Patent Publication Number: US-2023161123-A1

Title: Active optical cable assemblies

Description:
RELATED APPLICATION(S) 
     This application is a continuation of U.S. patent application Ser. No. 17/322,043, filed May 17, 2021, which claims priority from and the benefit of U.S. Provisional Application Ser. No. 63/027,467, filed May 20, 2020, the entire contents of each of which is incorporated herein by reference in their entirety. 
    
    
     FIELD 
     The present application is directed generally toward telecommunications equipment, and more particularly, active optical cable assemblies and remote radio systems. 
     BACKGROUND 
     Traditional optical assemblies have optical connectors on both ends of the assembly. These assemblies may be connected to a remote radio unit (RRU), remote radio head (RRH) or active antenna at one end and a base band unit (BBU), another RRU, or other telecommunication equipment via a small form-factor pluggable (SFP) optical connector (i.e., the optical assembly is connected to one end of the SFP via an optical connector/adapter and the other end of the SFP (i.e., the copper connection end) may be inserted into the RRU, RRH, etc.) to create an active optical cable assembly. Active optical cables (AOC) represent a cabling technology that accepts the same electrical inputs as a traditional copper cable, but uses optical fiber between connectors. Thus, the SFP converts an optical signal to an electrical signal. Active optical cables use optical-to-electrical conversion on the cable ends to improve speed and distance performance of the cable without sacrificing compatibility with standard electrical interfaces. 
     Generally speaking, mating optical connectors mechanically couple and align the cores of optical fibers so light can pass. The better the connector, the better the optical cleanliness of the connection (i.e., less light is lost due to reflection or misalignment of the optical fibers). The optical connector interface (e.g., on the optical connector of the optical assembly and/or on the optical connector/adapter of the SFP) is very small and delicate (e.g., glass), and is susceptible to dust, scratches, etc. which can affect the optical cleanliness of the connection. Therefore, during installation, a technician must have a proper tool to inspect the ends for a clean and scratch-less optical interface. If the ends are dirty, the technician also must have a cleaning tool and requires that the technician have special skills to perform these tasks. In addition, the technician must also test the optical assembly for damage. Even after inspecting and cleaning the optical interface, in many instances, it is discovered during activation of the RRU that the SFP is defective. Currently, there is not a way for the technician to test the SFP in the field without installing it into the RRU. Thus, there may be a need for an active optical cable assembly that would allow for better optical cleanliness when used with, for example, a remote radio unit. 
     SUMMARY 
     A first aspect of the present invention is directed to an end cap for an active optical cable assembly. The end cap includes an outer protective shell surrounding an inner cavity, the outer protective shell having an open end configured to receive a fixed optical connector of the active optical cable assembly. The inner cavity is sized to fit around the fixed optical connector and configured to form an interference fit therewith. 
     Another aspect of the present invention is directed to an end cap adapted for use with an active optical cable assembly. The end cap includes a main body including one or more sidewalls, a closed end, and an opposing open end, the one or more sidewalls and closed end of the main body defining an inner cavity. The inner cavity is sized and configured to receive a fixed optical connector of the active optical cable assembly inserted through the open end of the main body. 
     Another aspect of the present invention is directed to an active optical cable assembly kit. The kit includes an active optical cable assembly, the active optical cable assembly comprising a fixed active optical connector and a shroud; and an end cap, the end cap including a main body having one or more sidewalls, a closed end, and an opposing open end, the one or more sidewalls and closed end of the main body defining an inner cavity. The inner cavity of the end cap is sized and configured to receive the fixed optical connector of the active optical cable assembly and the main body is configured to engage the shroud of the active optical cable assembly to secure the end cap thereto. 
     It is noted that aspects of the invention described with respect to one embodiment, may be incorporated in a different embodiment although not specifically described relative thereto. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination. Applicant reserves the right to change any originally filed claim and/or file any new claim accordingly, including the right to be able to amend any originally filed claim to depend from and/or incorporate any feature of any other claim or claims although not originally claimed in that manner. These and other objects and/or aspects of the present invention are explained in detail in the specification set forth below. Further features, advantages and details of the present invention will be appreciated by those of ordinary skill in the art from a reading of the figures and the detailed description of the preferred embodiments that follow, such description being merely illustrative of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG.  1    is a photograph of an exemplary fixed active optical connector according to embodiments of the present invention. 
         FIG.  2    is a perspective view of an active optical cable assembly according to embodiments of the present invention. 
         FIG.  3 A  is a perspective view of the active optical cable assembly of  FIG.  1 A  with a removable shroud according to embodiments of the present invention. 
         FIG.  3 B  is a photograph of an exemplary active optical cable assembly according to embodiments of the present invention. 
         FIG.  4 A  is a side view of a removable shroud according to embodiments of the present invention. 
         FIG.  4 B  is a photograph of an exemplary removable shroud according to embodiments of the present invention. 
         FIG.  4 C  is an exploded view of the removable shroud of  FIG.  4 A . 
         FIG.  5 A  is a photograph of an input port to a remote radio unit and mating interface for a removable shroud according to embodiments of the present invention. 
         FIG.  5 B  is a photograph of the input port of  FIG.  5 A  with the fixed active optical connector of  FIG.  1    plugged into the input port. 
         FIG.  6 A  is a photograph of an exemplary active optical cable assembly connected to a remote radio unit according to embodiments of the present invention, wherein the shroud of the assembly is omitted. 
         FIG.  6 B  is a photograph of the active optical cable assembly shown in  FIG.  6 A  with a removable shroud according to embodiments of the present invention. 
         FIG.  7 A  is a perspective view of the active optical cable assembly of  FIG.  2    with an alternative removable shroud according to embodiments of the present invention. 
         FIG.  7 B  is a photograph of an exemplary active optical cable assembly according to embodiments of the present invention. 
         FIG.  8 A  is a side view of a removable shroud according to embodiments of the present invention. 
         FIG.  8 B  is a photograph of an exemplary removable shroud according to embodiments of the present invention. 
         FIG.  9 A  is a photograph of an input port to a remote radio unit, with a standard SFP plugged into the input port, and a mating interface for a removable shroud according to embodiments of the present invention. 
         FIG.  9 B  is a photograph of the input port and mating interface of  FIG.  9 A  with a standard fixed active optical connector of  FIG.  1    prior to being plugged into the input port. 
         FIG.  9 C  is a photograph of the active optical cable assembly of  FIG.  7 B  with the fixed active optical connector plugged into the input port of the remote radio unit. 
         FIG.  10 A  is a side view of an exemplary hybrid cable assembly according to embodiments of the present invention. 
         FIG.  10 B  is an enlarged partial view of the hybrid cable assembly of  FIG.  10 A . 
         FIG.  11 A  is a side view of a fiber optic cable assembly according to embodiments of the present invention. 
         FIG.  11 B  is an enlarged partial view of the fiber optic cable assembly of  FIG.  11 A . 
         FIG.  12 A  is a side view of an end cap for an active optical connector according to embodiments of the present invention. 
         FIG.  12 B  is a perspective view of the end cap of  FIG.  12 A . 
         FIG.  12 C  is a side cross-sectional view of the end cap of  FIGS.  12 A- 12 B . 
         FIG.  13 A  is a photograph of an exemplary alternative removable shroud (exploded) according to embodiments of the present invention. 
         FIG.  13 B  is an enlarged photograph of the main body of the removable shroud of  FIG.  13 A . 
         FIG.  13 C  is a photograph of an exemplary active optical cable assembly with the removable shroud of  FIG.  13 A  according to embodiments of the present invention. 
         FIG.  13 D  is a photograph of the active optical cable assembly of  FIG.  13 C . 
         FIG.  14 A  is a photograph of an exemplary alternative removable shroud (exploded) according to embodiments of the present invention. 
         FIG.  14 B  is a photograph of an exemplary active optical cable assembly with the removable shroud of  FIG.  14 A  according to embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. Like numbers refer to like elements throughout and different embodiments of like elements can be designated using a different number of superscript indicator apostrophes (e.g.,  10 ′,  10 ″,  10 ′″). 
     In the figures, certain layers, components, or features may be exaggerated for clarity, and broken lines illustrate optional features or operations unless specified otherwise. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. The sequence of operations (or steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     As used herein, phrases such as “between X and Y” and “between about X and Y” should be interpreted to include X and Y. As used herein, phrases such as “between about X and Y” mean “between about X and about Y.” As used herein, phrases such as “from about X to Y” mean “from about X to about Y.” 
     Pursuant to embodiments of the present invention, active optical cable assemblies are provided that may enhance the optical cleanliness of an optical connection. Active optical cable and remote radio unit systems are also provided herein. Embodiments of the present invention will now be discussed in greater detail with reference to  FIGS.  1 - 14 B . 
     Referring now to the drawings, an active optical cable assembly  10  according to embodiments of the present is shown in  FIGS.  1 - 2   . As can be seen in  FIGS.  1 - 2   , the cable assembly  10  may include a fiber optic cable  14 . In some embodiments, the fiber optic cable  14  may be a ruggedized fiber optic cable. At one end of the ruggedized fiber optic cable  14 , a fixed active optical connector (with transceiver)  12  (e.g., an active optical connector) may be integrated with the cable  14 . The fixed optical connector  12  is configured to be inserted into (i.e., plugged into) and received by an input port  32  of a remote radio unit  30  (see, e.g.,  FIGS.  5 A- 5 B ,  FIGS.  6 A- 6 B , and  FIGS.  9 A- 9 C ). For example, in some embodiments, the fixed optical connector  12  may be a small form-factor pluggable (SFP) optical connector. As discussed above, the SFP converts an optical signal to an electrical signal. Integrating an SFP optical connector  12  into the optical assembly  10  of the present invention eliminates the optical connector interface issue described above. Thus, no special tools are required to test or clean the optical connectors, thereby helping to reduce installation time and costs associated therewith. In addition, because the non-integrated end of the SFP optical connector  12  is an electrical contact, the optical assembly  10  is easier to handle by a technician (i.e., not as delicate as an optical connector interface). Moreover, by eliminating the connector (optical assembly) to connector (SFP) optical connection, insertion loss (IL) and return loss (RL) may be improved, thereby increasing optical cleanliness. Furthermore, the active optical cable assembly  10  of the present invention (i.e., having an integrated SFP optical connector  12 ) can be tested prior to installation, thereby eliminating a technician discovering that an SFP is defective during RRU activation. 
     In some embodiments, the fixed optical connector  12  may have a pull tab  17  attached thereto. The pull tab  17  may be used by a technician to grip when removing (i.e., pulling) the fixed optical connector  12  from the input port  32  of the remote radio unit  30 . In some embodiments, the pull tab  17  may also be used to help secure or lock the fixed connector  12  in place within the remote radio unit  30  (see, e.g.,  FIGS.  13 A- 13 D ). 
     The active optical cable assembly  10  of the present invention may further include a main cable assembly  11 . In some embodiments, the main cable assembly  11  may comprise one or more fiber optic cables  16  with active optical connectors  18  (i.e., an optical cable assembly) (see also, e.g.,  FIGS.  11 A- 11 B ). In some embodiments, each fiber optic cable  14 ,  16  (i.e., the ruggedized fiber optic cable  14  and the one or more fiber optic cables  16  of the cable assembly  11 ) includes at least one optical fiber (not shown) that may be spliced together at a splice transition area (i.e., within a protective enclosure  15 ) (see, e.g.,  FIGS.  2 ,  3 A- 3 B,  7 A- 7 B,  10 A- 10 B, and  11 A- 11 B ). In some embodiments, the optical fibers may be fusion spliced together. In some embodiments, the optical fibers may comprise ribbonized optical fibers  62  (see, e.g.,  FIGS.  11 A- 11 B ). 
     As shown in  FIGS.  3 A- 3 B , in some embodiments, the active optical cable assembly  10  may further include a removable shroud  20 . The shroud  20  is configured to surround at least a portion of the fixed optical connector  12 . For example, the shroud  20  may surround a portion of the fixed optical connector  12  that extends outwardly from the remote radio unit  30  when the fixed connector  12  is plugged into the remote radio unit  30  (see, e.g.,  FIG.  6 B ). 
     The removable shroud  20  is further shown in  FIGS.  4 A- 4 C . As illustrated in  FIGS.  4 A- 4 C , the shroud  20  includes a tubular main body  22 . At one end, the main body  22  comprises a locking section  26  with a mating end  26   a . A threaded section  27  resides at the opposing end of the main body  22 . The removable shroud  20  further includes a locking mechanism  24  that is slidable along the main body  22 . A biasing member  23  (e.g., a spring) is coupled to the main body  22  of the shroud  20  and resides between the locking section  26  and the locking mechanism  24 . As described in further detail below, the locking mechanism  24 , locking section  26 , and biasing member  23  may function together as a “push-pull” latching mechanism to secure the shroud  20  to a remote radio unit  30 . In some embodiments, the shroud  20  also includes a coupling nut  28  and coupling gasket  28   a . The coupling nut  28  is configured to be screwed onto the threaded section  27  of the main body  22 . In some embodiments, the shroud  20  may further comprise a sealed end cap  25 . 
     The locking section  26  (and mating end  26   a ) of the removable shroud  20  may be configured to secure the shroud  20  to the remote radio unit  30  (i.e., after a fixed active optical connector  12  has been plugged into an input port  32 ). In some embodiments, the shroud  20  may be configured to be secured to a mating interface  34  corresponding to an input port  32  of the remote radio unit  30  (see, e.g.,  FIG.  6 B ). For example, in some embodiments, the shroud  20  may form a bayonet connection with the mating interface  34 . As shown in  FIGS.  5 A- 5 B , the mating interface  34  may comprise an annular flange  35 . In some embodiments, a pair of arms  36  may extend outwardly from the annular flange  35 . Each arm may comprise a securing feature  38 , such as, a snap-fit feature or the like. In some embodiments, to secure the shroud  20  to the remote radio unit  30 , the mating end  26   a  is aligned with the mating interface  34  such that the locking section  26  is located inside the annular flange  35  and between the outwardly extending arms  36 . Next, the locking mechanism  24  is pushed (or slid) along the main body  22  toward the locking section  26  (compressing the biasing member  23 ) until the locking mechanism  24  engages the securing feature  38  of the arms  36  (i.e., the arms  36  are between the locking section  26  and the locking mechanism  24 ). The locking mechanism  24  is then rotated to lock the securing feature  38  within the locking mechanism  24 , thereby securing the shroud  20  to the remote radio unit  30 . Once the shroud  20  is secured to the remote radio unit  30 , the coupling nut  28  may be screwed onto the threaded section  27  of the main body  22 . As the coupling nut  28  is tightened, the coupling gasket  28   a  is squeezed against the ruggedized cable  14 , thereby creating a seal between the removable shroud  20  and the cable  14 . 
     To remove the shroud  20  from the remote radio unit  30 , the coupling nut  28  is unscrewed from the threaded section  27  and the locking mechanism  24  is rotated in an opposite direction to release the securing feature  38  from the locking mechanism  24 . Once released, the biasing member  23  pushes the locking mechanism  24  away from the locking section  26 , thereby allowing the shroud  20  to be pulled away from the mating interface  34  of the remote radio unit  30 . 
     In some embodiments, the mating end  26   a  of the shroud  20  may be configured to form an interference fit (e.g., via gasket compression) with the mating interface  34  of the remote radio unit  30 . In other embodiments, the shroud  20  may comprise threads that correspond to threads on the mating interface  34 , allowing the shroud  20  to be secured (i.e., screwed) onto the remote radio unit  30 . The shroud  20  may help to enhance or increase optical cleanliness by providing protection to the optical connection between the fixed optical connector  12  and the remote radio unit  30  (e.g., protecting from dust and/or environmental conditions). In addition, in some embodiments, the shroud  20  may comprise one or more features configured to protect the fixed optical connector  12  from vibration and/or mechanical shock. For example, in some embodiments, the shroud  20  may be molded such that the interior of the shroud  20  corresponds to the shape of the fixed connector  12  which helps to hold the fixed connector  12  in place. In some embodiments, the vibration reduction and/or alignment feature may be a gasket or slotted spring feature. In some embodiments, the removable shroud  20  may be formed from a polymeric material, such as polyurethane, rubber, acrylonitrile butadiene styrene (ABS), or the like. 
     Referring to  FIGS.  7 A- 7 B  and  FIGS.  8 A- 8 B , according to embodiments of the present invention, an alternative removable shroud  200  that may be used with the active optical cable assembly  10  is illustrated. As shown in  FIGS.  7 A- 8 B  and  FIGS.  8 A- 8 B , in some embodiments, at least a portion of the shroud  200  may be formed from a metallic material. The metallic portion  202  of the shroud  200  may be configured to surround at least a portion of the fixed optical connector  12  and be secured to the remote radio unit  30  (e.g., by mating end  202   a ). In some embodiments, the shroud  200  may further comprise a polymeric strain relief section  204 . The polymer strain relief section  204  may be configured to bend with the fiber optic cable  14 , thereby relieving strain from the removable shroud  200  and fixed optical connector  12  within the shroud  200 . The strain relief section  204  of the shroud  200  may further comprise a coupling nut  206  configured to threaded with the metallic portion  202 . Similar to the shroud  20  described above, as the coupling nut  206  is threaded with the metallic portion  202 , a coupling mechanism  203  squeezes a coupling gasket  203   a  against the ruggedized cable  14 , thereby creating a seal between the shroud  200  and the cable  14 . 
       FIGS.  9 A- 9 C  illustrate a remote radio unit  30  having a different mating interface  34 ′. As shown in  FIGS.  9 A- 9 B , instead of a pair of arms  36  with a securing feature  38 , in some embodiments, the mating interface  34 ′ may have an extended annular flange  35 ′. The extended annular flange  35 ′ may comprise one or more slots  38 ′, each having an open end  38   a ′. In some embodiments, to secure the shroud  200  to a remote radio unit  30  having mating interface  34 ′, the mating end  202   a  of the metallic portion  202  is aligned with the extended annular flange  35 ′ such that corresponding securing features (not shown) within the mating end  202   a  align with each open end  38   a ′ of the slots  38 ′. The metallic portion  202  is rotated to lock each securing feature within a respective slot  38 ′, thereby securing the removable shroud  200  to the remote radio unit  30 . 
     To remove the shroud  200  from the remote radio unit  30 , the coupling nut  206  is unscrewed from the metallic portion  202  and the metallic portion  202  is rotated in an opposite direction to release the securing features from the slots  38 ′. Once released, the shroud  200  may be pulled away from the mating interface  34 ′ of the remote radio unit  30 . 
     Similar to the removable shroud  20  described above, the removable shroud  200  may help to enhance or increase optical cleanliness by helping to protect the optical connection between the fixed optical connector  12  and the remote radio unit  30 . In some embodiments, the shroud  200  may be configured to form an interference fit with the mating interface  34  of the remote radio unit  30 . In other embodiments, the shroud  200  may comprise threads that correspond to threads on the mating interface  34 , thereby allowing the shroud  200  to be secured (i.e., screwed) onto the remote radio unit  30 . In addition, in some embodiments, the shroud  200  may comprise one or more features configured to protect the fixed optical connector  12  from vibration and/or mechanical shock. The removable shrouds  20 ,  200  also provide protection against environmental conditions such as rain, snow, etc. 
     Referring now to  FIGS.  10 A- 10 B  and  FIGS.  11 A- 11 B , in some embodiments, the main cable assembly  11  may be a hybrid cable assembly  40  ( FIGS.  10 A- 10 B ) or fiber optic cable assembly  50  ( FIGS.  11 A- 11 B ). As shown in  FIGS.  10 A- 10 B , the hybrid cable assembly  40  includes a hybrid cable  44  that may comprise optical cables (i.e., optical fibers)  16  with optical connectors  18  and power conductors (e.g., copper conductors)  42 . The hybrid cable assembly  40  may include one or more transition or breakout sections (i.e., protective enclosures)  45  allowing the hybrid cable assembly  40  to breakout into two or more active optical cable assemblies  10 . For example, as shown in  FIGS.  10 A- 10 B , the hybrid cable assembly  40  may be broken out into two active optical cable assemblies  10  with a central power cable  46 . As discussed herein, in some embodiments, the fiber optic cables  14 ,  16  include at least one optical fiber (not shown) that may be spliced together at a splice transition area (i.e., within the protective enclosures  15 ,  45 ). In some embodiments, the optical fibers may be fusion spliced together. 
     As shown in  FIGS.  11 A- 11 B , the fiber optic cable assembly  50  includes a fiber optic cable  54  that may comprise ribbonized optical fibers  62 . The fiber optic cable assembly  50  may include a transition or breakout section  55  allowing the fiber optic cable assembly  50  to breakout into two or more active optical cable assemblies  10  (with respective fixed optical connectors  12 ). The fiber optic cable assembly  50  may include any number of active optical cable assemblies  10 . For example, as shown in  FIG.  11 A , the fiber optic cable assembly  50  may include six active optical cable assemblies  10  with fixed optical connectors  12  (i.e.,  12 - 1  through  12 - 6 ). As shown in  FIG.  11 B , in some embodiments, the optical fibers  62  may be spliced together at a splice transition area  64 . In some embodiments, the optical fibers  62  may be fusion spliced together. In some embodiments, the splice transition area  64  (e.g., fusion spliced) may be encapsulated by a protective enclosure  60 , such as an armored furcation tube. The protective enclosure  60  may be secured to the fiber optic cable  54  via an adhesive heat-shrink tube or over-molded polymer  66 . 
     Referring now to  FIGS.  12 A- 12 C , an end cap  70  for the active optical cable assembly  10  of the present invention is illustrated. The end cap  70  is configured to fit around the fixed active optical connector  12  and protect the connector  12  (and transceiver) during, for example, shipment and/or storage (e.g., from dust and/or environmental conditions) before the connector  12  is plugged into a remote radio unit  30 . The end cap  70  comprises an outer protective shell  72  surrounding an inner cavity  74  with an open end. The open end is configured to allowed the end cap  70  be slid onto the fixed optical connector  12 . In some embodiments, the inner cavity  74  is configured to form an interference fit with the fixed optical connector  12 . For example, as shown in  FIGS.  12 B- 12 C , an interior gasket  73  may be molded such that the inner cavity  74  corresponds with the shape of the fixed connector  12  (e.g., rectangular in shape), allowing the end cap  70  to form an interference fit with the active optical connector  12 , and thereby helping to reduce vibration and/or mechanical shock on the optical connector  12 . 
     As shown in  FIGS.  12 A- 12 C , in some embodiments, the end cap  70  may have one or more additional securing features  76 . The securing features  76  may extend outwardly in an axial direction from the open end of the end cap  70 . The securing features  76  may be configured to secure the end cap  70  to the removable shroud  20 ,  200  described herein. Any number of known securing features  76  may be used with the end cap  70 . For example, in some embodiments, the securing feature  76  may be a snap-fit feature that can be deflected radially inward until a protrusion  76   a , for example, engages with a corresponding feature of the removable shroud  20 ,  200 . 
     In some embodiments, the end cap  70  may further comprise an annular gasket  75  adjacent to the open end. The annular gasket  75  may help to provide a water-tight seal, for example, between the end cap  70  and the removable shroud  20 ,  200 . In some embodiments, the end cap  70  may further include an aperture  77 . The aperture  77  may be used during storage and/or may be used to help remove the end cap  70  from a fixed optical connector  12 . 
     Referring now to  FIGS.  13 A- 13 D , an alternative removable shroud  300  according to embodiments of the present invention is illustrated. As shown in  FIGS.  13 A- 13 C , in some embodiments, the shroud  300  has a main body  302 . The main body  302  has an inner cavity  304  configured to fit at least a portion of an active optical connector  12 ,  12 ′ (see, e.g.,  FIG.  13 B ). In some embodiments, the inner cavity  304  is configured to form an interference fit with at least a portion of an active optical connector  12 ,  12 ′. The shroud  300  further has a latching mechanism  306  that is pivotably coupled to the main body  302 . At one end of the latching mechanism  306  is a latch (or hook)  306   a  configured to secure the shroud  300  to a remote radio unit  30 . At the other end of the latching mechanism is a pull tab  317 . To secure the shroud  300  to a remote radio unit  30 , the main body  302  is slid over the active optical connector  12 ,  12 ′ (i.e., already plugged into the input port  32 ,  32 ′ of the remote radio unit  30 ) and the pull tab  317  is pushed toward the main body  302  which pivots the latch  306  to lock with a corresponding securing feature (not shown) on the remote radio unit  30 , thereby securing the shroud  300  to the remote radio unit  30 . 
     The shroud  300  further includes a coupling nut  308  configured to be threaded with a threaded section  302   a  of the main body  302 . Similar to the shrouds  20 ,  200  described herein, as the coupling nut  308  is threaded with the threaded section  302   a , a coupling mechanism  303  squeezes a coupling gasket  305  against the ruggedized cable  14 , thereby creating a seal between the shroud  300  and the cable  14 .  FIG.  13 D  shows the removable shroud  300  in combination with an active optical cable assembly  10  of the present invention. 
     Referring now to  FIGS.  14 A- 14 B , an alternative removable shroud  400  according to embodiments of the present invention is illustrated. Removable shroud  400  is similar to removable shroud  20  described herein. Thus, properties and/or features of the shroud  400  may be described above in references to  FIGS.  4 A- 4 C  and duplicate discussion thereof may be omitted herein for the purposes of discussing  FIGS.  14 A- 14 B . 
     As shown in  FIG.  14 A , the shroud  400  includes a tubular main body  402 . At one end, the main body  402  comprises a locking section  406  with a mating end  406   a . A threaded section  402   a  resides at the opposing end of the main body  402 . The shroud  400  further includes a locking mechanism  404  that is slidable along the main body  402 . A biasing member (not shown) is coupled to the main body  402  and resides between the locking section  406  and the locking mechanism  404 . Similar to shroud  20  described herein, the locking mechanism  404 , locking section  406 , and biasing member may function together as a “push-pull” latching mechanism to secure the removable shroud  400  to a remote radio unit  30 . In some embodiments, the shroud  400  also includes a coupling nut  408 , coupling mechanism  407 , and coupling gasket  405 . The coupling nut  408  is configured to be screwed onto the threaded section  402   a  of the main body  402 . Similar to the shrouds  20 ,  200 ,  300  described herein, as the coupling nut  408  is threaded with the threaded section  402   a , the coupling mechanism  407  squeezes the coupling gasket  405  against the ruggedized cable  14 , thereby creating a seal between the shroud  400  and the cable  14 .  FIG.  14 B  shows the removable shroud  400  in combination with an active optical cable assembly  10  of the present invention. 
     The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.