the bare fibers fused together at the splice location). Alternatively, an intermediate protective structure / layer can be provided between the splice location and the adhesive filling the bonding region 700. Example intermediate protective structures can include a re-coat layer, a heat-shrink sleeve, a heat-shrink sleeve containing adhesive, a heat-shrink sleeve with a reinforcing member such as a rod, one or more films bonded across the splice location, or other structures.

[0123] The stub fibers 702 and the cable fibers 44 are arranged in a splice plane at the splice location. The splice plane is parallel to the major axis defined by the front face of the ferrule 46. The rear body 76 can be rotationally oriented relative to the multi-fiber ferrule 46 such that the strength members 42 are aligned along a plane that is perpendicular with respect to the splice plane. Portions of the cable fibers 44 extending though the bonding region 700 can be ribbonized such that the adhesive filling the bonding region 700 encapsulates an intermediate matrix layer that bonds the fibers together prior to filling the bonding region 700 with the adhesive. Alternatively, portions of the cable fibers 44 extending though the bonding region 700 can be loose prior to filling of the bonding region 700 with adhesive such that the adhesive filling the bonding region 700 encapsulates each of the fibers and bonds the fibers in place. Portions of the stub fibers 702 extending though the bonding region 700 can be ribbonized such that the adhesive filling the bonding region 700 encapsulates an intermediate matrix layer that bonds the fibers together prior to filling the bonding region 700 with the adhesive. Alternatively, portions of the stub fibers 702 extending though the bonding region 700 can be loose prior to filling of the bonding region 700with adhesive such that the adhesive filling the bonding region 700 encapsulates each of the fibers and bonds the fibers in place.

[0124] FIGS. 72-74 depict a multi-fiber optical connector 820 without a connector boot. The multi-fiber optical connector 820 utilizes many of the same components described with respect to the multi-fiber optical connector 20 and the above descriptions of such components with respect to the multi-fiber optical connector 20 also apply to the multi-fiber optical connector 820. Example components include a multi-fiber ferrule 846, optical fibers 844, a ferrule spring 852, a shape memory sleeve 848, an elastomeric seal 36, and a tum-to-engage coupler 832. In the depicted example, the coupler 832 does not engage with a connector boot. As such the coupler 832 does not include structure for attaching a connector boot (i.e., boot 34) and the coupler 832 has a reduced outer diameter or profile.

[0125] 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 without following the example examples and applications illustrated and described herein, and without departing from the true spirit and scope of the present disclosure.ASPECTS OF THE DISCLOSUREAspect 1 . A fiber optic connector comprising: a multi-fiber ferrule having an optical connection end and a fiber entrance end, the optical connection end defining a major axis and a minor axis that are perpendicular with respect to each other, the optical connection end having a major dimension that extends along the major axis and a minor dimension that extends along the minor axis, the major dimension is longer than the minor dimension, the multi-fiber ferrule having opposite major sides and opposite minor sides that extend between the optical connection end and the fiber entrance end, the major sides of the multi-fiber ferrule being separated by the minor dimension of the optical connection end and the minor sides being separated by the major dimension of the optical connection end, the multifiber ferrule having side flanges that project outwardly from the minor sides of the multi-fiber ferrule;a connector body having a front end and a rear end, the front end of the connector body defining an opening through which the multi-fiber ferrule protrudes such that the optical connection end of the multi-fiber ferrule is accessible at the front end of the connector body, the connector body defining side through-openings at opposite sides of the connector body, the side through-openings being open at an exterior of the connector body, the side flanges of the multi-fiber ferrule being received within the side through-openings; and optical fibers that extend through the connector body and into the multi-fiber ferrule through the fiber entrance end of the multi-fiber ferrule, the optical fibers having front end portions secured within the multi-fiber ferrule, the optical fibers having end faces at the optical connection end of the multi-fiber ferrule, the front end portions of the optical fibers being arranged in a row that extends along the major axis of the optical connection end of the multi-fiber ferrule.Aspect 2. The fiber optic connector of aspect 1, wherein front ends of the side through-openings are defined by rearwardly facing surfaces that are rearwardly offset from the front end of the connector body.Aspect 3. The fiber optic connector of aspects 1 or 2, wherein the rearwardly facing surfaces are configured to stop forward movement of the multi-fiber ferrule relative to the connector body via interaction with the side flanges of the multi-fiber ferrule.Aspect 4. The fiber optic connector of any one of aspects 1-3, wherein the multifiber ferrule is spring biased in a forward direction with respect to the connector body.Aspect 5. The fiber optic connector of aspect 2 or 3, wherein the connector body includes a front body having first and second opposite ends, the first end of the front body forming the front end of the connector body, wherein the front body defines the side through-openings of the connector body, wherein the front body has an open-sided configuration having at least one open side that extends from one of the rearwardly facing surfaces to the second end of the front body.Aspect 6. The fiber optic connector of any one of aspects 1-5, wherein the at least one open side includes only one open side, wherein the only one open side is defined by a main body of the front body, and wherein the front body includes a side cover that mounts to the main body to cover a rear portion of the open side, and wherein a front portion of the open side defines one of the side through-openings when the side cover is mounted to the main body.Aspect 7. The fiber optic connector of any one of aspects 1-6, wherein the side cover includes a rear spring stop for opposing a rear end of a spring that biases the multi-fiber ferrule in a forward direction relative to the connector body.Aspect 8. The fiber optic connector of any one of aspects 1-6, wherein the connector body includes a core body having a first end and an opposite second end, wherein the first end of the core body attaches to the second end of the front body such that the front body and the core body are coupled in co-axial alignment with each other along a connector axis, wherein the core body has a molded, one-piece construction, wherein the core body defines an outer circumferential groove that extends around the connector axis, and wherein the fiber optic connector includes an elastomeric seal that mounts in the circumferential groove.Aspect 9. The fiber optic connector of any one of aspects 1-8, wherein the elastomeric seal is adapted to provide radial sealing within a component to which the fiber optic connector connects.Aspect 10. The fiber optic connector of any one of aspects 1-9, wherein the component is a fiber optic adapter, a fiber optic connector interface converter or a dust cap.Aspect 11. The fiber optic connector of any one of aspects 1-8, wherein the connector body further includes a rear body having a first end and an opposite second end, wherein the first end of the rear body attaches to the second end of the core body such that the rear body and the core body are coupled in co-axial alignment with each other along the connector axis, wherein the second end of the rear body defines the rearend of the connector body, and wherein the rear body is configured for receiving a fiber optic cable.Aspect 12. The fiber optic connector of any one of aspects 1-11, further comprising a heat shrink sleeve mounted over the rear body and the fiber optic cable.Aspect 13. The fiber optic connector of any one of aspects 1-5, wherein the at least one open side includes first and second opposite open sides that extend from the rearwardly facing surfaces to the second end of the front body.Aspect 14. The fiber optic connector of any one of aspects 1-13, wherein the connector body includes a core body having a first end and an opposite second end, wherein the first end of the core body attaches to the second end of the front body via a snap-fit connection, wherein the front body and the core body are coupled in co-axial alignment with each other along a connector axis, wherein the core body has a molded, one-piece construction, wherein the core body defines an outer circumferential groove that extends around the connector axis, wherein the fiber optic connector includes an elastomeric seal that mounts in the circumferential groove, and wherein the second end of the core body defines the rear end of the connector body.Aspect 15. The fiber optic connector of any one of aspects 1-14, further comprising an inner core including a front ferrule holder having resilient latches that engage shoulders at the major sides of the multi-fiber ferrule, the front ferrule holder also defining a spring pocket in which a spring for biasing the multi-fiber ferrule in a forward direction is captured behind the ferrule, the inner core further including a rear inner core having a first end to which the front ferrule holder attaches and a second end to which a cable attaches, wherein the inner core mounts within the connector body.Aspect 16. The fiber optic connector of any one of aspects 1-15, wherein the inner core is secured within the connector body by a snap-fit connection.Aspect 17. The fiber optic connector of aspect 1, further comprising a ferrule alignment pin holder located behind the multi-fiber ferrule, the ferrule alignment pinholder having resilient latches for securing ferrule alignment pins in place with respect to the multi-fiber ferrule, wherein the resilient latches are accessible through the side through-openings to allow for release of the ferrule alignment pins.Aspect 18. The fiber optic connector of any of aspects 1-17, wherein the fiber optic connector is a hardened fiber connector and the connector body carries a seal for sealing with respect to a hardened fiber optic adapter, an interface converter, another hardened connector or a pulling cap.Aspect 19. A fiber optic connector comprising: a multi-fiber ferrule having an optical connection end and a fiber entrance end, the optical connection end defining a major axis and a minor axis that are perpendicular with respect to each other, the optical connection end having a major dimension that extends along the major axis and a minor dimension that extends along the minor axis, the major dimension is longer than the minor dimension, the multi-fiber ferrule having opposite major sides and opposite minor sides that extend between the optical connection end and the fiber entrance end, the major sides of the multi-fiber ferrule being separated by the minor dimension of the optical connection end and the minor sides being separated by the major dimension of the optical connection end; a connector body having a front end and a rear end, the front end of the connector body defining an opening through which the multi-fiber ferrule protrudes such that the optical connection end of the multi-fiber ferrule is accessible at the front end of the connector body, the connector body including a front body defining the front end of the connector body and a core body attached in co-axial alignment with the front body, the core body having a one-piece construction and being configured to define an outer circumferential groove; an elastomeric seal that mounts in the circumferential groove for sealing with respect to a hardened fiber optic adapter, an interface converter, another hardened connector or a pulling cap; and optical fibers that extend through the connector body and into the multi-fiber ferrule through the fiber entrance end of the multi-fiber ferrule, the optical fibers having front end portions secured within the multi-fiber ferrule, the optical fibers having end faces at the optical connection end of the multi-fiber ferrule, the front end portions ofthe optical fibers being arranged in a row that extends along the major axis of the optical connection end of the multi-fiber ferrule.Aspect 20. The fiber optic connector of aspect 19, wherein the front body connects to the core body by a snap-fit connection.Aspect 21. A fiber optic assembly comprising: a hardened multi-fiber connector including an environmental seal, the hardened multi-fiber connector including a multi-fiber ferrule; and an MPO converter assembly that mounts on the hardened multi-fiber connector to make the hardened multi-fiber connector compatible with a conventional nonhardened MPO adapter.Aspect 22. The fiber optic assembly of aspect 21, wherein the MPO converter assembly includes an MPO converter housing that snaps over the hardened multi-fiber connector, an MPO release sleeve and springs for biasing the MPO release sleeve in a first direction relative to the MPO converter housing.Aspect 23. The fiber optic assembly of aspects 21 or 22, wherein the MPO converter housing has primarily open major sides.Aspect 24. The fiber optic assembly of any one of aspects 21-23, wherein the MPO converter housing includes rear crossbars that engage snap features on of the hardened multi-fiber connector.Aspect 25. The fiber optic assembly of aspects 21 or 22, wherein the MPO converter housing includes a front key extender that extends a longitudinal key of the hardened multi-fiber connector.Aspect 26. The fiber optic assembly of aspects 21 or 22, wherein the MPO converter housing includes a front shroud portion that covers a portion of the multifiber ferrule that projects forwardly from a connector body of the hardened multi-fiber connector.Aspect 27. A hardened fiber optic adapter comprising: a main adapter body defining a hardened port and a non-hardened port; the main adapter body defining first and second exterior threaded portions separated by unthreaded flats; a thread supplement member including spaced-apart thread extensions that fit over the unthreaded flats, the thread extensions having exterior threads that align with the threads of the first and second exterior threaded portions to provide continuous threads about the main body.Aspect 28. The hardened fiber optic adapter of aspect 27, wherein the thread extensions are connected by a C-shaped support that fits over the main adapter body.Aspect 29. A fiber optic connector and cable assembly comprising: a cable having a jacket containing a plurality of cable optical fibers and at least one strength member; a multi-fiber ferrule having an optical connection end and a fiber entrance end, the optical connection end defining a major axis and a minor axis that are perpendicular with respect to each other, the optical connection end having a major dimension that extends along the major axis and a minor dimension that extends along the minor axis, the major dimension is longer than the minor dimension, the multi-fiber ferrule having opposite major sides and opposite minor sides that extend between the optical connection end and the fiber entrance end, the major sides of the multi-fiber ferrule being separated by the minor dimension of the optical connection end and the minor sides being separated by the major dimension of the optical connection end, the multifiber ferrule having side flanges that project outwardly from the minor sides of the multi-fiber ferrule; a connector body having a front end and a rear end, the front end of the connector body defining an opening through which the multi-fiber ferrule protrudes such that the optical connection end of the multi-fiber ferrule is accessible at the front end of the connector body, the rear end of the connector body including a bonding region containing adhesive, wherein in the strength member of the cable is bonded in the bonding region by the adhesive; andstub optical fibers that extend through the connector body and into the multifiber ferrule through the fiber entrance end of the multi-fiber ferrule, the stub optical fibers having front end portions secured within the multi-fiber ferrule, the stub optical fibers having end faces at the optical connection end of the multi-fiber ferrule, the front end portions of the stub optical fibers being arranged in a row that extends along the major axis of the optical connection end of the multi-fiber ferrule, the stub optical fibers having rear ends spliced to front ends of the cable optical fibers at an optical splice location encapsulated by the adhesive of the bonding region.Aspect 30. The fiber optic connector and cable assembly of aspect 29, wherein the optical splice location is positioned forwardly within the bonding region with respect to a forward end of the strength member, and wherein the strength member is a fiberglass reinforced polymeric rod.Aspect 31. The fiber optic connector and cable assembly of aspect 29, wherein the adhesive in the bonding region directly encapsulates the optical splice location.Aspect 32. The fiber optic connector and cable assembly of aspects 29 or 30, wherein strength member includes first and second strength members aligned along a first plane, and wherein the optical splice location defines a second plane that is perpendicular relative to the first plane.Aspect 33. The fiber optic connector and cable assembly of aspect 29, wherein the connector body includes a front body defining the front end of the connector body and a rear body defining the rear end of the connector body, wherein the connector body includes a core body positioned axially between the front body and the rear body, and wherein the bonding region extends fully through the core body and at least partially into the front body and the rear body.

Claims

What is claimed is:

1. A fiber optic connector comprising: a multi-fiber ferrule having an optical connection end and a fiber entrance end, the optical connection end defining a major axis and a minor axis that are perpendicular with respect to each other, the optical connection end having a major dimension that extends along the major axis and a minor dimension that extends along the minor axis, the major dimension is longer than the minor dimension, the multi-fiber ferrule having opposite major sides and opposite minor sides that extend between the optical connection end and the fiber entrance end, the major sides of the multi-fiber ferrule being separated by the minor dimension of the optical connection end and the minor sides being separated by the major dimension of the optical connection end, the multifiber ferrule having side flanges that project outwardly from the minor sides of the multi-fiber ferrule; a connector body having a front end and a rear end, the front end of the connector body defining an opening through which the multi-fiber ferrule protrudes such that the optical connection end of the multi-fiber ferrule is accessible at the front end of the connector body, the connector body defining side through-openings at opposite sides of the connector body, the side through-openings being open at an exterior of the connector body, the side flanges of the multi-fiber ferrule being received within the side through-openings; and optical fibers that extend through the connector body and into the multi-fiber ferrule through the fiber entrance end of the multi-fiber ferrule, the optical fibers having front end portions secured within the multi-fiber ferrule, the optical fibers having end faces at the optical connection end of the multi-fiber ferrule, the front end portions of the optical fibers being arranged in a row that extends along the major axis of the optical connection end of the multi-fiber ferrule.

2. The fiber optic connector of claim 1 , wherein front ends of the side through- openings are defined by rearwardly facing surfaces that are rearwardly offset from the front end of the connector body.

3. The fiber optic connector of claim 2, wherein the rearwardly facing surfaces are configured to stop forward movement of the multi-fiber ferrule relative to the connector body via interaction with the side flanges of the multi-fiber ferrule.

4. The fiber optic connector of claim 3, wherein the multi-fiber ferrule is spring biased in a forward direction with respect to the connector body.

5. The fiber optic connector of claim 2 or 3, wherein the connector body includes a front body having first and second opposite ends, the first end of the front body forming the front end of the connector body, wherein the front body defines the side through- openings of the connector body, wherein the front body has an open-sided configuration having at least one open side that extends from one of the rearwardly facing surfaces to the second end of the front body.

6. The fiber optic connector of claim 5, wherein the at least one open side includes only one open side, wherein the only one open side is defined by a main body of the front body, and wherein the front body includes a side cover that mounts to the main body to cover a rear portion of the open side, and wherein a front portion of the open side defines one of the side through-openings when the side cover is mounted to the main body.

7. The fiber optic connector of claim 6, wherein the side cover includes a rear spring stop for opposing a rear end of a spring that biases the multi-fiber ferrule in a forward direction relative to the connector body.

8. The fiber optic connector of claim 6, wherein the connector body includes a core body having a first end and an opposite second end, wherein the first end of the core body attaches to the second end of the front body such that the front body and the core body are coupled in co-axial alignment with each other along a connector axis, wherein the core body has a molded, one-piece construction, wherein the core body defines an outer circumferential groove that extends around the connector axis, and wherein the fiber optic connector includes an elastomeric seal that mounts in the outer circumferential groove.

9. The fiber optic connector of claim 8, wherein the elastomeric seal is adapted to provide radial sealing within a component to which the fiber optic connector connects.

10. The fiber optic connector of claim 9, wherein the component is a fiber optic adapter, a fiber optic connector interface converter or a dust cap.

11. The fiber optic connector of claim 8, wherein the connector body further includes a rear body having a first end and an opposite second end, wherein the first end of the rear body attaches to the second end of the core body such that the rear body and the core body are coupled in co-axial alignment with each other along the connector axis, wherein the second end of the rear body defines the rear end of the connector body, and wherein the rear body is configured for receiving a fiber optic cable.

12. The fiber optic connector of claim 11 , further comprising a heat shrink sleeve mounted over the rear body and the fiber optic cable.

13. The fiber optic connector of claim 5, wherein the at least one open side includes first and second opposite open sides that extend from the rearwardly facing surfaces to the second end of the front body.

14. The fiber optic connector of claim 13, wherein the connector body includes a core body having a first end and an opposite second end, wherein the first end of the core body attaches to the second end of the front body via a snap-fit connection, wherein the front body and the core body are coupled in co-axial alignment with each other along a connector axis, wherein the core body has a molded, one-piece construction, wherein the core body defines an outer circumferential groove that extends around the connector axis, wherein the fiber optic connector includes an elastomeric seal that mounts in the outer circumferential groove, and wherein the second end of the core body defines the rear end of the connector body.

15. The fiber optic connector of claim 14, further comprising an inner core including a front ferrule holder having resilient latches that engage shoulders at the major sides of the multi-fiber ferrule, the front ferrule holder also defining a spring pocket in which a spring for biasing the multi-fiber ferrule in a forward direction is captured behind the ferrule, the inner core further including a rear inner core having a first end to which the front ferrule holder attaches and a second end to which a cable attaches, wherein the inner core mounts within the connector body.

16. The fiber optic connector of claim 15, wherein the inner core is secured within the connector body by a snap-fit connection.

17. The fiber optic connector of claim 1 , further comprising a ferrule alignment pin holder located behind the multi-fiber ferrule, the ferrule alignment pin holder having resilient latches for securing ferrule alignment pins in place with respect to the multifiber ferrule, wherein the resilient latches are accessible through the side through- openings to allow for release of the ferrule alignment pins.

18. The fiber optic connector of any of claims 1-17, wherein the fiber optic connector is a hardened fiber connector and the connector body carries a seal for sealing with respect to a hardened fiber optic adapter, an interface converter, another hardened connector or a pulling cap.

19. A fiber optic connector comprising: a multi-fiber ferrule having an optical connection end and a fiber entrance end, the optical connection end defining a major axis and a minor axis that are perpendicular with respect to each other, the optical connection end having a major dimension that extends along the major axis and a minor dimension that extends along the minor axis, the major dimension is longer than the minor dimension, the multi-fiber ferrule having opposite major sides and opposite minor sides that extend between the optical connection end and the fiber entrance end, the major sides of the multi-fiber ferrule being separated by the minor dimension of the optical connection end and the minor sides being separated by the major dimension of the optical connection end;a connector body having a front end and a rear end, the front end of the connector body defining an opening through which the multi-fiber ferrule protrudes such that the optical connection end of the multi-fiber ferrule is accessible at the front end of the connector body, the connector body including a front body defining the front end of the connector body and a core body attached in co-axial alignment with the front body, the core body having a one-piece construction and being configured to define an outer circumferential groove; an elastomeric seal that mounts in the outer circumferential groove for sealing with respect to a hardened fiber optic adapter, an interface converter, another hardened connector or a pulling cap; and optical fibers that extend through the connector body and into the multi-fiber ferrule through the fiber entrance end of the multi-fiber ferrule, the optical fibers having front end portions secured within the multi-fiber ferrule, the optical fibers having end faces at the optical connection end of the multi-fiber ferrule, the front end portions of the optical fibers being arranged in a row that extends along the major axis of the optical connection end of the multi-fiber ferrule.

20. The fiber optic connector of claim 19, wherein the front body connects to the core body by a snap-fit connection.

21. A fiber optic assembly comprising: a hardened multi-fiber connector including an environmental seal, the hardened multi-fiber connector including a multi-fiber ferrule; and an MPO converter assembly that mounts on the hardened multi-fiber connector to make the hardened multi-fiber connector compatible with a conventional nonhardened MPO adapter.

22. The fiber optic assembly of claim 21 , wherein the MPO converter assembly includes an MPO converter housing that snaps over the hardened multi-fiber connector, an MPO release sleeve and springs for biasing the MPO release sleeve in a first direction relative to the MPO converter housing.

23. The fiber optic assembly of claim 22, wherein the MPO converter housing has primarily open major sides.

24. The fiber optic assembly of claim 23, wherein the MPO converter housing includes rear crossbars that engage snap features on of the hardened multi-fiber connector.

25. The fiber optic assembly of claim 22, wherein the MPO converter housing includes a front key extender that extends a longitudinal key of the hardened multi-fiber connector.

26. The fiber optic assembly of claim 22, wherein the MPO converter housing includes a front shroud portion that covers a portion of the multi-fiber ferrule that projects forwardly from a connector body of the hardened multi-fiber connector.

27. A hardened fiber optic adapter comprising: a main adapter body defining a hardened port and a non-hardened port; the main adapter body defining first and second exterior threaded portions separated by unthreaded flats; a thread supplement member including spaced-apart thread extensions that fit over the unthreaded flats, the thread extensions having exterior threads that align with the threads of the first and second exterior threaded portions to provide continuous threads about the main adapter body.

28. The hardened fiber optic adapter of claim 27, wherein the thread extensions are connected by a C-shaped support that fits over the main adapter body.

29. A fiber optic connector and cable assembly comprising: a cable having a jacket containing a plurality of cable optical fibers and at least one strength member; a multi-fiber ferrule having an optical connection end and a fiber entrance end, the optical connection end defining a major axis and a minor axis that are perpendicular with respect to each other, the optical connection end having a major dimension thatextends along the major axis and a minor dimension that extends along the minor axis, the major dimension is longer than the minor dimension, the multi-fiber ferrule having opposite major sides and opposite minor sides that extend between the optical connection end and the fiber entrance end, the major sides of the multi-fiber ferrule being separated by the minor dimension of the optical connection end and the minor sides being separated by the major dimension of the optical connection end, the multifiber ferrule having side flanges that project outwardly from the minor sides of the multi-fiber ferrule; a connector body having a front end and a rear end, the front end of the connector body defining an opening through which the multi-fiber ferrule protrudes such that the optical connection end of the multi-fiber ferrule is accessible at the front end of the connector body, the rear end of the connector body including a bonding region containing adhesive, wherein in the strength member of the cable is bonded in the bonding region by the adhesive; and stub optical fibers that extend through the connector body and into the multifiber ferrule through the fiber entrance end of the multi-fiber ferrule, the stub optical fibers having front end portions secured within the multi-fiber ferrule, the stub optical fibers having end faces at the optical connection end of the multi-fiber ferrule, the front end portions of the stub optical fibers being arranged in a row that extends along the major axis of the optical connection end of the multi-fiber ferrule, the stub optical fibers having rear ends spliced to front ends of the cable optical fibers at an optical splice location encapsulated by the adhesive of the bonding region.

30. The fiber optic connector and cable assembly of claim 29, wherein the optical splice location is positioned forwardly within the bonding region with respect to a forward end of the strength member, and wherein the strength member is a fiberglass reinforced polymeric rod.

31. The fiber optic connector and cable assembly of claim 29, wherein the adhesive in the bonding region directly encapsulates the optical splice location.

32. The fiber optic connector and cable assembly of claim 29 or 30, wherein strength member includes first and second strength members aligned along a first plane,and wherein the optical splice location defines a second plane that is perpendicular relative to the first plane.

33. The fiber optic connector and cable assembly of claim 29, wherein the connector body includes a front body defining the front end of the connector body and a rear body defining the rear end of the connector body, wherein the connector body includes a core body positioned axially between the front body and the rear body, and wherein the bonding region extends fully through the core body and at least partially into the front body and the rear body.

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