Patent Publication Number: US-2015063756-A1

Title: System for terminating one or more optical fibers and fiber optic connector holder used in same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. Nos. 61/871,396 and 61/871,558, both of which were filed on Aug. 29, 2013, and both of whose content is relied upon and incorporated herein by reference in its entirety. This application also claims the benefit of priority under 35 U.S.C. §120 of U.S. patent application Ser. No. 14/070,876, filed on Nov. 4, 2013, the content of which is also relied upon and incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The disclosure relates generally to optical fiber connectivity and more particularly to systems and methods for terminating one or more optical fibers. 
     Optical fibers are useful in a wide variety of applications, including the telecommunications industry for voice, video, and data transmission. Due at least in part to extremely wide bandwidth and low noise operation provided by optical fibers, the variety of applications in which optical fibers are being used is continuing to increase. For example, optical fibers no longer serve merely as a medium for long distance signal transmission, but are being increasingly routed directly to the home and, in some instances, directly to a desk or other work location. 
     In a system that uses optical fibers, there are typically many locations where one or more optical fibers are optically coupled to one or more other optical fibers. The optical coupling is often achieved by fusion splicing the optical fibers together or by terminating the optical fibers with fiber optic connectors. Fusion splicing has the advantage of providing low attenuation, but can make reconfiguring the system difficult, typically requires expensive tools to perform the operation, and involves additional hardware to protect the spliced area after the operation. Termination, on the other hand, provides the flexibility to reconfigure a system by allowing optical fibers to be quickly connected to and disconnected from other optical fibers or equipment. 
     One challenge associated with termination is making sure that the fiber optic connectors do not significantly attenuate, reflect, or otherwise alter the optical signals being transmitted. Performing termination in a factory setting (“factory termination”) is one way to address this challenge. The availability of advanced equipment and a controlled environment allow connectors to be installed on the end portions of optical fibers in an efficient and reliable manner. In many instances, however, factory termination is not possible or practical. For example, the lengths of fiber optic cable needed for a system may not be known before installation. Terminating the cables in the field (“field termination”) provides on-site flexibility both during initial installation and during any reconfiguring of the system, thereby optimizing cable management. Because field termination is more user-dependent, fiber optic connectors have been developed to facilitate the process and help control installation quality. 
     One example of such a development is the UNICAM® family of field-installable fiber optic connectors available from Corning Cable Systems LLC of Hickory, N.C. UNICAM® fiber optic connectors include a number of common features, including a mechanical splice between a preterminated fiber stub (“stub optical fiber”) and an optical fiber from the field (“field optical fiber”), and are available in several different styles of connectors, such as ST, SC, and LC fiber optic connectors.  FIGS. 1A and 1B  illustrate an exemplary fiber optic connector  10  belonging to the UNICAM® family of fiber optic connectors. A brief overview of the fiber optic connector  10  will be provided for background purposes. It should be noted, however, that the systems and methods disclosed herein are applicable to verifying the continuity of an optical coupling between any pair of interconnected optical fibers, and more particularly, between a field optical fiber and an optical fiber of any fiber optic connector, including single-fiber or multi-fiber connectors involving mechanical or fusion splices. 
     As shown in  FIGS. 1A and 1B , the fiber optic connector  10  includes a ferrule  12  received in a ferrule holder  16 , which in turn is received in a connector housing  19 . The ferrule  12  defines a lengthwise, longitudinal bore for receiving a stub optical fiber  14 . The stub optical fiber  14  may be sized such that one end extends outwardly beyond a rear end  13  of the ferrule  12 . The fiber optic connector  10  also includes a pair of opposed splice components  17 ,  18  within the ferrule holder  16 , a cam member  20  received over a portion of the ferrule holder  16  that includes the splice components  17 ,  18 , a spring retainer  22  attached or otherwise held in place relative to the connector housing  19 , and a spring  21  for biasing the ferrule holder  16  forwardly relative to the spring retainer  22  and connector housing  19 . At least one of the splice components  17 ,  18  defines a lengthwise, longitudinal groove for receiving and aligning the end portion of the stub optical fiber  14  and an end portion of a field optical fiber  15  on which the fiber optic connector  10  is to be mounted. An index-matching material (e.g., index-matching gel) may be provided within this groove for reasons mentioned below. 
     To allow the fiber optic connector  10  to be mounted on the field optical fiber  15 , the splice components  17 ,  18  are positioned proximate the rear end  13  of the ferrule  12  such that the end portion of the stub optical fiber  14  extending rearwardly from the ferrule  12  is disposed in the groove defined by the splice components  17 ,  18 . The end portion of the field optical fiber  15  can be inserted through a lead-in tube (not shown in  FIGS. 1A and 1B ) and into the groove defined by the splice components  17 ,  18 . By advancing the field optical fiber  15  into the groove defined by the splice components  17 ,  18 , the end portions of the stub optical fiber  14  and the field optical fiber  15  make physical contact and establish an optical connection or coupling between the field optical fiber  15  and the stub optical fiber  14 . The index-matching material (e.g., index-matching gel) provided within the groove surrounds this optical connection to help reduce losses in optical signals that are transmitted between the filed optical fiber  15  and stub optical fiber  14 . 
     The splice termination of the fiber optic connector  10  is completed as illustrated in  FIG. 1B  by actuating the cam member  20 , which engages a keel portion of the lower splice component  18  to bias the splice components  17 ,  18  together and thereby secure the end portions of the stub optical fiber  14  and the field optical fiber  15  relative to the groove defined by the splice components  17 ,  18 . This step is typically completed using a specially-designed installation tool (a known example is mentioned below). The cable assembly may then be completed, for example, by strain relieving a buffer  25  of the field optical fiber  15  to the fiber optic connector  10  in a known manner. 
       FIGS. 2-4  illustrate an installation tool  30  that is an example of those offered by Corning Cable Systems for mounting the UNICAM® family of fiber optic connectors upon the end portion of a field optical fiber. Similar to the description above for the fiber optic connector  10 , a brief overview will be provided for background purposes with the understanding that the systems and methods disclosed later herein are applicable to other types of installation tools. Indeed, as will be apparent, the systems and methods disclosed later herein may be applicable to any installation tool for terminating one or more optical fibers with a fiber optic connector. 
     The installation tool  30  includes a body or housing  32  having an actuation assembly  33  and cradle or carrier  36 . The cradle  36  is slidable along guide rails  38  inside the body  32  and normally biased toward the actuation assembly  33 , as shown in  FIG. 3 . Prior to inserting a fiber optic connector into the installation tool  30 , the cradle  36  is moved away from the actuation assembly  33  (i.e., to the right in the example of  FIG. 3 ). This movement may be achieved by pressing a load button  40 , which is operably coupled to the cradle  36  through mechanical linkages (not shown) within the body  32 . With the load button  40  depressed ( FIG. 4 ), a user may place a fiber optic connector  10  into the space between the actuation assembly  33  and cradle  36 , and subsequently move a lead-in tube  26  of the fiber optic connector  10  axially through a camming member or wrench  34  of the actuation assembly  33  until the cam member  20  is seated in the camming member  34 . At this point, the lead-in tube  26  extends beyond crimp arms  44  that are positioned next to the actuation assembly  33 . Before inserting a field optical fiber  15  into the lead-in tube  26 , the load button  40  is released so that the cradle  36  moves back toward the actuation assembly  33  until the front portion of the fiber optic connector  10  is seated in a U-shaped cutout  42  on the cradle  36 . A visual fault locator (VFL) assembly  46 , the purpose of which will be briefly described below, is also slid toward the fiber optic connector  10  before closing a lid or cover  48  of the installation tool  30  and completing the termination process. 
     The field optical fiber  15  is eventually inserted into the back of the lead-in tube  26  of the fiber optic connector  10  until it abuts the stub optical fiber  15  ( FIGS. 1A and 1B ) within the splice components  17 ,  18 . A user then actuates the cam member  20 , for example by pressing a cam button  50  operably coupled to the camming member  34  by mechanical linkages (not shown), to bias the splice components  17 ,  18  together and thereby secure the stub optical fiber  14  and field optical fiber  15  between the splice components  17 ,  18 . At this point the VFL assembly  46  may be used to check the splice connection between the stub optical fiber  14  and field optical fiber  15 . The VFL assembly  46  includes an adapter  54 , a coupler  60 , a jumper (not shown; hidden within the installation tool  30 ), and an optical power generator (also hidden from view) in the form of a Helium Neon (HeNe) laser diode. The adapter  54  is an interchangeable component so that the VFL assembly can be used with different types/styles of fiber optic connectors. For example, as shown in  FIGS. 5A and 5B , one adapter  54 A may be provided to interface with LC-style connectors, which have a 1.25 mm-diameter ferrule. Another adapter  54 B may be provided to interface with ST and SC-style connectors, both of which have 2.5 mm-diameter ferrules. Corning Cable Systems LLC also offers an adapter configured to interface with MTP-style connectors in some versions of the company&#39;s UNICAM® installation tool. 
     The adapters  54 A,  54 B and other components of the VFL assembly  46  are not the focus of this disclosure. Thus, the Corning Cable Systems LLC system/method for verifying an acceptable splice termination, which is commonly referred to as the “Continuity Test System” (CTS), and the combined functionality of the gas laser and jumper, which are commonly referred to as a “Visual Fault Locator” (VFL), will not be further described herein. Reference can instead be made to U.S. Pat. No. 8,094,988, for example, to obtain a more complete understanding of how the installation tool  30  advantageously incorporates continuity testing. Once an acceptable splice termination is verified, the crimp arms  44  are actuated by rotating a crimp knob  52  to secure the lead-in tube  26  onto the field optical fiber  15 . 
     Although the installation tool  30  greatly facilitates the process of mounting the fiber optic connector  10  on the end portion of the field optical fiber  15 , there remains room for improvement. For example, an inexperienced user may not immediately appreciate how to properly orient the fiber optic connector  10  when loading the installation tool  30 . Because the connector housing  19  may have the same general shape on both ends (e.g., square), the user may accidentally believe that the U-shaped cutout  42  of the cradle  36  accommodates the rear end of the fiber optic connector  10  rather than the front end. Even if a user does orient the fiber optic connector  10  correctly, he or she may have questions about how far to insert the lead-in tube  26  through the camming member  34  and crimp arms  44 . Consulting user manuals typically clears up any misconceptions or confusion, but all users may not be this diligent. 
     Therefore, an installation tool that addresses these and other challenges would be desirable. 
     SUMMARY 
     One embodiment of the disclosure relates to a system for terminating one or more optical fibers. The system comprises a fiber optic connector, a connector holder, and an installation tool. The fiber optic connector has a ferrule and a connector housing in which the ferrule is at least partially positioned. The connector holder receives at least a portion of the connector housing and has a base portion that defines a bottom surface of the connector holder. The installation tool includes a body, which in turn includes a connector holding area configured to receive and cooperate with the base portion of the connector holder to securely position the fiber optic connector on the body. 
     Additional embodiments of the disclosure relate to connector holders like the connector holder mentioned above, but not limited to use in systems for terminating one or more optical fibers. In other words, some embodiments relate to connector holders used in connection with tools or equipment that may not be installation tools. A stand-alone test system for checking the splice connection in a mechanical splice fiber optic connector is one example of such a tool. In some of the additional embodiments, a connector holder includes a base portion and a holding portion extending from the base portion. The base portion defines a bottom surface of the connector holder and is shaped so that the bottom surface has a rotationally asymmetrical profile. The holding portion extends from the base portion and defines a receptacle configured to receive the fiber optic connector. 
     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. Indeed, it is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understand the nature and character of the claims. 
     The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain principles and operation of the various embodiments. Persons skilled in the technical field of fiber optic connectors will appreciate how features and attributes associated with embodiments shown in one of the drawings may be applied to embodiments shown in others of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a lengthwise cross-sectional view of one example of a fiber optic connector being mounted on a field optical fiber by inserting the field optical fiber through a rear end of the fiber optic connector; 
         FIG. 1B  is a lengthwise cross-sectional view similar to  FIG. 1A , but showing the field optical fiber mechanically spliced to a stub optical fiber within the fiber optic connector by means of splice components that have been moved to an actuated position by a cam member; 
         FIG. 2  is a perspective of one example of an installation tool for terminating a field optical fiber with a fiber optic connector, such as the fiber optic connector of  FIGS. 1A and 1B , wherein the installation tool is shown in a closed configuration; 
         FIG. 3  is a perspective view of the installation tool of  FIG. 2  in an open configuration prior to use; 
         FIG. 4  is a perspective view of the installation tool of  FIG. 2  in an open configuration, wherein a fiber optic connector is shown being loaded into the installation tool; 
         FIGS. 5A and 5B  are perspective views of adapters used in the installation tool of  FIG. 2 ; 
         FIG. 6  is a perspective view of one embodiment of a system for terminating one or more optical fibers; 
         FIG. 7  is a perspective view of an example of a fiber optic connector and connector holder that may be used in the system of  FIG. 6  and other embodiments of such systems; 
         FIG. 8  is a perspective view of an example of a connector holder for an LC-type fiber optic connector; 
         FIG. 9  is a perspective view of an example of a connector holder for an ST-type fiber optic connector; 
         FIG. 10  is a perspective view of an example of a connector holder for an SC-type fiber optic connector; 
         FIG. 11  is a perspective view of another embodiment of an installation tool for terminating an optical fiber with a fiber optic connector, prior to the fiber optic connector being loaded into the installation tool; 
         FIG. 12  is a perspective view of the installation tool of  FIG. 11  after an LC-type fiber optic connector has been loaded into the installation tool using the connector holder of  FIG. 8 ; 
         FIG. 13  is a perspective view of the installation tool of  FIG. 11  after moving an adapter to interface with the fiber optic connector, wherein the adapter is part of a system for checking a splice connection in the fiber optic connector; and 
         FIGS. 14A-14D  are perspective views of a portion of an embodiment of a test system for checking the splice connection between a stub optical fiber and field optical fiber within a fiber optic connector. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments will be further clarified by the following examples, which relate to systems for terminating one or more optical fibers with a fiber optic connector and installation tools and connector holders used in such systems. The fiber optic connector may include one or more stub optical fibers to which one or more field optical fibers are optically coupled. To this end, the examples described below may be used in connection with the fiber optic connector  10  ( FIGS. 1A and 1B ). Reference can be made to the background section above for a complete description of the fiber optic connector  10 , including how the cam member  20  is configured to the bias the splice components  17 ,  18  together to secure the field optical fiber  15  relative to the stub optical fiber  14  and thereby establish a mechanical splice connection. However, as noted in the background section, the examples disclosed herein may also be applicable to systems that involve other fiber optic connector designs. This includes systems for fiber optic connector designs that do not involve a mechanical splice connection. In such systems, the one or more optical fibers that are terminated may extend to a mating surface of the fiber optic connector or a lens formed on such a mating surface. Therefore, any references to the fiber optic connector  10  below are merely to facilitate discussion. 
     With this in mind, one embodiment of a system  100  for terminating one or more optical fibers will now be described with reference to  FIG. 6 . The system  100  includes an installation tool  130  similar the installation tool  30  such that the same reference numbers are used in the  FIG. 6  to refer to elements corresponding to those discussed with respect to the installation tool  30 . Only the differences between the installation tools  30  and  130  will be described below. The system  100  also includes the fiber optic connector  10  (again, which is merely an example of a fiber optic connector) and a connector holder  132  (alternatively referred to as a “handle” or “handler”) for supporting the fiber optic connector  10  on the body  32  of the installation tool  130 . This aspect of the system  100  will be described below as well. 
     In general, the connector holder  132  receives at least a portion of the connector housing  19  ( FIGS. 1A and 1B ) so that the connector holder  132  can be mounted on the fiber optic connector  10 . This step may be done by the manufacturer such that the connector holder  132  and the fiber optic connector  10  are pre-assembled for end users. Alternatively, the connector holder  132  and fiber optic connector  10  may be provided as separate components for an end user to assemble. The connector holder  132  includes a base portion  134  ( FIG. 7 ) defining a bottom surface  136  of the connector holder  132 . The body  32  of the installation tool  130  includes a carrier or other structure that defines a connector holding area  138  configured to received and cooperate with the base portion  134  of the connector holder  132  to securely position the fiber optic connector  10  on the body  32 . The connector holding area  138  in the embodiment shown is in the form of a recess or receptacle having a shape corresponding to the shape of the base portion  134 . An element like the cradle  36  ( FIGS. 3 and 4 ) on the installation tool  30  is no longer necessary. In other words, the connector holding area  138  and connector holder  19  may be used instead of or in addition to the cradle  36  to securely position the fiber optic connector  10  relative to an actuation assembly  140  of the installation tool  130 . 
       FIG. 6  illustrates the actuation assembly  140  being configured so that the fiber optic connector  10  can be loaded into the installation tool  130  prior to actuation and unloaded from the installation tool  130  after actuation along the same path of movement (e.g., in a vertical direction). The actuation assembly  140  effectively has an “always open” pathway perpendicular to a termination axis that is defined when the fiber optic connector  10  is loaded into the installation tool  130 . The always open pathway is due to a camming member  142  having a unique configuration and moving in a particular manner relative to the body  32 . These and other details relating to such an actuation assembly are fully described in U.S. Provisional Patent Application No. 61/871,558, entitled “FIBER OPTIC CONNECTOR INSTALLATION TOOL” and filed on Aug. 29, 2013, which is herein incorporated by reference in its entirety. Other configurations of the actuating assembly  140  will be appreciated by persons skilled in optical connectivity, including configurations like those in the UNICAM® installation tools previously or currently offered by Corning Cable Systems LLC (including the actuation assembly  33  discussed above for the installation tool  30 ). 
       FIG. 6  also illustrates various indicia provided on the body of the installation tool  130 . In particular, numbers may be provided on the installation tool  130  proximate portions or components of the installation tool  130  that are associated with steps performed when using the installation tool  130  to terminate an optical fiber. The portions or components may be numbered sequentially, i.e., in the order in which they require action or attention when using the installation tool  130 . By doing so, the installation tool  130  helps guide a user through the termination process to facilitate performing the right steps in the right order, thereby reducing or eliminating confusion and increasing the likelihood of proper operation (and, therefore, a successful termination). This “follow the numbers” feature may also make it easier for a user to recall the correct order of operations during subsequent uses of the installation tool  130 . The connector receiving area  138  and connector holder  132  may be provided with numbers as part of the sequential numbering scheme. Alternatively or additionally, other indicia may be provided on the connector receiving area  138  and/or connector holder  132  for reasons mentioned below. 
     The connector holder  132  and fiber optic connector  10  are shown in isolation in  FIG. 7 . In the embodiment shown, the connector holder  132  includes a holding portion  150  extending from the base portion  134 . The holding portion  150  defines a receptacle for receiving at least a portion of the connector housing  19 . Although the holding portion  150  is shown as completely surrounding a portion of the connector housing  19 , the holding portion  150  may alternatively define a U-shaped or otherwise open receptacle between first and second walls  152 ,  154  that define opposite sides of the holding portion  150 . Any design that allows the connector holder  132  to be securely mounted onto the fiber optic connector  10  (or, stated differently, that allows the fiber optic connector  10  to be securely mounted onto the connector holder  132 ) will suffice. The secure mounting may be achieved by snap-fit between a portion of the connector holder  132  and a portion of the fiber optic connector  10  (e.g., a latch arm  156  extending from the connector housing  19 ), an interference fit, complementary locking elements engaging each other, or the like. 
     Advantageously, and as shown in  FIG. 7 , the holding portion  150  of the connector holder  132  may have a width less than a width of the base portion  134 . Such an arrangement provides the connector holder  132  with a pedestal-like configuration that may be easier for a user to grip and manipulate when loading the connector holder  132  and fiber optic connector  10  into the installation tool  130 . In particular, aligning the base portion  134  of the connector holder  132  with the connector receiving area  138  to allow the base portion  134  to be received therein may be facilitated by such a configuration. The first and second walls  152 ,  154  being curved inwardly toward each other may also improve ergonomics by making the connector holder  132  easier to grip (e.g., between a user&#39;s thumb and finger). However, in other embodiments the first and second walls  152 ,  154  may not be curved or may be provided with a different configuration than what is shown in  FIG. 7 . 
     Now referring to both  FIGS. 6 and 7 , it can be seen how in this embodiment the base portion  134  of the connector holder  132  and the connector holding area  138  of the installation tool  130  are shaped so that the connector holding area  138  only receives and cooperates with the base portion  134  when the connector holder  132  is in a desired orientation with respect to the installation tool  130 . Stated differently, unless the connector holder  132  (and, therefore, the fiber optic connector  10  mounted to the connector holder  132 ) is oriented a desired way, the connector holding area  138  will not receive and cooperate with the base portion  134  to securely position the fiber optic connector  10 . There is only one desired orientation in the embodiment shown; one where the rear end of the fiber optic connector  10  extends into the actuation assembly  140  and the front end faces the VFL assembly  46 . Thus, unless the connector holder  132  is oriented in this particular way, the connector holding area  138  will not receive and cooperate with the base portion  134 . Providing the base portion  134  with a shape that results in the bottom surface  136  of the connector holder  132  having a rotationally asymmetric profile, such as a trapezoid (as shown), and the connector holding area  138  with a complementary shape/profile, is one possible way of limiting the cooperation to a single orientation. The shapes and relationship, in effect, make the loading process for the fiber optic connector  10  more intuitive and increases the likelihood of proper positioning for the termination process. Additional advantages may be obtained by providing the connector holder  132  and connector holding area  138  with the same or similar coloring or indicia, thereby making the loading process even more intuitive. 
       FIGS. 8-10  illustrate how different connector holder designs may be provided for different designs of fiber optic connectors. Connector holders  132 ,  132 A, and  132 B are shown for LC, ST, and SC-type fiber optic connectors  10 ,  10 A, and  10 B, respectively, as examples of this feature. In a manner not shown herein, connector holders may have designs for accommodating other types of fiber optic connectors. Advantageously, however, the base portion  134  of each connector holder design is similar. The similarity allows the different connector holder designs (and, therefore, different fiber optic connector designs) to be received in and cooperate with the same connector holding area  138  on the body  32  of the installation tool  130 . 
     The general principles described above with respect to the connector holder  132  may be applicable to a wide variety of systems for terminating one or more optical fibers. For example,  FIG. 11  illustrates a portion of an alternative embodiment of an installation tool  230  incorporating the features described above. The installation tool  230  is based upon the same or similar principles as the installation tools  30  ( FIGS. 2-4 ) and  130  ( FIG. 6 ), but has a different shape/configuration of components. Most notably, the installation tool  230  includes a movable adapter  232  to accommodate different fiber optic connector designs, as opposed to separate adapters  54  ( FIGS. 3-5B ). The adapter  232  is part of a test system  234  that serves the same purpose as the VFL assembly  46  in the installation tools  30  and  130 , namely checking the splice connection that the installation tool  230  eventually establishes between a fiber optic connector and field optical fiber. A brief description of the test system  234  and how the connector holder  132  may be used to facilitate interfacing with the adapter  232  (in addition to positioning the fiber optic connector  10  relative to the actuating assembly  140 ) will be provided below. However, these and other aspects of the installation tool  230  are more fully described in U.S. Provisional Patent Application No. 61/871,396 (“the &#39;396 application”), filed on Aug. 29, 2013, and U.S. patent application Ser. No. 14/070,876 (“the &#39;876 application”), filed on Nov. 4, 2013, both of which are entitled “TEST SYSTEM FOR CHECKING A SPLICE CONNECTION BETWEEN A FIBER OPTIC CONNECTOR AND ONE OR MORE OPTICAL FIBERS”, and both of which are herein incorporated by reference in their entirety. 
     In general, the adapter  232  includes different connector receiving areas for interfacing with different designs of connector holders  132  and fiber optic connectors  10 , such as those shown in  FIGS. 8-10 . First and second connector receiving areas  240 ,  242  are provided in the embodiment shown and at least partially defined by distinctly shaped connector receptacles on a front side of the adapter  232 . The first connector receiving area  240  may be configured to interface with one or more designs of fiber optic connectors having a 1.25 mm diameter ferrule, such as LC-type fiber optic connectors, while the second fiber optic connector  242  may be configured to interface with one or more designs of fiber optic connectors having a 2.5 mm diameter ferrule, such as SC and ST-type fiber optic connectors. As described in the &#39;396 and &#39;876 applications, different embodiments may have different numbers of connector receiving areas to accommodate these same types/designs of connectors in a different manner (e.g., dedicated connector receiving areas for SC, ST, and LC-type fiber optic connectors) and/or to accommodate other types of fiber optic connectors. 
     Although not shown in  FIG. 11 , one or more optical power generators and one or more jumpers are provided as part of the test system  234 , with the latter being coupled to a back end (not shown in  FIG. 11 ) of the adapter  232  so that light energy can be delivered to the connector receiving areas  240 . To this end, the optical power generator(s) and jumper(s) function in a manner similar to those part of the VFL assembly  46  ( FIGS. 3 and 4 ). To allow the delivery of the light energy through the adapter  232 , first and second jumpers (not shown) or other waveguides may extend from the back end of the adapter  232  to the first and second connector receiving areas  240 ,  242 . Using the first and second jumpers is believed to help strip extraneous modes out of the light being launched into the fiber optic connector, particularly if the first and second jumpers are mandrel-wrapped within the adapter  232 . 
     A general sequence of steps in using the installation tool  230  may involve first making sure that the adapter  232  is spaced from the connector holding area  138  ( FIG. 11 ). This may be done by pressing a button (not shown) or other actuator operably coupled to a cradle  250  to which the adapter  232  is mounted in some embodiments, and in other embodiments by manually moving the adapter  232  and cradle  250  along guide rails  252  away from the connector holding area  138 . The fiber optic connector  10  is then loaded into the installation tool  230  by positioning the connector holder  132  in the connector holding area  138 , as shown in  FIG. 12 . Before or after this step, it may be necessary to rotate the adapter  232  about a pivotal connection  254  to align the appropriate connector receiving area  240 ,  242  with the fiber optic connector  10 . The adapter  232  is then moved toward the fiber optic connector  10  to bring the first or second connector receiving area  240  (or  242 , depending on the type of the fiber optic connector  10 ) into proximity of and/or engagement with the fiber optic connector  10 .  FIG. 13  illustrates the installation tool  230  after this step when an LC-type fiber optic connector  10  has been loaded into the installation tool  230 . As can be appreciated, the cooperation between the base portion  134  of the connector holder  132  and the connector holding area  138  retains the fiber optic connector  10  in position. This helps ensure accurate and repeatable interfacing with the connector receiving areas  240 ,  242  on the adapter  232 , thereby increasing the likelihood of the test system  234  operating as intended so that users can take benefit from the advantages associated with the test system  234  (namely the movable adapter  232  to accommodate different fiber optic connector designs/types). 
     To this end, the connector holder  132  may be beneficial to use in connection other test systems that involve a movable adapter. The test systems may be integrated into an installation tool like the test system  234  such that the connector holder  132  securely positions a fiber optic connector relative to both an actuation assembly of the installation tool and the adapter of the test system. Alternatively, the test systems may be stand-alone systems. The adapter in such other integrated or non-integrated test systems may have a different form factor and may move in a different manner than the adapter  232 .  FIGS. 14A-14D  illustrate a portion of a test system  400  as an example of these variations. 
     In the test system  400 , the adapter  232  is shown as a block including first and second receptacles  402 ,  404  on a front side  406 . The first and second receptacles  402 ,  404  have distinct shapes and at least partially define the first and second connector receiving areas  240 ,  242 . The adapter  232  may also include first and second channels or guides  408 ,  410  extending from the front side  406  of the block to further define the first and second connector receiving areas  240 ,  242 . 
     An optical power delivery system for the test system  400  is not shown in  FIGS. 14A-14D  to simplify matters. However, first and second mating structures  414 ,  416  can be seen on a rear side  418  of the adapter  232  opposite the first and second connector receiving areas  240 ,  242 . The first and second mating structures  414 ,  416  are configured to receive and align the ends of jumpers that are coupled to one or more optical power generators (similar to the VFL assembly  46 ). Like the embodiment of FIGS.  11  and  12 A- 12 C, the first connector receiving area  240  is configured to interface with LC-type fiber optic connectors. For example, the first receptacle  402  and/or first channel  408  may be shaped to only receive, engage, or otherwise mate with the connector holder  132  ( FIGS. 6-8 ). The block of the adapter  232  may include a locking element  424  configured to cooperate with a complementary locking element (not shown) on the connector holder  132  to allow the components to be secured together. The locking element  424  may be in the form of a ball plunger, a spring plunger, latch, detent, magnet, or any other structure that is able to cooperate with the complementary locking element (e.g., a hole, pocket, flange, latch, magnet, etc.) to securely position the connector holder  132  relative to the adapter  232 . 
       FIG. 14A  illustrates the adapter  232  in a first position with the first connector receiving area  240  aligned with a fiber optic connector  10 , which is a LC-type fiber optic connector, and  FIG. 14B  illustrates the fiber optic connector  10  and connector holder  132  moved to engage and interface with the first connector receiving area  240 . When in this position, the ferrule  12  of the fiber optic connector  10  is aligned with and optically coupled to a jumper of the optical power delivery system. The splice connection between the stub optical fiber  14  and field optical fiber  15  within the fiber optic connector  10  may then be checked in a manner similar to that discussed above for the VFL assembly  46  of the installation tool  30 . 
     In the embodiment shown, the second connector receiving area  242  is configured to interface with SC and ST-type fiber optic connectors. Thus, if the fiber optic connector whose splice connection is being tested is either an SC or SC-type fiber optic connector rather than a LC-type fiber optic connector, the adapter  232  is moved relative to a body  412  to a second position shown in  FIG. 14C  to align the second connector receiving area  242  with the fiber optic connector  10 . The movement of the adapter  232  is translational (e.g., sliding movement) rather than rotational in this embodiment. 
     The manner in which the second connector receiving area  242  is configured to interface with the fiber optic connector  10  may be similar to that discussed above with respect to the first connector receiving area  240 . That is, the second receptacle  404  and/or second channel  410  may be shaped to only receive, engage, or otherwise mate with a connector holder  132  associated with SC or ST-type fiber optic connectors.  FIG. 14D  illustrates the fiber optic connector  10  and connector holder  132 A moved to engage and interface with the second connector receiving area  242 . When in this position, the ferrule  12  of the fiber optic connector  10 A is aligned with and optically coupled to a jumper of the optical power delivery system. The splice connection between the stub optical fiber  14  and field optical fiber  15  within the fiber optic connector  10 A may then be checked in the manner described above. 
     Note that the first and second connector receiving areas  240 ,  242  may be labeled and/or color coded to match labels and/or colors of the connector holders  132 . Such labeling and/or color coding makes it easier for a user to know whether to move the adapter  232  to the first or second position. 
     It will be apparent to those skilled in the art that further embodiments, modifications, and variations can be made without departing from the scope of the claims below. Since modifications, combinations, sub-combinations, and variations of the disclosed embodiments may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and their equivalents. 
     Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular order be inferred.