Patent Publication Number: US-2023152533-A1

Title: Compact fiber optic connectors, cable assemblies and methods of making the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 17/704,231 filed Mar. 25, 2022, which is a continuation of U.S. application Ser. No. 16/695,025 filed on Nov. 25, 2019, which claims the benefit of priority to International Application No. PCT/US2017/064027 filed Nov. 30, 2017, which claims the benefit of U.S. Application No. 62/526,011, filed on Jun. 28, 2017, U.S. Application No. 62/526,018, filed on Jun. 28, 2017, and U.S. Application No. 62/526,195, filed on Jun. 28, 2017, the content of which is relied upon and incorporated herein by reference in entirety. 
    
    
     BACKGROUND 
     The disclosure is directed to fiber optic connectors along with methods for making fiber optic connectors. More specifically, the disclosure is directed to fiber optic connectors having improved or simplified designs along with methods of making. 
     Optical fiber is increasingly being used for a variety of applications, including but not limited to broadband voice, video, and data transmission. As bandwidth demands increase optical fiber is migrating toward subscribers in outdoor communication networks such as in fiber to the premises applications such as FTTx and the like. To address this need for making optical connections in communication networks for outdoor environments hardened fiber optic connectors were developed. One of the most commercially successful hardened fiber optic connector is the OptiTap® connector sold by Corning Optical Communications LLC of Hickory, N.C., such as disclosed in U.S. Pat. Nos. 7,090,406 and 7,113,679 (the &#39;406 and &#39;679 patents). The OptiTap® connector is a hardened male plug connector for terminating a fiber optic cable and the assembly is configured for optical connection such as with a complementary receptacle. As used herein, the term “hardened” describes a connector or receptacle port intended for making an environmentally sealed optical connection suitable for outdoor use, and the term “non-hardened” describes a connector or receptacle port that is not intended for making an environmentally sealed optical connection such as the well-known SC connector. 
       FIGS.  1 A- 1 C  are prior art depictions showing various stages of mating of a preconnectorized cable  1  having a plug connector  5  such as an OptiTap® connector with a receptacle  3 . Receptacle  3  mates plug connector  5  with a standard SC connector (i.e., a non-hardened connector) at a second end (not visible in these views) using an adapter sleeve for aligning ferrules when mating plug connector  5  with the a non-hardened connector. Protection of the non-hardened connector side of the receptacle is typically accomplished by mounting the receptacle  3  through a wall of an enclosure or the like so that the non-hardened end of the receptacle is disposed inside the enclosure for environmental protection of the non-hardened connector. As shown by  FIGS.  1 A- 1 C , the other end of the receptacle  3  is accessible for receiving the plug connector  5  at the wall of the enclosure. Other applications may mount the receptacle  3  inside an enclosure on a bracket or the like. 
     Receptacle  3  allows an optical connection between the hardened connector such as the OptiTap® male plug connector with a non-hardened connector such as the SC connector at nodes in the optical network that typically transition from an outdoor space to an enclosed and protected space. Receptacle  3  is described in further detail in U.S. Pat. No. 6,579,014. Receptacle  3  includes a receptacle housing and an adapter sleeve disposed therein. The receptacle  3  receives a non-hardened connector at a second end as represented by the arrow pointing to the left. The receptacle  3  typically requires mounting through a wall of a closure, or inside the closure, such as a closure mounted on the side of subscribers premises, disposed in an underground vault or on a pole for protecting the non-hardened connector for outside plant deployments. 
     Network operators face many challenges for building, deploying and connecting subscribers to outside plant communication networks such as Fiber-to-the-Home (FTTH) or Fiber-to-the-location (FTTx) networks. Besides right of way access for the communication networks, network operators may have limited space to available on existing poles or in existing vaults for mounting devices. Initially, conventional hardened fiber optic connectors were typically mounted on robust and relatively stiff fiber optic cables, and slack storage for these fiber optic cables may also consume limited space or become unsightly in aerial deployments. Further as outside plant deployments evolved many network operators desired to route the fiber optic cable assembly with the connector through an existing wall of a subscriber premises and into the building or route the fiber optic cable assembly with the connector through a buried duct. Thus, network operators because sensitive to the size of the fiber optic connector for these types of deployment applications. 
     Consequently, there exists an unresolved need for fiber optic connectors that allow quickly and easy deployment and connectivity in a simple and efficient manner while still being cost-effective. 
     SUMMARY 
     The disclosure is directed to fiber optic connectors and methods of making fiber optic connectors as described and recited in the claim. The concepts disclosed allow a compact form-factor for an optical fiber connector suitable for numerous applications and variations as desired. 
     One aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule holder, and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a round cross-section and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion, where the transition region comprises a asymmetric portion. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule, where the ferrule is disposed within a portion of the ferrule holder. 
     Another aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule holder, and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a round cross-section and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion, where the transition region comprises a asymmetric portion, where the rear portion comprises a keying portion. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule, where the ferrule is disposed within a portion of the ferrule holder. 
     Still another aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule holder, and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a round cross-section and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion, where the transition region comprises a threaded portion. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule, where the ferrule is disposed within a portion of the ferrule holder. 
     Yet another aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule holder, and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a round cross-section and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion, where the transition region comprises a threaded portion, and the rear portion comprises a keying portion, where the keying portion extends into the transition region. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule, where the ferrule is disposed within a portion of the ferrule holder. 
     A further aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule holder, and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a round cross-section and at least one locking feature, and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion, where the transition region comprises an asymmetric portion. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule, where the ferrule is disposed within a portion of the ferrule holder. 
     A still further aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule holder, and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a round cross-section and at least one locking feature is integrally formed in the rear portion of the housing, and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion, where the transition region comprises an asymmetric portion, and the rear portion comprises a keying portion. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule, where the ferrule is disposed within a portion of the ferrule holder. 
     Another aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule holder, and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a round cross-section and at least one locking feature is integrally formed in the rear portion of the housing, and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion, where the transition region comprises a threaded portion. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule, where the ferrule is disposed within a portion of the ferrule holder. 
     Yet another aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule holder, and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a round cross-section and at least one locking feature is integrally formed in the rear portion of the housing, and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion, where the transition region comprises a threaded portion, and the rear portion comprises a keying portion, where the keying portion extends into the transition region. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule, where the ferrule is disposed within a portion of the ferrule holder. 
     One aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule holder, and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a round cross-section and at least one locking feature is a ramp with a ledge that is integrally formed in the rear portion of the housing, and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion, where the transition region comprises a threaded portion, and the rear portion comprises a keying portion, where the keying portion extends into the transition region. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule, where the ferrule is disposed within a portion of the ferrule holder. 
     Yet another aspect of the disclosure is directed to a fiber optic connector comprising a housing and a ferrule. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end, where a part of a rear portion of the housing comprises a polygonal cross-section, and a part of the front portion of the housing comprises a non-round cross-section with a transition region disposed between the rear portion and the front portion. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule. 
     Another aspect of the disclosure is directed to a fiber optic connector comprising a housing, a ferrule, a cable adapter, a boot and a sealing element. The housing comprises a rear end and a front end with a longitudinal passageway extending from the rear end to the front end. The ferrule comprising a fiber bore extending from a rear end to a front end of the ferrule. The boot is attached to a portion of the cable adapter, and a sealing element is disposed over a portion of the boot and a rear portion of the housing. 
     Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the same as described herein, including the detailed description that follows, the claims, as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description present embodiments that are intended to provide an overview or framework for understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments and together with the description serve to explain the principles and operation. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIGS.  1 A- 1 C  are prior art depictions showing various stages of mating of a prior art preconnectorized cable having a conventional hardened plug connector with a receptacle; 
         FIG.  2    is a perspective view of a fiber optic cable assembly having a fiber optic connector with a housing according to one aspect of the disclosure; 
         FIG.  2 A  is a perspective view of another fiber optic cable assembly having a fiber optic connector with alternative housing according to one aspect of the disclosure; 
         FIG.  3    is an exploded view of the fiber optic cable assembly of  FIG.  2   ; 
         FIG.  4    is a close-up perspective view of a fiber optic connector having a housing that is similar to the housing of  FIG.  2    and depicting geometric features of the housing according to one aspect of the disclosure; 
         FIGS.  4 A- 4 D  are respective cross-sectional views of the housing of  FIG.  4    taken along respective planes defined by lines  4 A- 4 A, line  4 B- 4 B, line  4 C- 4 C and line  4 D- 4 D; 
         FIG.  4 E  is a side view of an explanatory housing that is similar to housing shown in the fiber optic connector  FIG.  4    and further include threads that are discontinuous on the front portion; 
         FIG.  5    is an exploded view of a ferrule subassembly of the fiber optic connector of  FIG.  3   ; 
         FIGS.  6  and  7    are longitudinal sectional views of the ferrule subassembly cable assembly of  FIG.  3   ; 
         FIG.  8    is a perspective view of the ferrule carrier of the ferrule subassembly of  FIG.  3   ; 
         FIG.  9    is a close-up perspective view of the front end of the ferrule carrier of  FIG.  8   ; 
         FIG.  10    is a perspective view of an alternative ferrule carrier that may be used with the ferrule subassemblies disclosed herein; 
         FIGS.  11  and  12    respectively are a partially exploded view and an assembled view of the alternative ferrule carrier depicted in  FIG.  10   ; 
         FIGS.  13  and  14    respectively are a partial sectional view and a cross-sectional view of the alternative ferrule carrier of  FIGS.  10 - 12    depicted assembled in a housing of a fiber optic connector; 
         FIGS.  15  and  16    are longitudinal sectional views of the fiber optic cable assembly of  FIG.  2    showing details of the construction; 
         FIG.  17    is an exploded view of another fiber optic cable assembly that is similar to the fiber optic cable assembly of  FIG.  2    with a fiber optic connector having a different ferrule subassembly; 
         FIG.  18    is a partially exploded view of the fiber optic cable assembly of  FIG.  17    with the fiber optic cable attached to the ferrule subassembly; 
         FIG.  19    is a perspective view of another cable assembly having a different fiber optic connector with a housing that is similar to the housing shown with the fiber optic connector of  FIG.  2    according to another aspect of the disclosure; 
         FIG.  20    is a close-up perspective view of the fiber optic connector of  FIG.  19    depicting geometric features of the housing; 
         FIG.  21    is an exploded view of another fiber optic cable assembly similar to that of  FIG.  19    with a fiber optic connector having a housing having threads that are discontinuous according to another aspect of the disclosure; 
         FIG.  22    is an perspective assembled view of the fiber optic cable assembly of  FIG.  21   ; 
         FIG.  23    is a perspective view of the cable assembly of  FIG.  22    with a dust cap installed on the fiber optic connector; 
         FIG.  24    is a longitudinal sectional view of the cable assembly of  FIG.  22    in a vertical direction; 
         FIG.  25    is a detailed exploded view of the front end and of the fiber optic connector of  FIG.  22   ; 
         FIG.  26    is a cross-sectional view taken at an opening of the housing and showing a transverse ferrule retention member securing the ferrule of the fiber optic connector of  FIG.  22   ; 
         FIGS.  27  and  28    respectively are a detail view of an alternative transverse ferrule retention member and cross-sectional view showing the alternative transverse ferrule retention member for securing the ferrule; 
         FIG.  29    is a longitudinal sectional view of a front portion of the fiber optic connector of  FIG.  22    in a horizontal direction; 
         FIG.  30    is a front end sectional view of a housing having a tuning pocket that allows rotational tuning of the ferrule during manufacture for improving optical performance; 
         FIGS.  31  and  32    depict explanatory ferrules having at least one selectively tunable surface; 
         FIGS.  33 - 36    are various views of depicting the housing of the fiber optic connector of  FIG.  23   ; 
         FIG.  37    is a perspective view of another fiber optic cable assembly with still another alternative fiber optic connector having a nosepiece; 
         FIG.  38    is a perspective view of the fiber optic cable assembly of  FIG.  37    showing a sectional view of a dust cap having a pulling eye and that may be secured to the threads disposed on the housing; 
         FIG.  39    is an exploded view of the cable assembly of  FIG.  37   ; 
         FIG.  40    is a front end sectional view of the fiber optic connector of  FIG.  37    showing the nosepiece attached to the front end of the housing; 
         FIG.  41    is a front end view of the housing of  FIG.  37    showing a securing surface such as a weld interface on the housing so that the nosepiece may be attached to the housing so that it covers an opening for the transverse ferrule retention member; 
         FIGS.  42  and  43    are perspective and side views of a fiber optic connector similar to  FIG.  37    having an alternative housing with a keying feature for fiber optic connectors; 
         FIGS.  44  and  45    are perspective views of alternative housings depicting other locking feature designs for use with the fiber optic connectors disclosed; 
         FIG.  46    is a perspective view of still another fiber optic cable assembly having a cable adapter that fits into a rear opening of a housing that can be changed for different types of fiber optic cables; 
         FIGS.  47  and  48    respectively are a perspective view and a cross-sectional view the cable adapter of  FIG.  46   ; 
         FIGS.  47 A and  48 A  respectively are a perspective view and a cross-sectional view of another cable adapter; 
         FIG.  49    is a sectional view of the rear portion of an explanatory fiber optic cable assembly showing the fiber optic cable within the cable adapter taken in a vertical direction to depict how the cable may be attached to the fiber optic connectors disclosed herein; 
         FIG.  50    is a sectional view of the rear portion of the cable assembly of  FIG.  46    showing the fiber optic cable within the cable adapter taken in a horizontal direction; 
         FIGS.  51 - 54    are various views of another fiber optic cable assembly having a keying portion configured as a female key;  FIG.  51 A- 53 A  are various views of a portion of another fiber optic cable assembly having a cable adapter with flexures for cable bend-strain relief; 
         FIG.  54 A  is a front perspective view of another housing that may be used with the fiber optic connector concepts disclosed herein; 
         FIG.  55    depicts a distribution cable having a fiber optic connector according to the concepts disclosed disposed on a tether; 
         FIG.  56    is a perspective view of an explanatory fiber optic connector that further comprise a conversion housing attached about the housing for changing the fiber optic connector from a first connector footprint to a second connector footprint; 
         FIG.  57    is a sectional view of the fiber optic connector of  FIG.  56   ; 
         FIG.  58    is a partially exploded view of an explanatory fiber optic connector showing the fiber optic connector with a first connector footprint along with a conversion housing for changing the fiber optic connector to a second connector footprint that is a hardened connector footprint; 
         FIG.  59    is an assembled view of the fiber optic connector of  FIG.  58    showing the second connector footprint as a hardened connector footprint with the dust cap removed for clarity; 
         FIG.  60    is an assembled view of the fiber optic connector of  FIG.  58    showing the second connector footprint with the dust cap installed; 
         FIG.  61    is a sectional view of the fiber optic connector of  FIG.  60   . 
         FIG.  62    is a perspective view of an explanatory fiber optic connector that may have a conversion housing attached about the housing for changing the fiber optic connector from a first connector footprint to a second connector footprint; 
         FIG.  63    is an assembled view of the fiber optic connector of  FIG.  62    after conversion to a second connector footprint configured as a hardened connector footprint with the dust cap removed for clarity; 
         FIG.  64    is a partially exploded view of the fiber optic connector of  FIG.  63   ; 
         FIG.  65    is a sectional view of the conversion housing and coupling nut of the fiber optic connector of  FIG.  63   ; 
         FIGS.  66  and  67    are sectional views of the fiber optic connector of  FIG.  63   ; 
         FIGS.  68  and  69    are perspective views of the retaining member of the fiber optic connector of  FIG.  63   ; 
         FIGS.  70  and  71    respectively are perspective and sectional views of another connector having a ferrule disposed within a ferrule holder that is loaded from the front end of the connector  10  and having a SC housing attached; 
         FIGS.  72  and  72 A  respectively are top and bottom perspective views of the connector housing of  FIGS.  70  and  71   ; 
         FIGS.  73  and  74    are cross-sectional views of the housing of the connector of  FIGS.  70  and  71   ; 
         FIG.  75    is a partially exploded view of the front end of the connector depicted in  FIGS.  70  and  71   ; 
         FIG.  76    is a cross-sectional view of the front end of the connector depicted in  FIGS.  70  and  71   ; 
         FIG.  77    is a perspective view of the ferrule and ferrule holder of the connector depicted in  FIGS.  70  and  71   ; and 
         FIG.  78    is a front end view of the connector depicted in  FIGS.  70  and  71    without the SC housing showing the details for the retention of the ferule holder assembly; and 
         FIGS.  79  and  79 A  respectively are a perspective view and a cross-sectional view of another connector housing comprising a non-round rear portion. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, like reference numbers will be used to refer to like components or parts. 
     The concepts disclosed advantageously provide fiber optic connectors that allow streamlined manufacture and assembly along with easy and intuitive connectivity with other devices while still having a compact footprint. The fiber optic connectors disclosed are explained and depicted with several different embodiments and various other alternative components or optional features that may be incorporated into one or more of the fiber optic connector concepts as desired. By way of explanation, several different variations of housings are disclosed that can be modified to use with connector constructions where the ferrule loads from either the rear end of the housing or the ferrule load from the front end of the housing. Some embodiments may advantageously use fewer parts while providing robust and reliable optical performance. For instance, some of the embodiments disclosed may have the ferrule cooperate directly with an housing (e.g., assembled) without using a ferrule holder like conventional fiber optic connectors. Other constructions may increase the part count of the connectors for various reasons or could use a ferrule holder if desired. 
     In one aspect the fiber optic connectors (hereinafter “connector”) disclosed advantageously comprise a housing and a ferrule. The housing provides a first connector footprint that interfaces with other devices for making an optical connection and various different first connector footprints are disclosed herein that may be used with the connector constructions disclosed. The first connector footprints may be defined by a housings having a rear portion (RP) and a front portion (FP). First connector footprints may also be further defined by a transition region (TR) disposed between the rear portion (RP) and the front portion (FP) of the housing. 
     In one explanatory example, the housing comprises a part of the rear portion (RP) having a round cross-section (RCS) and a part of the front portion having a non-round cross-section (NRCS). The front portion (FP) or the rear portion (RP) of the housing may be further defined in various configurations as disclosed herein while retaining a part of the rear portion (RP) with the round cross-section (RCS) and a part of the front portion (FP) having a non-round cross-section (NRCS). By way of explanation, the front portion (FP) may have a rectangular cross-section that provides a first orientation feature for the connectors for alignment during mating and inhibit insertion into a non-compliant device or port. 
     However, other variations of housings according to the concepts disclosed are possible. As an example of another housing disclosed herein for use with the connector constructions disclosed, the housing may be defined as comprising a part of the rear portion (RP) having a polygonal cross-section (PCS) and a part of the front portion having a non-round cross-section (NRCS). The front portion (FP) or the rear portion (RP) of this explanatory housing may be further defined in various configurations as disclosed herein while retaining a part of the rear portion (RP) with the polygonal cross-section (PCS) and a part of the front portion (FP) having a non-round cross-section (NRCS) such as shown in  FIGS.  79  and  79 A . By way of example, the polygonal cross-section (PCS) may be a hexagon, a rectangle, a square or other suitable polygon as desired. 
     Housings disclosed herein define the mating interface for a complimentary device suitable for mating with the connector and the connector footprints disclosed are useful for inhibiting insertion into a non-compliant port or device and damaging either the connector or the device along with assuring a suitable optical operation for the optical connection since the connector and device are matched. Moreover, the housings may have features that aid in the proper alignment or orientation of the connector with the complimentary device such as markings, keys, keyways, etc. without significantly changing the primitive form-factors of the housings that are disclosed and claimed herein. By way of example, even though a round cross-section may include another feature such as a key or a keyway it is still considered to be a round cross-section. Additionally, housing may have other features such as locking features for securing the optical mating with a complimentary device or threads for securing a dust cap. 
     The housing footprints disclosed herein may be further defined by other geometry of the housing(s). By way of example, the transition region (TR) disposed between the rear portion (RP) and the front portion (FP). The transition region (TR) may have different configurations according to the concepts disclosed. In one embodiment, the transition region (TR) may comprise a first transition portion (TP 1 ) disposed on a first side of the housing and a second transition portion (TP 2 ) disposed on a second side of the housing. The first transition portion (TP 1 ) and the second transition portion (TP 2 ) may be spaced apart by an offset distance (OD) in the longitudinal direction. However, other embodiments of housings disclosed herein may have all of the transition portions of the transition region (TR) aligned along a common transverse plane of the connector as desired. In still other embodiments, the transition region (TR) of the housing may comprise a threaded portion (TP). 
     Other variations may further define the housing footprints disclosed herein. By way of example and explanation for use with appropriate housings disclosed, the first transition portion (TP 1 ) comprises a first riser dimension (FRD) from the non-round cross-section (NRCS) to the round cross-section (RCS), and the second transition portion (TP 2 ) comprises a second riser dimension (SRD) from the non-round cross-section (NRCS) to the round cross-section (RCS), where the first riser dimension (FRD) is different that the second riser dimension (SRD). 
     By way of another example of non-round cross-section (NRCS) for use with appropriate housings disclosed herein, a part of the front portion (FP) of the housing having the non-round cross-section (NRCS) comprises a rectangular cross-section having rounded corners (RC). The rectangular cross-section with rounded corners (RC) is a non-round cross-section (NRCS) due to the rectangular cross-section. The rounded corners (RC) may be sized so they have a similar outer dimension (OD) as a dimension (D) for the round cross-section (RCS) or not. The rounded corners (RC) may provide stability and snug fit for the mated connector within a port or device when side-pull forces are experienced to inhibit undue optical attenuation by having the round corners transition between the front portion (FP) to the rear portion (RP). However, other geometry is possible such as chamfers or the like such as when the rear portion (RP) has a polygon cross-section (PCS). 
     The housing footprints disclosed herein may be still further defined by other geometry of the housing(s). For instance, the front portion (FP) of the housing may comprise another cross-section portion (ACSP). By way of explanation, the another cross-sectional portion (ACSP) may comprise a SC footprint. The SC footprint can, in part, be similar to the inner housing of a conventional SC connector. This particular housing footprint is useful for allowing the connectors disclosed to be backwards compatible into existing devices or ports using well-established connector footprints as desired. 
     Housings may also define further features such as a transition region disposed between the rear portion and the front portion with the transition region comprising an asymmetric transition with respect to a longitudinal axis of the housing. Likewise, other features on the housing may define the housing as asymmetric for orientation or mating with compliant devices or ports. 
     Another aspect for some of the advantageous connectors disclosed herein comprise one or more features allowing for rotation of the ferrule during assembly for tuning the connector and improving optical performance. Some of the connector designs disclosed also offer multi-stage tuning of the ferrule/assembly or infinite tuning of the ferrule/assembly to any desired rotational position for improving optical performance. 
     The concepts described herein are suitable for making both indoor and outdoor fiber optic cable assemblies using the connectors disclosed such as drop or distribution cables. Further, the fiber optic connectors disclosed may allow for the use of one or more additional components for changing the connector form-factor defined by the particular housing. By way of example, a conversion housing may cooperate with the housing of the connector for changing the fiber optic connector from the first connector footprint defined by the housing to a second connector footprint at least partially defined by the conversion housing. Consequently, the connectors disclosed herein may be converted to be compatible as other well-known commercial connectors for Fiber-to-the-Home applications such as an SC connector or an OptiTap® connector such as available from Corning Optical Communications of Hickory, N.C. Of course the concepts disclosed herein may be used with other fiber optic connector types whether hardened or not and are not limited to these particular connector conversions. Likewise, the connector designs disclosed may be hybrid designs with both optical and electrical connectivity. Electrical connectivity may be provided by contacts on or in a portion of the housing of the connector and may be useful for power or data as desired for applications such as FTTx, 5G networks, industrial applications or the like. These and other additional concepts are discussed and disclosed in illustrative detail with reference to FIGS. herein. 
     Several different constructions of fiber optic cable assemblies  100  (hereinafter “cable assemblies”) comprising connector  10  and variations of connector  10  are disclosed herein. The connectors  10  may use any of the suitable housings or different connector constructions as desired and appropriate. By way of explanation,  FIGS.  2 ,  2 A,  3  and  5 - 17    disclose connectors where a ferrule  30  is inserted from a rear end  21  of housing  20 , and  FIGS.  19 - 43    and  FIGS.  46 - 53    disclose connectors where ferrule  30  is inserted from a front end  23  of the connector  10 . However, housings  20  may be modified for using connector designs.  FIGS.  4 A- 4 E  depict an explanatory housing  20  for discussing geometry that generally speaking may be used with any appropriate connector construction as well as have the housing modified or altered for the desired housing design or connector construction. Likewise, housing  20  of  FIG.  2 A  with the threaded transition portion (TP) may be modified or altered for the desired housing design or connector construction.  FIGS.  44  and  45    disclose concepts related to alternative locking features  20 L for use with housings  20  as appropriate.  FIGS.  46 - 53    disclose another cable assembly  100  comprising connector  10  concepts disclosing another cable adapter that may be used with appropriate connectors  10  disclosed herein.  FIG.  54    depicts connector  10  according to the concepts disclosed having another housing footprint.  FIGS.  56 - 61    disclose cable assemblies  100  comprising connectors  10  having a first connector footprint where the connectors  10  may be convertible to connectors  10 ′ having a second connector footprint using a conversion housing  80 ,  82 .  FIGS.  62 - 69    disclose cable assemblies  100  comprising connectors  10  having a first connector footprint where the connectors  10  may be convertible to connectors  100 ″ having a second connector footprint using a different conversion housing  82 .  FIGS.  70 - 78    disclose a connectors where ferrule  30  is disposed within a ferrule holder  49  and inserted from a front end  23  of the connector  10 . 
       FIG.  2    is a perspective view and  FIG.  3    is an exploded view of cable assembly  100  having connector  10  and a fiber optic cable  90  (hereinafter “cable”).  FIGS.  15  and  16    are longitudinal sectional views of the cable assembly  100  of  FIG.  2    showing details of the construction.  FIG.  2 A  depicts cable assembly  100  having connector  10  with a housing  20  that is similar to the housing  20  for connector  10  of  FIG.  2   , but the housing  20  of  FIG.  2 A  has a different transition region TR. Specifically, the housing  20  of  FIG.  2 A  has a transition region TR with a threaded portion TP and may be used with the connector constructions disclosed herein as appropriate. 
     Connector  10  comprises housing  20  and a ferrule  30 . Housing  20  comprises a rear end  21  and a front end  23  with a longitudinal passageway  22  extending from the rear end  21  to the front end  23 . As best shown in  FIG.  7   , ferrule  30  comprises a fiber bore  32  extending from a rear end  31  to a front end  33 . Passageway  22  allows one or more optical fibers of cable  90  to pass through the housing  20  for insertion into fiber bore  32  of ferrule  30  such as depicted in  FIG.  7   . Cable  90  comprises at least one optical fiber  92 , one or more strength components  94  and a cable jacket  98 . 
     Connector  10  or components of connector  10  as depicted in  FIGS.  2 ,  2 A,  3  and  5 - 17    allows ferrule  30  to be inserted into housing  20  from rear end  21  of housing  20 . Specifically, ferrule  30  is inserted into an opening  21 A at the rear end  21  of housing  20 . Housing  20  depicted in  FIG.  2 A  is similar to the housing  20   FIG.  2   , except it has a different transition region (TR). Specifically, the transition region (TR) of the housing  20  of  FIG.  2 A  comprises a threaded portion; otherwise the concepts of the connector are similar to the other disclosed herein. The thread portion (TR) allows the securing of an appropriate dust cap  70  and also allows for the conversion of the connector footprint such as to a hardened connector footprint such as shown in  FIGS.  62 - 69   . However, the concepts of the rear inserted connector constructions may be used with any suitable housing disclosed herein. 
     As depicted, connector  10  of  FIG.  3    comprises housing  20 , ferrule sub-assembly  60  and cable adapter  59 . In this embodiment, ferrule  30  is a portion of ferrule sub-assembly  60 . An opening  21 A at the rear end  21  of housing  20  is sized for receiving a portion of ferule sub-assembly  60 . Ferrule sub-assembly  60  is configured to cooperate with the housing  20  for inhibiting the rotation of the ferrule sub-assembly  60  with respect to housing  20  when assembled. However, ferrule sub-assembly  60  may be configured to allow rotation of ferrule  30  for tuning as represented by arrows and angle θ as desired before the ferrule sub-assembly  60  is fully-seated within housing  20  as discussed herein. 
     Ferrule sub-assembly  60  also comprises a ferrule carrier  40 . Ferrule carrier  40  may have different configurations as disclosed herein. Ferrule  30  is tunable relative to housing  20  if desired and may have step-tuning in defined increments based on the ferrule geometry. However, other features or designs disclosed herein for the connectors may allow infinite tuning of the ferrule to any desired rotation position. Tuning ferrule  30  allows improved optical performance by turning the ferrule so that any eccentricity in the optical fiber, ferrule or connector is rotated to a known rotational position or quadrant in a uniform manner. Consequently, connectors or other mating devices can be tuned to similar relative rotational positions for improving optical performance such as reducing optical insertion loss of due to optical fiber core misalignment or the like as understood in the art. Embodiments disclosed herein may also have a plurality of interfaces between components for tuning of the connector as desired. 
     The design of connector  10  of  FIG.  3    may also advantageously allow multi-stage tuning if desired. Ferrule  30  or other components/assemblies may be tunable in step increments such as by quadrants or be infinitely tuned as desired. By way of example, ferrule sub-assembly  60  may be may be configured to allow rotation of the sub-assembly with respect to cable adapter  59  (or other components) as desired for tuning ferrule  30  as represented by the arrows and angle ϕ as depicted. Moreover, multi-stage tuning may result in infinite tuning, which means that any desired rotational position desired for any eccentricity of the fiber core within the ferrule  30  is possible. The step or degree of tuning at different component interfaces may depend on the particular construction of the ferrule, ferrule carrier, cable adapter or housing with respect to the permitted of rotation and the possible increments of rotation for the components. 
     By way of example, a first-stage of tuning may be step-tuning by quadrant and a second-stage of tuning may be infinite tuning to allow infinite rotation as desired. More specifically, the first-stage step-tuning may be used for gross tuning of the eccentricity of the fiber core such as to the desired quadrant of the and then the second-stage provides infinite tuning by allowing the fine tuning of the eccentricity of the fiber core within the quadrant for precise rotational positioning. By way of explanation, infinite tuning may accomplished by having one or more components rotate through an angle of ±180 degrees without step increments, thereby allowing any rotational position for ferrule  30 . Of course, other tuning schemes are possible using the concepts disclosed herein. Likewise, variations of ferrule carrier  40  or ferrule subassembly  60  are possible and disclosed herein for use with any suitable housing  20 . 
     Connector  10  of  FIG.  3    allows ferrule  30  to be rotated or tuned within the ferrule subassembly  60  as depicted. Ferrule  30  may be configured to rotate as a step rotation or infinite rotation depending on the particular design. For instance, ferrule  30  could have a selectively tunable surface  36  that is round for providing infinite rotational positioning or selectively tunable surface of ferrule  30  could comprise a plurality of planar surfaces  36  for step tuning by only allowing certain rotation positions. Moreover, infinite tuning of ferrule  30  may be accomplished by tuning or rotating though an angle of ±180 relative to the ferrule carrier  40  if desired. Being able to rotate one or more components in either direction allows for flexibility in tuning and inhibits excessive twisting of the optical fiber, which is generally undesirable. 
     Connector  10  of  FIG.  3    also allows ferrule carrier  40  to be rotated for tuning the ferrule relative to housing  20  as depicted. In this embodiment, ferrule carrier  40  is tunable relative to the housing  20  by way of the rotational position of ferrule carrier  40  relative to cable adapter  59  or rotational position of the cable adapter  59  with respect to the housing. Specifically, ferrule carrier  40  may be tunable though an angle ϕ of ±180 relative to the housing  40  or in step-increments such as using ferrule carrier rotational key  41 K ( FIG.  5   ) or the like as desired. For instance, a ferrule carrier rear end  41  may have one or more keys for cooperating with cable adapter  59  and only allowing certain positions for tuning, or the ferrule carrier rear end  41  may simply cooperate with the cable adapter  59  for providing infinite rotational positions for tuning. The details of tuning will be discussed in more detail below. 
     Likewise, it is possible for connector  10  of  FIG.  3    to have to a third interface for tuning. Specifically, the cable adapter  59  may be tunable relative to the rear end  21  of housing  20 . Like the ferrule carrier rear end  41 , a flange portion (not numbered) of cable adapter  59  may have one or more keys for cooperating with the rear end  21  of housing  20  and only allowing certain positions for tuning, or the flange portion of cable adapter  59  may simply cooperate with the rear end  21  of housing  20  for providing infinite rotational positions for tuning. Thus, connector  10  of  FIG.  3    provides several different tuning options for manufacturing depending on the desired requirements for the connector. 
       FIGS.  4 - 4 E  depict an explanatory housing  20  for connectors and will be described in further detail to explain concepts and geometry of housings  20  suitable for use with connector concepts disclosed herein. Although the housing of  FIG.  4    is a close-up perspective view of connector  10  having a different construction than the housing  20  depicted in  FIGS.  2  and  3   , the housing  20  of  FIG.  4    is similar to housing  20  of the connector of  FIGS.  2  and  3   . Generally speaking, the footprint of housing  20  of  FIG.  4    may be used with connector constructions that insert the ferrule  30  from the rear end  21  of housing  20  or connector constructions that insert the ferrule  30  from the front end  23  of housing with appropriate modification(s) for the connector construction. By way of explanation, the longitudinal passageway  22  of the housing  20  may need to be modified for the different connector constructions as appropriate. 
     Connectors  10  disclosed herein may use any suitable housing  20  with the desired footprint or construction. The disclosure describes several different housings that may be used with connector constructions as appropriate and other variations are also possible.  FIG.  4    depicts housing  20  and connectors  10  may use a variety of different variations of the housing shown in  FIG.  4    or other housings such as the housing  20  shown in  FIG.  54    which has the locking feature on a separate component. Likewise, housing  20  may comprise one or more features for alignment during mating and may also comprise other features for securing or locking the connector in a suitable complimentary port or device. Housing  20  has a relatively compact form-factor such as having a length L of about 40 millimeters (mm) or less and a cross-section dimension of about 15 mm or less such as 12 mm or less, but other suitable dimensions are possible for the housing. 
       FIGS.  4 A- 4 D  are respective cross-sectional views of the housing of  FIG.  4    taken along respective planes defined by line  4 A- 4 A, line  4 B- 4 B, line  4 C- 4 C and line  4 D- 4 D. Lines  4 B- 4 B and  4 C- 4 C are taken at the same cross-section.  FIG.  4 E  is a side view of housing  20  that is similar to housing  20  shown in  FIG.  4   , but further includes threads  28  like housing  20  depicted in  FIGS.  3  and  4   . Threads  28  are disposed on the front portion FR of housing  20  and are discontinuous. 
     Housing  20  comprises the rear end  21  and the front end  23  with a longitudinal passageway  22  extending from the rear end  21  to the front end as shown in  FIG.  4 E . Housing  20  of  FIGS.  4 A- 4 E  comprises a part of the rear portion RP having a round cross-section RCS and a part of the front portion having a non-round cross-section NRCS. Transition region TR is disposed between the rear portion RP and the front portion FP of housing  20 . Transition region TR comprises a first transition portion TP 1  disposed on a first side of the housing and a second transition portion TP 2  disposed on a second side of the housing. In this version, the first transition portion TP 1  and the second transition portion TP 2  are spaced apart by an offset distance OD in the longitudinal direction of the housing  20  as best shown in  FIG.  4 E . The offset distance OD for the transition portion TP is useful since it allows connector only to fully-seat into complimentary devices or ports having the matching geometry. However, other housings  20  for connectors disclosed herein may omit the offset distance if desired. 
     Housings  20  may also have suitable features or structures for sealing connectors  10 . The sealing plane should be located at a suitable location along the housing  20  for providing suitable environmental protection as necessary for the desired environment. Illustratively, housing  20  may include one or more grooves  20 G for receiving an appropriately sized O-ring  65 . Housings  20  may include other feature or structures for aiding in sealing. For instance, the housing  20  may have a suitable surface for receiving a portion of a heat shrink  99  or the like for sealing between a portion of the cable  90  and the connector  10 . Any suitable heat shrink  99  may be used such as a glue-lined heat shrink. Moreover, other structures or features are possible for aiding in providing a robustly sealed cable assembly  100 . 
     As used herein, the transition region TR is disposed between the rear end  21  and the front end  23  where the housing  20  makes a transformational shift in the primitive cross-sectional shapes from a part of a rear portion RP to a part of the front portion FP. As used herein, a primitive cross-section means the outer perimeter of the cross-section without regard for the internal features of the cross-section. Further, portions of the cross-sections may include other features that modify the shape of the primitive cross-sections as desired such as a keying feature, retention feature or a locking feature, while still practicing the concepts of the transition region TR or front/rear portions as disclosed herein. For instance, a front portion FP may have rounded corners or chamfered corners while still being a rectangular cross-section. 
     In this embodiment of housing  20 , the front portion FP of housing  20  has a rectangular cross-section that provides a first orientation feature for the connectors for alignment during mating and inhibit insertion into a non-compliant device or port. The non-round cross-section NRCS has the rectangular cross-section with a width W 1  and a height H 1  as shown in  FIG.  4 B . The rectangular cross-section provides the first orientation feature since the rectangular portion may only be inserted into a complimentary device or port in certain orientations due to its rectangular shape, thereby inhibiting incorrect insertion or insertion into non-compliant devices or ports. 
     As best shown in  FIG.  4 C , housing  20  of  FIGS.  4 A- 4 E  has the first transition portion TP 1  that comprises a first riser dimension FRD from the non-round cross-section NRCS to the round cross-section RCS, and the second transition portion TP 2  comprises a second riser dimension SRD from the non-round cross-section NRCS to the round cross-section RCS, where the first riser dimension FRD is different that the second riser dimension SRD. The riser dimensions are measured perpendicular from the mid-point of the cord defined by the surface of non-round cross-section NCRS as shown in  FIG.  4 C  to the outer surface of the round cross-section RCS. 
     The geometry of housing  20  of  FIGS.  4 A- 4 E  also comprises the non-round cross-section NRCS comprising a rectangular cross-section having rounded corners RC, and the rounded corners RC are sized so they have a similar outer dimension OD as a dimension D for the round cross-section RCS. The rounded corners (RC) may provide stability and snug fit for the mated connector  10  within a port or device when side-pull forces are experienced to inhibit undue optical attenuation by having the round corners transition between the front portion FP to the rear portion RP. 
     The front portion FP of housing  20  depicted has more than one primitive cross-sectional shape over its length. Specifically, the front portion FP of housing  20  of  FIGS.  4 - 4 E  also comprises another cross-section portion ACSP. By way of explanation, the another cross-sectional portion (ACSP) may comprise a SC footprint. The SC footprint can, in part, be similar to the inner housing of a conventional SC connector. This particular housing footprint is useful for allowing the connectors disclosed to be backwards compatible into existing devices or ports using well-established connector footprints as desired. Other embodiments may have connectors configured for LC connector or other known connector footprints as desired. 
     As best shown in  FIGS.  4  and  4 D , the front portion FP of housing  20  may comprise another cross-section portion ACSP with a primitive cross-section that is different than the non-round cross-section NRCS depicted in  FIG.  4 D . More specifically, the non-round cross-section NRCS changes to another cross-section portion ACSP as shown. As depicted in  FIG.  4 D , the another cross-section portion comprises a rectangular cross-section with a width W 2  that is less than W 1  and a height H 2  is similar to height H 1 . By way of example, height H 2  may be equal to height H 1 . In one embodiment, the another cross-section portion ACSP has a primitive cross-section that is similar to a cross-section near a front end of a SC connector. 
     Likewise, the rear portion RP may have more than one primitive cross-section shape over its length as desired. Moreover, rear portion RP may include one or more retention features or locking features that alter or modify the cross-section. For instance, housing  20  may also include locking feature  20 L so that the connector may secured in an adapter, port or other suitable device. For instance, locking feature  20 L may comprise features integrated into the housing such as one or more of a groove, a shoulder such as shown in  FIG.  4 E  and  FIG.  45   , a scallop such as shown in the housing  20  of  FIG.  3   , a reverse bayonet such as depicted in  FIG.  44   , or a ramp with a ledge such as shown in  FIG.  71   . In these examples, the locking features  20 L advantageously are integrated into the housing  20  and do not require extra components and may be used with any of the disclosed concepts. In some embodiments, the locking features  20 L are subtractive portions from the primitive geometry of the rear portion RP such as a notch in the round rear portion RP. Consequently, having the locking features integrated into the housing  20  (e.g., monolithically formed as part of the housing) may allow denser arrays of connectors in complimentary devices. Moreover, these locking features integrated into the housing  20  are rearward of the sealing location of connectors  10 . For example, the integrated locking features of housing  20  are disposed rearward of at least one groove  20 G that seats O-ring  65 . Locking feature  20 L may cooperate with features of a complimentary mating device for securing the mating of the connector  10  with the complimentary mating device. 
     Housing  20  may also have features that aid in the proper alignment or orientation of the connector with the complimentary device such as markings, keys, keyways, etc. without changing the primitive form-factors of the housings that are disclosed and claimed herein. Additionally, housing may have other features for mating with a complimentary device or threads for securing a dust cap.  FIG.  2    is a perspective view of connector  10  with a housing  20  similar to the housing  20  depicted in  FIG.  4   , but it further includes threads  28  and keying feature  20 K.  FIGS.  25  and  26    depict a fiber optic connector similar to  FIG.  20    having an alternative housing  20 A that may be used with any suitable fiber optic connector disclosed herein. Housing  20  further comprises a keying feature  20 K. Keying feature  20 K has a predetermined location with respect to an orientation of housing  20  for aligning the form-factor of the housing with a respective mating device. For instance, the housing  20  or keying feature  20 L provides a proper orientation for connection in one orientation, which may be desired for connectors having angled ferrules. In this embodiment, keying feature  20 K ensures correct rotational orientation of the connector  10  during insertion and mating with another device. 
     In this particular embodiment, housing  20  is monolithically formed; however, other embodiments could have designs where the housing was formed from one or more components as desired. Housing  20  having a plurality of components could be assembled by snap-fitting, adhesive, welding or the like. Illustratively,  FIGS.  39  and  40    depict a housing  20  having a plurality of components. 
     Returning to the description of connector  10  of  FIG.  3    and its components,  FIG.  5    is an exploded view of ferrule subassembly  60  shown in connector  10  of  FIG.  3   . Ferrule subassembly  60  may have several different constructions as depicted herein and still practice the concepts disclosed. For instance, ferrule subassemblies  60  may use different ferrule carrier  40  constructions such as disclosed or desired while still practicing the concepts disclosed. 
     Ferrule  30  is a portion of ferrule subassembly  60 . In these embodiments, an opening  21 A at the rear end  21  of the housing  20  is sized for receiving a portion of the ferrule subassembly  60 . When assembled, the ferrule subassembly  60  is configured to cooperate with the housing  20  for inhibiting the rotation of the ferrule subassembly  60  with respect to the housing  20 . For instance, the ferrule subassembly may have a friction fit or interlocking structure that cooperates with the passageway  22  of the housing  20  that inhibits rotation of the ferrule subassembly  60  with respect to housing  20 . However, in other embodiments the ferrule subassembly  60  may be free to rotate for tuning or the like until the ferrule subassembly  60  is fixed in position relative to housing  20  such as with an adhesive or the like. 
     As depicted in  FIG.  5   , ferrule subassembly  60  comprises a ferrule carrier and a resilient member  50 . Some embodiments of the ferrule subassembly  60  may omit the resilient member  50  and not bias the ferrule  30  forward. If a resilient member  50  is used, ferrule carrier  40  may further comprise a resilient member pocket  46  as shown. As depicted, the resilient member pocket  46  may be configured for receiving the resilient member  50  in a direction transverse to a longitudinal direction of the ferrule carrier  40  (e.g., transverse to the optical fiber passageway) as represented by the arrow. 
     As shown in  FIG.  5   , ferrule carrier  40  comprises a ferrule carrier rear end  41 , a ferrule carrier front end  43  and a ferrule carrier passageway  42  extending from the ferrule carrier rear end  41  to the ferrule carrier front end  43 , where the ferrule carrier passageway  42  comprises a fiber buckling zone  47 . The fiber buckling zone allows the optical fiber  92  to have room to move rearward during mating without causing undue optical attenuation. In other words, during mating the ferrule  30  may be pushed rearward slightly cause the optical fiber  92  of the cable  90  to deflect and in order to inhibit optical attenuation the fiber buckling zone  47  provided for allowing fiber movement. 
     Ferrule carrier  40  may have several different designs. In one embodiment, the ferrule carrier comprises a ferrule carrier front end  43  with the ferrule carrier front end  43  comprising at least one cantilevered portion such as shown in  FIG.  10   . Generally speaking, the at least one cantilevered portion extends from a medial portion of the ferrule carrier and allows the assembly of the ferrule  30  into the ferrule carrier  40 . The at least one of the first cantilevered portion  43 A may also be configured to cooperate with the housing  20  for inhibiting the rotation of the ferrule  39  with respect to the housing  20  when the ferrule subassembly  60  is fully-seated in the housing  20 , and allow rotation of the ferrule  30  for tuning when the ferrule subassembly  60  is not seated in the housing  20 . 
     By way of explanation and example, the front portion of the longitudinal passageway  22  of housing  20  may be sized for snuggly fitting to shoulders  43 S disposed on the ferrule carrier front end  43  so that one or more of the cantilevered portions either squeeze the ferrule  30  and inhibit rotation or inhibit the deflection of the at least one cantileved portion so that the ferrule  30  is inhibited from rotating beyond its desired location. However, the ferrule carrier  40  still allows the ferrule  30  to “float” to the desired degree so it can translate such as in the rearward direction (i.e., z-direction) or X-Y directions for allowing the ferrule to move slightly to the desired location for precise alignment during mating. For instance, the ferrule  30  is biased and may “float” on the resilient member. 
     The use of the ferrule carrier described herein should not be confused with a ferrule holder that fixes a conventional ferrule directly to the ferrule holder so there is no appreciable movement between the ferrule and the ferrule holder. Conventional connectors allow the entire assembly of the ferrule holder/ferrule to be biased by a spring. On the other hand, embodiments such as depicted in  FIG.  3   ,  FIG.  17    and  FIG.  21    allow the ferrule to float without using a ferrule holder. Moreover, the use of the ferrule holder/ferrule assembly is another component interface where stack-up of tolerances may exist and impact geometry. Consequently, connectors disclosed herein may eliminate the conventional ferrule holder along with the expense and manufacturing time required by using a conventional ferrule holder. 
       FIG.  5    depicts the ferrule carrier front end  43  comprising a first cantilevered portion  43 A and a second cantilevered portion  43 B.  FIGS.  6  and  7    are longitudinal sectional views of ferrule subassembly  60  of  FIG.  3    showing details of the design and assembly.  FIGS.  8  and  9    respectively are a perspective view and close-up perspective view of ferrule carrier  40  of  FIGS.  5 - 7    depicting details of the ferrule carrier. 
     In this embodiment, at least one of the first cantilevered portion  43 A or the second cantilevered portion  43 B are configured to cooperate with the housing  20  for inhibiting the rotation of the ferrule  30  with respect to the housing  20  when the ferrule subassembly  60  is fully-seated in the housing  20 , and allow rotation of the ferrule  30  for tuning when the ferrule subassembly is not seated in the housing  20 . By way of explanation, ferrule carrier front end  43  of  FIG.  5    may be sized to cooperate with the housing  20  by fitting into a passageway  22  that inhibits the cantilevered portions  43 A,  43 B from deflecting outwards, thereby inhibiting the rotation of the ferrule  30  with respect to the ferrule carrier  40  when the ferrule carrier front end  43  is fully-seated in the housing  20  since some of the selectively tunable surfaces  36  (in this case the planar surfaces  36 S) of ferrule  30  cooperate with ferrule retention structure  43 C of the ferrule carrier  40 . 
     Ferrule subassembly  60  is assembled by placing the resilient member  50  into the resilient member pocket  46  by inserting the spring in the transverse direction to the ferrule carrier passageway as best shown in  FIG.  5   . Ferrule carrier  40  of  FIG.  5    allows ferrule  30  to be inserted from the ferrule carrier front end  43  as represented by the arrow. As ferrule  30  is inserted into the ferrule carrier front end  43  the first cantilevered portion  43 A and the second cantilevered portion  43 B deflect outward as represented by the arrows shown in  FIG.  6   . As the ferrule  30  is seated in the ferrule carrier front end  43  the first cantilevered portion  43 A and the second cantilevered portion  43 B spring back toward their original positions to capture the ferrule  30 . As best shown in  FIGS.  7  and  9   , one of the first cantilevered portions  43 A or the second cantilevered portions  43 B comprise a ferrule retention structure  43 C. Consequently, when the first and second cantilevered portions  43 A,  43 B are inhibited from deflecting, then ferrule  30  is inhibited from rotating such as when the ferrule subassembly  60  is fully-seated within housing  20 . However, when the first and second cantilevered portions  43 A,  43 B are allow to deflect outwards such as shown in  FIG.  6   , then the ferrule  30  may be rotated thru any desired angle θ for tuning. 
     Further, the rear end of ferrule carrier  40  may have other features that allow tuning if desired. For instance, ferrule carrier rear end  41  may have a ferrule carrier groove  41 G or shoulder for cooperating with the cable adapter  59 , thereby allowing rotation between the two components in either step increments or infinite increments as desired and discussed herein. By way of example, ferrule carrier  40  may comprise one or more ferrule carrier rotational keys  41 K to allow rotational step increments or the ferrule carrier  40  may omit ferrule carrier rotational keys  41 K and allow infinite rotational positions relative to the cable adapter  59 , which may be keyed to the rear end  21  of housing  20 . Ferrule carrier  40  may be attached to cable adapter in any suitable manner such as adhesive, welding, mechanical fitment, etc. 
     Other embodiments may integrate the ferrule carrier  40  and cable adapter  59  into a monolithic component. However, using separate cable adapter  59  allows the connectors  10  to be adapted to different cables such as round, flat, different sizes by merely selecting the appropriate sized cable adapter  59  for the desired cable type. Additionally, cable adapter may include one or more flexures  59 F at the rear portion for providing cable bending strain-relief if desired instead of using a conventional boot. The flexures as depicted are suitable for flat cables that have a preferential bend-characteristic. 
     Again, the connectors disclosed herein may allow the ferrule  30  to have a small amount of “float” within ferrule carrier or housing without using a ferrule holder like conventional fiber optic connectors. Conventional connectors mount the ferrule within a ferrule holder in a fixed position and then typically the ferrule holder is biased by a spring. On the other hand, some of the connector designs disclosed by the present application have the resilient member  50  directly bias the ferrule, which eliminates parts and also allows more flexibility for ferrule selection or tuning. Moreover, the ferrule may be tuned relative to the ferrule carrier or the housing depending on the connector design. Further, the high precision geometry ferrule holder is eliminated along with the tolerance stack-up using a conventional connector with a ferrule holder. However, the housings concepts disclosed herein may be used with connectors having ferrule holders such as disclosed in  FIGS.  70 - 78   . 
     Ferrule retention structure  43 C is configured to cooperate with geometry on ferrule  30 . Specifically, ferrule  30  depicted in  FIG.  5    has at least one selectively tunable surface  36  that cooperates with the ferrule retention structure  43 C. Ferrule retention structure  43 C is sized for snugly-fitting to one or more selectively tunable surfaces  36  of ferrule  30  as shown in  FIG.  7   . However, when the ferrule carrier  40  is not seated in housing  20 , the ferrule  30  may be rotated within ferrule carrier  40  about an angle θ for optically tuning the assembly. Ferrule  30  may have a round selectively tunable surface  36  for infinite tuning, but that requires a tight fit between the ferrule carrier front end  43  and the appropriate portion of the passageway  22  of the housing  20 . If the ferrule  30  uses selectively tunable surfaces  36  comprising a plurality of planar surfaces  36 S, then the appropriate portion of the passageway  22  merely has to inhibit deflection of the at least one cantilever arm so that the ferrule  30  is inhibited from rotation when fully assembled.  FIGS.  8  and  9    depict detailed views of the ferrule carrier  40  of  FIG.  5   . As depicted, the first and second cantilevered portions  43 A,  43 B of ferrule carrier  40  may have stepped down portions forward of shoulder  43 S, thereby allowing robust seating and inhibiting of deflection of the cantilevered arms  43 A,  43 B. 
     Ferrule  30  may have any suitable number of plurality of planar surfaces  36 S as desired. By way of explanation, four planar surface  36 S allows quadrant tuning and further planar surfaces allows finer tuning in a first-stage. However, ferrules  30  may have any number of planar surfaces as desired such as six or eight planar surfaces to increase the number of steps for tuning the ferrule. Generally speaking, quadrant tuning is sufficient and if coupled with an infinite second-stage tuning interface, then the connector advantageously may be tuned to any desirable rotational position in a quick and easy manner during manufacturing. 
       FIG.  10    is a perspective view of an alternative ferrule carrier  40 ′ that may be used in the ferrule subassembly  60  and  FIGS.  11  and  12    respectively are a partially exploded view and an assembled view of the alternative ferrule carrier  40 ′ in ferrule subassembly  60 . This ferrule carrier  40 ′ is similar to ferrule carrier  40 , but only has first cantilevered arm, and requires loading of the ferrule  30  from the transverse direction like the resilient member  50 . Ferrule  30  may still be rotated with respect to ferrule carrier  40 ′, but it may require a slightly larger rotational force to deflect the U-shaped portion or a slightly upward translation of the ferrule  30  to help reduce the rotational force required for the rotation. 
       FIGS.  13  and  14    respectively are a partial sectional view and a cross-sectional view of the alternative ferrule carrier  40 ′ of  FIGS.  10 - 12    depicted assembled into ferrule subassembly  60  and disposed in housing  20  of fiber optic connector. As depicted, the passageway  22  of housing  20  may include different geometry for seating the ferrule subassembly  60  within the housing and inhibiting the rotation of ferrule  30  relative to the housing  20  using the alternative ferrule carrier  40 ′. As depicted, housing  20  comprises a passageway  22  with an internal key  20 KI that cooperates with the U-shaped portion of the alternative ferrule carrier  40 ′. Consequently, the alternative ferrule carrier is inhibited from further rotation with respect to the housing  20 . 
       FIG.  17    is an exploded view of another cable assembly  100  that is similar to the cable assembly  100  of  FIG.  2    with a fiber optic connector having a different ferrule subassembly  60  and  FIG.  18    is a partially exploded view of the cable assembly  100  of  FIG.  17    with the fiber optic cable attached to the ferrule subassembly  60 . This cable assembly  100  comprises a connector  10  that has a ferrule carrier  40  that is monolithically formed with the cable adapter as depicted. Otherwise, the cable assembly  100  is similar to the cable assembly  100  of  FIG.  2   . 
     The concepts disclosed herein may be used with other types and designs of connectors. For instance,  FIGS.  19 - 43    and  FIGS.  46 - 53    disclose connectors where ferrule  30  is inserted from a front end  23  of the connector  10 . These connectors designs are depicted without a ferrule holder as generally discussed herein, but may be used with a ferrule holder if desired. These connector designs are different from the earlier connector designs since they do not use a ferrule carrier; however, these designs can still be optically tuned if desired. Specifically, these connector designs comprise a ferrule  30  that “floats” relative to the housing  20  and uses a different structure for securing the ferrule while allowing the ferrule float. Any suitable housings  20  as described herein may be used for these connectors so long as they are suitably modified for securing the ferrule  30  as disclosed in more detail below. 
     Illustratively,  FIGS.  19  and  20    are perspective views of cable assembly  100  having a different fiber optic connector  10  with housing  20  that is similar to the housing shown with the fiber optic connector of  FIG.  2   , but having ferrule  30  that loads from the front end  23  of housing  20  and secured a transverse ferrule retention member  140 .  FIG.  21    is an exploded view of another cable assembly  100 , that is similar to that of  FIG.  19    with the connector having a housing having threads on the housing that are discontinuous.  FIG.  22    is an perspective assembled view of the cable assembly  100  of  FIG.  21    and  FIG.  23    is a perspective view of the cable assembly  100  of  FIG.  22    with a dust cap  70  installed.  FIG.  24    is a longitudinal sectional view of the cable assembly  100  of  FIG.  22    in a vertical direction and  FIG.  29    is a longitudinal sectional view of a front portion of the fiber optic connector  100  in a horizontal direction. 
     With reference to  FIG.  21   , connector  10  comprises housing  20 , ferrule  30  and transverse ferrule retention member  140 . Housing  20  is similar to the other housings disclosed herein, but further comprises an opening  129  in an outer surface that is transverse to the longitudinal passageway  22  of housing  20 . The opening  129  is sized for receiving the transverse ferrule retention member  140  and securing the ferrule  30  in a manner that allows suitable movement so it may float as appropriate as depicted in  FIG.  24   . Connector  10  may also comprise a band  69  for securing a cable  90  to the connector if desired. 
       FIG.  25    is a detailed exploded view of the front end of the cable assembly  100  of  FIG.  22    and  FIG.  26    is a cross-sectional view taken at the opening  129  of the housing  20  of  FIG.  19    showing transverse ferrule retention member  140  securing the ferrule  30 . As depicted in  FIG.  25   , ferrule  30  is loaded into the passageway  22  of housing  20  from the front end  23  and secured by the cooperation of the ferrule  30  with the transverse ferrule retention member  140  that is inserted into opening  129  for cooperating with at least one surface of the ferrule  30 . Specifically, ferrule  30  is inserted into the passageway  22  until the cooperating surface such as a ferrule retention feature aligns with the opening  129  so that the transverse ferrule retention member  140  may engage the surface and securing the ferrule. Additionally, the at least one surface of the ferrule  30  that serves as the ferrule retention feature cooperates with the transverse ferrule retention member  140  is sized relative to the transverse ferrule retention member so that the ferrule  30  may float. The ferrule retention feature may also be the same feature as the at least one selectively tunable surface  36 . 
     In this embodiment, ferrule has at least one selectively tunable surface  36  so that ferrule  30  may have at least two rotational orientations with respect to the housing  20  (and which acts as the ferrule retention feature). However, ferrules  30  may have any suitable numbers of selectively tunable surfaces  36  so the ferrule  30  may have the desired number of rotational positions for tuning the ferrule. By way of example, ferrule may have four, six, eight or any suitable number of selectively tunable surfaces  36  as desired. More specifically, the longitudinal passageway  22  of housing  20  extending from the rear end  21  to the front end  23  also comprises a tuning pocket  24  in cooperation with the longitudinal passageway  22 . The tuning pocket  24  allow the rotation or manipulation of the ferrule  30  within the housing as needed. In this embodiment, the transverse ferrule retention member  140  is secured to the housing  20  using a pair of catches  140 C disposed on the arms of the transverse ferrule retention member  140 . Catches  140 C may snap-fit to portions of the housing  20  disposed in opening  129  such ledges. However, other variations for securing the ferrule  30  are possible. By way of example,  FIGS.  27  and  28    respectively depict a detailed view of an alternative transverse ferrule retention member  140  having catches  140 C and cross-sectional view showing the alternative transverse ferrule retention member  140  for securing ferrule  130 . As best depicted in  FIG.  27   , the catches  140 C are disposed on a medial portion of the arms of this alternative transverse ferrule retention member  140 . Consequently, the catches  140 C cooperate with a portion of ferrule  30  as depicted in  FIG.  28   , instead of the housing  20  as depicted in  FIG.  26   .  FIG.  29    is a sectional view of a portion of the housing  20  having a width of opening  129  being larger than the width of the transverse ferrule retention member  140  so that the ferrule  30  may float.  FIG.  30    is a sectional view depicting tuning pocket  24  of housing  20  that allows rotational tuning of the ferrule  30  during manufacture for improving optical performance. Specifically, when transverse ferrule retention member  140  is disengaged, then the ferrule  30  may be rotated relative to the ferrule. As depicted, tuning pocket  24  allows ferrule  30  to be rotated by a suitable angle θ for optical tuning to a preferred rotational position as represented by the arrow. By way of example, ferrule  30  may be rotated by an angle θ of ±180 degrees, but other suitable angles are possible. 
       FIGS.  31  and  32    depict explanatory ferrules  30  having at least one selectively tunable surface  36 .  FIG.  31    shows a ferrule that may be tuned to quadrants with four selectively tunable surfaces  36 . Generally speaking, the selectively tunable surfaces  36  are configured as planar surfaces as shown. More specifically, the selectively tunable surfaces  36  are formed by a plurality of planar surfaces that are recessed on the ferrule  30 . Finer tuning is possible with the concepts disclosed by having more selectively tunable surfaces such as six, eight, ten or twelve, thereby providing more rotational positions for securing the ferrule  30 .  FIG.  32    depicts a ferrule  30  where the selectively tunable surfaces  36  are disposed adjacent to a free rotation portion  36 A of the ferrule  30 , thereby allowing rotation of the ferrule for tuning during assembly without removing the transverse ferrule retention member  140 . By way of explanation, the ferrule  30  in  FIG.  32    may be secured by transverse retention member  140  and when rotational tuning is required, then the ferrule  30  may be displaced rearward until free rotation portion  36 A is aligned with the transverse retention member  140  allowing rotation of the ferrule in either direction and when the desired rotational position is reached the ferrule  30  is allowed to translate to the forward position where the selectively tunable portions  36  engage and cooperate with the transverse ferrule retention member  140  to inhibit rotation of the ferrule  30 . Consequently, the transverse ferrule retention member  140  does not need to be removed from housing  20  for tuning. 
       FIGS.  33 - 36    are various views of depicting the housing  20  of the connector  10  of  FIG.  23    comprising opening  129  and tuning pocket  24 . As depicted, housing  20  is similar to the other housings and may be modified for the desired housing configuration as desired. For instance, although the housing  20  depicts threads  28  that are discontinuous for attaching dust cap  70  such as shown in  FIG.  23   , variations are possible that eliminate the threads  28  and use a push-on dust cap. Likewise, other variations to the housing  20  are possible such as changing the mating geometry and using the concepts disclosed with the mating geometry of the housing  20  depicted in  FIG.  54   . Further, housings  20  may have different retention features or different locking features  20 L. By way of comparison, housing  20  of  FIG.  3    comprises a locking feature  20 L disposed between rear end  21  and a front end  23  configured as a scallop and the locking feature  20 L of the housing of  FIG.  4    is configured by a shoulder. The shoulder comprises an enlarged annular portion  126  with a flat surface on the rear side. 
     By way of example,  FIG.  37    is a perspective view of another cable assembly  100  with still another alternative connector  10  that is similar to connector  10  of  FIG.  19   , but further comprises multi-piece housing  20  comprising a nosepiece  160 .  FIG.  38    is a perspective view of the cable assembly  100  with dust cap  70  and  FIG.  39    is an exploded view of the cable assembly  100 . 
     As best depicted in  FIG.  39   , the connector  10  comprises a housing  20  having nosepiece that fits about a front end  23 . In this configuration, using the separate nosepiece  160  provides more access to the passageway  22  of the housing and allows more room and vision for assembly. Moreover, the opening  129  is disposed in a location that is covered by nosepiece  160  so that once the connector is tuned and the nosepiece  160  is secured the transverse ferrule retention member is not visible or accessible. Housing  20  of this embodiment also has a different locking feature  20 L compared with the housing depicted in  FIG.  33 - 36    and an aperture  29 . Locking feature  20 L is configured as a groove for receiving a clip or other suitable locking feature from a complimentary device for retaining the connector in a mated state when secured. This embodiment of the connector also use cable adapter  59  so that the connector may accommodate different cable types by using the appropriately sized cable adapter for the given cable  90 . 
       FIG.  40    is a front end sectional view of the connector  10  of  FIG.  37    showing the nosepiece  160  attached to the front end of housing  20  and  FIG.  41    is a front end view of the housing showing an attachment interface (not numbered) such as a weld interface disposed on a front portion of the housing  20 . As depicted in  FIG.  40   , once the nosepiece  160  is installed it inhibits the removal of the transverse ferrule retention member  140 . In other words, the transverse ferrule retention member  140  is not visible, nor is it accessible once the nosepiece is installed. Consequently, once the connector is tuned and the nosepiece is suitable installed, the transverse ferrule retention member  140  is tamper-resistant. The attachment interface of the housing provides a surface for attaching nosepiece  160 . Nosepiece  160  may be attached in any suitable manner such as adhesive, friction-fit, snap-fit, welding or the like as desired. In one embodiment, the nosepiece  160  is formed from a translucent material. Using a translucent material for nosepiece  160  allows the use of a UV curable epoxy for securing the nosepiece  160 . 
     Still other variations of connectors are possible using modified housings or other modified components.  FIGS.  42  and  43    are perspective and side views of a connector  10  similar to  FIG.  37    having an alternative housing  20 . Housing  20  in this embodiment does not have an offset distance among transition portions TP 1 -TP 4 . In other words, all of the transition portions TP 1 -TP 4  are aligned. Additionally, this housing  20  comprises keying feature  20 K for orienting the connector for mating. Keying feature  20 K is a key, but other embodiments may use other suitable structure such as a keyway or the like. 
     Other variations of housings disclosed herein are also possible such as having other shapes for the rear portion RP such as a polygon cross-section PCS, instead of the round cross-section RCS. Polygon cross-sections may have any suitable number of side such as four, five, six, seven or eight, but other suitable number of sides are also possible. Still other variations are possible with the housing concepts disclosed. For instance, the housing  20  of the connectors may be configured to work with other devices so that a retention feature or locking feature of the connector is intended to cooperate with different devices for maintaining the optical connection at the mating interface. By way of example,  FIGS.  44  and  45    are perspective views of portions of alternative housings  20  depicting other locking feature designs. The housings  20  depicted in  FIGS.  44  and  45    may be used with any suitable connectors disclosed herein. Likewise, locking or retention features may be selected with other features such as keying features  20 K. Keying feature  20 K has a predetermined location with respect to an orientation of housing  20  for aligning the connector form-factor with a respective mating device. Specifically, the housing  20  provides a proper orientation for connection in one orientation, which may be desired for angled ferrules. In this embodiment, keying feature  20 K is disposed on a center line of fiber optic connector  10  and ensures correct rotational orientation during insertion and mating with another device. 
     Components or features of connectors may be selected as desired to form other variations of connectors. Illustratively,  FIG.  46    is a perspective view of still another cable assembly  100  using a connector similar to the connector of  FIG.  37   , but having a different cable adapter  59 . The connector also has a different type of locking feature  20 L than the housing  20  of the connector of  FIG.  37   . Like the cable adapter  59  of  FIG.  37   , the cable adapter  59  of this embodiment that fits into a rear opening  21 A of the housing  20 . As discussed, using connectors with a separate cable adapter  59  allows the connector to be used with different types cables by merely changing out and selecting the cable adapter that is suitable for the desired cable  90 .  FIGS.  47  and  48    respectively are a perspective view and a cross-sectional view the cable adapter  59  of  FIG.  46   .  FIG.  49    is a vertical sectional view and  FIG.  50    is a horizontal sectional view of the rear portion of cable assembly  100  showing the cable  90  disposed within the cable adapter  59 . 
       FIGS.  47 A and  48 A  are a perspective view and a cross-sectional view of another cable adapter  59 , that is similar to the cable adapter of  FIG.  47   . As depicted, cable adapters  59  may comprise an aperture  59 A, a recessed surface  59 R, a shoulder  59 S, a passageway  59 P, and a cable saddle  59 C or a cable adapter key  59 K as desired for any particular embodiment of cable adapter  59 . Generally speaking, cable adapter  59  comprises passageway  59 P from a cable adapter front end  59 F to a cable adapter rear end  59 R. Passageway  59 P allows the optical fiber  92  of cable  90  to pass therethrough. Shoulder  59 S allows cable adapter  59  to have a snug-fit within the passageway  22  of housing  20  and inhibits adhesive from wicking or flowing forward of the shoulder  59 S. Any adhesive or epoxy used for securing cable adapter  59  may wick around the recessed surface  59 R for creating a sufficient bonding area and any excessive adhesive or epoxy may flow into the aperture  59 A. Housings  20  may include one or more aperture  29  for injecting epoxy or adhesive or the adhesive or epoxy may be placed on the cable adapter before insertion into the housing. For instance, housing may include two apertures  29  such as show in  FIG.  49    so that air may escape as adhesive or epoxy is injected. Additionally, the one or more apertures  29  may be aligned with the apertures  59 A of the cable adapter so that the adhesive or epoxy also secures the strength members  94  of cable  90  to the cable adapter  59  that is secured to the housing  20 , thereby forming a robust cable/connector attachment and also providing sealing at the rear end. Cable saddle  59 C is sized and shaped for the particular cable  90  that is intended to be secured using the cable adapter along with the appropriate components as appropriate such as depicted in  FIG.  50   . The rear portion of the cable adapter  59  may have a cable bend relief area such as a reverse funnel at entrance to the passageway, flexures or other suitable structure for inhibiting sharp bending of the cable near the rear of the cable adapter  59 . Further, cable adapters  59  may or may not include keys  59 K as desired for cooperating with features of the housing. The rear portion  59 R of the cable adapter  59  of  FIG.  47 A  comprises one or more ribs  59 RB suitable for receiving a boot or overmold on the rear portion  59 R. The ribs  59 RB aid in the retention of the boot or overmold. 
       FIG.  51    is perspective view of another cable assembly  100  according to the concepts disclosed and  FIG.  52    is an exploded view of the cable assembly  100 . Housing  20  of this embodiment is similar to the housing disclosed herein, but further comprises a keying portion  20 KP that extends into the transition region TR as shown, but embodiments without the keying portion  20 KP are possible. The transition region TR of this housing is asymmetric. Specifically, the asymmetric transition region is a threaded portion TP, but other asymmetric geometries are possible as disclosed herein. In this embodiment, the keying portion  20 KP is configured as a female key or a subtractive portion on housing  20  such as a female keyway or a slice on the side of the connector leaving a D-shape. The keying portion  20 KP extends into the transition region as shown. The keying portion  20 KP cooperates with a suitable keying portion in a connection port of a device such as an additive or male portion for inhibiting non-compliant connectors from being inserted into the connection port. Although, the keying portion  20 KP is disposed about 180 degrees from the at least one locking feature  20 L, other arrangements are possible where the keying portion  20 KP is disposed less than 180 degrees from the at least one locking feature  20 L. In other embodiments, keying portion  20 KP may be arranged as a subtractive portion that removes a side or slice of the housing  20  for creating a D-shaped cross-section over the length of the keying portion  20 KP; instead of the female keyway shown. 
     The internal construction of connector  10  of  FIG.  52    is similar to that of  FIGS.  70 - 78    where ferrule  30  disposed within a ferrule holder  49  and inserted from a front end  23  of the connector  10  and is discussed in more detail in relation to those FIGS. This embodiment also comprises a boot or overmold  259  disposed on the rear portion  59 R of cable adapter  59  as best shown in  FIG.  53   . Further, when assembled a sealing element such a heat shrink  99  is disposed over the boot or overmold  259  as best shown in  FIG.  54   . The sealing element may also be disposed over a portion of the housing  20  as shown. Placing the sealing element over boot or overmold and a portion of the housing  20  allows for sealing of the cable jacket to the rear of the connector. This may also improve the bending strain-relief for the cable assembly. 
       FIG.  51 A  is a rear perspective view of another cable assembly having cable adapter  59  with flexures  59 F for bend-strain relief.  FIGS.  52 A and  53 A  are a side and sectional views of the cable assembly of  FIG.  51 A  showing heat-shrink  99  before and after being installed. As depicted, if the cable adapter  59  uses flexures  59 F they are generally aligned with the flat portions of cable  90  for cable bend relief. Also the cable adapter  59  may or may be able to have more than one rotational position with respect to the housing  20  depending on how the ends of the components cooperate or not. As depicted in  FIG.  53 A , housing  20  may have a stepped down portion at the rear end  21  for receiving a portion of heat shrink  99  and may cover the flexures  59 F while also providing further cable bending strain-relief. 
     Still other variations of housings  20  are possible using the connector concepts disclosed herein. The other connector embodiments disclosed included locking features  20 L that were integrated into the housing  20 ; however, other connectors may use locking features that are separate and distinct components from the housing  20 . Although this may require a bigger connector footprint or more access space between connectors the concepts of separate and distinct components for the locking features are possible.  FIG.  54 A  is a front perspective view of another housing  20  that may be used with the fiber optic connector concepts disclosed herein. In this embodiment, the securing feature is formed on a separate and distinct component from the housing  20 . Specifically, securing feature is disposed on a coupling nut  120  having threads and that rotates about an outer shaft of housing  20  for securing the connector to a complimentary device. Additionally, the housing  20  may not have offset distance between transition portions of the housing  20  such as depicted in this embodiment. 
     Connectors disclosed herein may be portions of other cable assemblies as desired. For instance,  FIG.  55    depicts a distribution cable  100 ′ having one or more connectors  10  on tether cables  90 ′ that extend from a mid-span access  93  of a distribution cable. Of course, other suitable assemblies may use the connectors according to the concepts disclosed herein. 
     By way of example, connectors disclosed herein may be converted from a first connector footprint to a second connector footprint.  FIG.  56    is a perspective view of an explanatory connector  10 ′ that further comprises a conversion housing  80  attached about the housing  20  for changing the connector  10 ′ from a first connector footprint to a second connector footprint and  FIG.  57    is a sectional view of the connector  10 ′. By way of example, the connector  10 ′ may have a first connector footprint such as shown in  FIG.  19    and be changed to a second connector footprint such as a SC connector by adding conversion housing  80 . However, any of the suitable connectors disclosed herein may be converted as described herein. Conversion housing  80  cooperates with housing  20  for changing from the first connector footprint to the second connector footprint. In this embodiment, the changing of the first connector footprint to the second connector footprint comprises the use of a single component. 
     In other embodiments, the changing of the first connector footprint to the second connector footprint may comprise the use of a plurality of components. Illustratively,  FIG.  58    is a partially exploded view of another connector  100 ′ that may be changed from a cable assembly  100  having first connector footprint  10  to a second connector footprint  10 ′ as shown assembled in  FIG.  59   . Further, this embodiment of the second connector footprint  10 ′ comprises a hardened connector footprint. Hardened connector footprint means that the connector is suitable for outdoor environments without be protected within a closure. Any suitable connector  10  disclosed herein may be used for such a conversion from the first footprint to the second footprint.  FIG.  58    depicts cable assembly  100  with connector  10  with the plurality of components for the conversion to the second footprint exploded for depicting the assembly of the components. In this particular embodiment, the plurality of components are suitable for converting connector  10  to a hardened OptiTap® compatible connector; however, the plurality of components may be configured for converting connector  10  into other hardened connectors as desired. In this embodiment, the plurality of components for the conversion to the hardened connector comprise an inner boot  83 , an outer boot  87 , a conversion housing  82  configured as a shroud, a retaining member  84  configured as a retaining nut and a coupling nut  85 . To make the conversion to the hardened connector, the inner boot  83  is slid over up over part of connector  10  and the conversion housing or shroud  82  is slid rearward into position and then the retaining nut  84  is secured to the threads of connector  10 . The coupling nut  85  is slid onto shroud  82  and then outer boot  87  can be slid-up into position from the rear. Shroud  82  may include an O-ring  86  for sealing during mating.  FIG.  60    is an assembled view of the fiber optic connector of  FIG.  58    showing the hardened second connector footprint with the dust cap  88  installed thereon.  FIG.  61    is a sectional view of the hardened connector of  FIG.  60   . 
     Still other embodiments for the conversion of connectors  10  are possible according to the concepts disclosed herein. By way of example, connectors  10  similar to the connector  10  of  FIG.  2 A  with the transition region TR having a threaded portion TP may be converted to other connectors.  FIG.  62    depicts cable assembly  100  having connector  10  with a connector housing  20  comprising a transition region TR having a threaded portion TP similar to connector  10  of  FIG.  2 A .  FIG.  63    shows the connector  10  of  FIG.  62    with a conversion housing  82  attached about the housing  20  for changing connector  10  with a first connector footprint to a connector  10 ″ with second connector footprint. Second connector footprint for connector  10 ″ comprises a hardened connector footprint, thereby converting cable assembly  100  to cable assembly  100 ″. 
       FIG.  64    is a partially exploded view of connector  10 ″ of  FIG.  63   . This particular conversion uses a plurality of components for converting connector  10  to a hardened OptiTap® compatible connector  10 ″; however, the plurality of components may be configured for converting connector  10  into other hardened connectors as desired. The plurality of components for the conversion to connector  10 ″ comprise the conversion housing  82  configured as shroud, a retaining member  84  configured as a retaining clip, and a coupling nut  85 . Shroud  82  may include one or more O-rings  86  for sealing during mating with a complimentary device. 
     To make the conversion to the connector  10 ″, the shroud  82  is slid into a passageway of coupling nut  85  as shown and then slid over connector  10  from the front end. Next, the shroud  82  is rotated so that the internal threads  82 T of shroud  82  as best shown in  FIG.  65    engage with the threaded portion TP of connector  10  until the shroud  82  is secured to connector  10 . Thereafter, retaining member  84  is aligned with the front end of the shroud  82  and then pushed onto the connector  10  until it is seated and retained on housing  20 , thereby inhibiting the shroud  82  from backing off the threaded portion TP of connector  10  as depicted in  FIG.  66   . 
       FIG.  67    is a detailed sectional view of the front end of connector  10 ″ showing the retaining member  84  secured to connector  10  and  FIGS.  68  and  69    are perspective views of the retaining member  84 . As depicted, retaining member  84  comprises an opening  840  at the front for receiving a portion of housing  20  therethrough when installed. Additionally, retaining member  84  also has a front flange  84 F shaped to the passageway of shroud  82  so it may be inserted and engage connector  10 . Retaining member  84  may also include one or more keyways  84 K for allowing the retaining member to slide past keying feature  20 K of connector  10 . Windows  84 W disposed on opposite sides of retaining member  84  engage with ears  27  of housing  20  for securing the retaining member  84  to connector  10 . Once installed, retainer member  84  inhibits the shroud  82  from rotating and coming off connector  10 . Connector  100 ″ may also include a dust cap  88  like connector  10 ′ of  FIG.  60   . 
     The connector concepts disclosed herein may be used with still other connector designs such as connectors using a ferrule disposed in a ferrule holder.  FIGS.  70 - 78    disclose a cable assembly  100  comprising connector  10 . Connector  10  of  FIGS.  70 - 78    is similar to other connectors  10  disclosed herein, but it has ferrule  30  disposed within a ferrule holder  49  and inserted from a front end  23  of the connector  10  as depicted in  FIG.  75   . Housing  20  of the connector  10  of  FIGS.  70 - 78    is similar to other housings  20  discussed herein and differences with be described while other details will not be repeated for the sake of brevity. 
       FIGS.  70  and  71    respectively are perspective and sectional views showing cable assembly  100  comprising connector  10  having a ferrule  30  disposed within a ferrule holder  49 , thereby forming a ferrule sub-assembly (not numbered) that is biased to a forward position by resilient member  50 . When assembled, ferrule sub-assembly ( 60 ) is configured to cooperate with the housing ( 20 ) for inhibiting the rotation of the ferrule subassembly ( 60 ) with respect to the housing ( 20 ) as best shown in  FIG.  78   . 
     As depicted in  FIG.  70   , connector  10  is configured so that conversion housing  80  may be attached to housing  20  for converting to an SC connector. Likewise, connector  10  has housing  20  with a transition region TR with a threaded portion TP similar to the housing  20  depicted in  FIG.  2 A  so it may be converted to a hardened connector as depicted in  FIGS.  62 - 69   . 
       FIGS.  72 - 74    are various views of the housing  20  of the connector  10  depicted in  FIGS.  70  and  71   .  FIG.  72 A  is bottom perspective view showing the locking feature  20 L of housing  20  configured as a ramp (not numbered) with a ledge (not numbered) as the retaining feature for cooperating with a suitable securing feature of a device. Housing  20  is similar to the housings  20  disclosed herein, but further comprises one or more latch arms  20 LA disposed in a front portion FP of housing  20  as depicted. Moreover, the front opening of passageway  22  is sized for allowing the insertion of ferrule holder  49  from the front end  23  of housing  20  such as shown in the cross-section of  FIG.  73   . Latch arms  20 LA are connected at the front end and cantilevered at the rear end so they can be deflected when ferrule holder  49  is inserted and then spring back to retain the ferrule holder  49  once it is fully-inserted. 
       FIG.  75    is a partially exploded view of the front end of connector  10  prior to the ferrule holder  49  and ferrule  30  being inserted into housing  20 .  FIG.  76    is a cross-sectional view of the front end of the connector  10  after the ferrule holder  49  and ferrule  30  are inserted into housing  20  and retained by latch arms  20 LA. As depicted, latch arms  20 LA have ramp portions for aiding portions of ferrule holder  49  to deflect the latch arms  20 LA outward as the ferrule holder  49  is inserted into housing  20  and then spring back over ferrule holder  49  for retaining the same. 
     Referring to  FIG.  75   , optical fiber  92  of cable  90  is assembled to extend past the front end  23  and resilient member  50  is threaded about optical fiber  92  and then the ferrule holder  49  and ferrule  30  are threaded over optical fiber  92 . Optical fiber  92  may be clamped in a suitable manner through bores  20 C disposed on opposite side of housing  20  as represented by the arrows in  FIG.  76    when ferrule holder  49  is being inserted into housing  20 . Clamping optical fiber  92  inhibits the optical fiber  92  from pushing rearward or buckling as ferrule holder  49  inserted. Ferrule holder  49  is aligned to a suitable rotational position and pushed rearward into housing  20  until retained by latch arms  20 LA as depicted in  FIG.  76   . Optical fiber  92  is secured to ferrule  30  in a suitable fashion and the end face of ferrule  30  is polished. 
     Additionally, ferrule holder  49  may be configured for tuning ferrule  30  relative to housing  20 .  FIG.  77    is a perspective detailed view of the ferrule  30  disposed in ferrule holder  49 . As shown, ferrule holder  49  comprises a plurality of recesses  49 R formed in flange  49 F for tuning of the connector. In this embodiment, flange  49 F has four recesses  49 R allowing four different rotational positions for ferrule holder  49 /ferrule  30 , thereby allowing quadrant tuning.  FIG.  78    is a detailed front end view of the connector  10  showing that the front opening of housing  20  is sized for allowing the insertion of the ferrule holders. Additionally, a portion of the passageway  22  is sized to cooperate with the flange  49 F and allow different rotational positions. Consequently, after measurement of the end face profile of the ferrule  30  or measurement of the insertion loss, the ferrule  30  may be tuned if desired for improving performance such as to a Grade B standard. By way of explanation, the latch arms  20 LA may be deflected outward to release the ferrule holder  49  and then the ferrule holder  49  is rotated to the desired position and inserted back into the housing  20  until it is retained by latch arms  20 LA. Other embodiments of ferrule holder  49  may have other suitable numbers of rotational positions as desired. 
     Other variations of the housing  20  for connectors  10  is also possible.  FIGS.  79  and  79 A  depict perspective view and cross-sectional views of another connector housing that may be used with any of the suitable concepts disclosed. In this embodiment, the rear portion RP is non-round, and has a polygonal cross-section PCS as shown by the cross-section in  FIG.  79 A .  FIG.  79 A  shows that this housing  20  may have a keying feature  20 K which may take any suitable form or may a keying portion  20 KP as desired. Likewise, this housing  20  may use any suitable locking feature  20 L as desired. 
     Although the disclosure has been illustrated and described herein with reference to explanatory embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples can perform similar functions and/or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the disclosure and are intended to be covered by the appended claims. It will also be apparent to those skilled in the art that various modifications and variations can be made to the concepts disclosed without departing from the spirit and scope of the same. Thus, it is intended that the present application cover the modifications and variations provided they come within the scope of the appended claims and their equivalents.