Patent Publication Number: US-2019174206-A1

Title: Light launch device with improved usability and performance

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority of U.S. Provisional Application Ser. No. 62/594,843, filed Dec. 5, 2017, the content of which is relied upon and incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The disclosure relates to a light launch device with improved usability and performance. In particular, the disclosure relates to a light launch device with at least some internally housed cable, at least one optical connector, a removable faceplate, alternating laser emission, and/or optimized cycle emission range. 
     Computer networks continue to increase in size and complexity. Businesses and individuals rely on these networks to store, transmit, and receive critical data at high speeds. Even with the expansion of wireless technology, wired connections remain critical to the operation of computer networks, including enterprise data centers. Portions of these wired computer networks are regularly subject to removal, replacement, upgrade, or other moves and changes. To ensure the continued proper operation of each network, the maze of cables connecting the individual components must be precisely understood and properly connected between specific ports. 
     In many cases, a network&#39;s cables, often called patch cords, can be required to bridge several meters across a data center, among other uses (e.g., within high performance computers, in outside-plant cabinets, etc.). These cables are often used between racks of servers, switches, and patch panels. The cables may begin in one equipment rack, run through the floor or other conduit, and terminate at a component in a second equipment rack. Data center operators may need to reconfigure patch panel endpoints to adapt to changes in use patterns or to turnover in equipment, which requires knowing the attachment location of both ends of the cable. To change the configuration of a patch cord, an operator needs to know where both ends of the cord are attached. However, in practice, it is not unusual for the operators to only know where one end of the patch cord is connected. Determining the location of the other end of a particular cable can be time consuming and fraught with risk. For example, disconnecting the wrong cable can interrupt important or critical network traffic. 
       FIGS. 1A-1B  are views of network cables (e.g., patch cords  100 ) used in fiber optic equipment. More specifically,  FIG. 1A  is a perspective view of an equipment rack  102  supporting patch cords  100 , and  FIG. 1B  is a perspective view of an under-floor cable tray  104  supporting patch cords  100 .  FIGS. 1A-1B  illustrate a problem that occurs in data centers or similar network locations, which is congestion and clutter caused by large quantities of patch cords  100 . Network operators frequently need to change connections to accommodate moves, additions, and changes in the network. However, operators may find it difficult to trace a particular patch cord  100  from the source to the receiver (e.g., ends of the patch cords  100 ) when the network location is congested, as illustrated in  FIGS. 1A and 1B . 
     As a result, there is a need for a traceable cable and/or light launch device that allows a network operator to quickly identify the terminal end of a given cable (e.g., such as those that are being replaced, relocated, or tested) with a low possible risk of error. 
     No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinency of any cited documents. 
     SUMMARY 
     Disclosed herein is a light launch device that may be used with a traceable patchcord to help identify the ends of the patchcord. The light launch device has improved usability and performance. In particular, the light launch device includes a launch cable and emission connector, a removable faceplate, alternating laser emission, and/or optimized pulse emission. The internally housed launch cable and emission connector facilitate portability and ease of use by consolidating the various components of the light launch device. The removable faceplate is positioned over the bulkhead connected to the input connector of a launch cable assembly to prevent access to the connection during normal use but selectively allowing access for maintenance or launch cable assembly replacement. The alternating laser emissions and/or optimized pulse emissions decrease power consumption while maintaining, or in some cases improving, cable tracing effectiveness. 
     One embodiment of the disclosure relates to a light launch device for a traceable fiber optic cable assembly. The light launch device includes a housing, at least one light source, and a launch cable assembly. The housing includes a body and a cover. The body and the cover define an interior of the housing therebetween. The light source is configured for generating an optical tracing signal. The launch cable assembly includes an emission connector and a launch cable. The emission connector is positionable within the interior of the housing. The launch cable includes a first launch optical fiber. The first launch optical fiber includes a first input end and a first emission end. The first emission end is in the emission connector and the first input end is in optical communication with the light source to receive the optical tracing signal therefrom. The launch cable is positionable within the interior of the housing. 
     An additional embodiment of the disclosure relates to a light launch device for a traceable fiber optic cable assembly. The light launch device includes a housing, at least one light source, and a launch cable assembly. The housing includes a body with a bulkhead and a faceplate removably attached to the body and covering the bulkhead when attached to the body. The at least one light source for generating an optical tracing signal is within the body and in communication with an optical connector receptacle on the bulkhead. The launch cable assembly includes a launch cable, an input connector at a first end of the launch cable, and an emission connector at a second end of the launch cable. The input connector is coupled to the optical connector receptacle of the bulkhead and the emission connector is configured to selectively engage a fiber optic connector of a traceable fiber optic cable. 
     An additional embodiment of the disclosure relates to a light launch device for a traceable fiber optic cable assembly. The light launch device includes a housing, at least one light source, and a launch cable assembly. The at least one light source is positioned within the housing for generating a first optical tracing signal and a second optical tracing signal. The launch cable assembly includes an input connector, an emission connector, a first launch optical fiber, and a second launch optical fiber. The input connector is configured to receive the first and second optical tracing signals from the light source. The emission connector is configured to selectively engage a fiber optic connector of a traceable fiber optic cable. The first launch optical fiber includes a first input end and a first emission end. The first input end is in communication with the light source to receive the first optical tracing signal therefrom, and the first emission end is in the emission connector. The second launch optical fiber includes a second input end and a second emission end. The second input end is in communication with the light source to receive the second optical tracing signal therefrom, and the second emission end is in the emission connector. The light source is configured to alternate emission of the first optical tracing signal into the first launch optical fiber and emission of the second optical tracing signal into the second launch optical fiber. 
     An additional embodiment of the disclosure relates to a light launch device for a traceable fiber optic cable assembly. The light launch device includes a housing, at least one light source, and a launch cable assembly. The light source is located within the housing for generating an optical tracing signal. The launch cable assembly includes an input connector, an emission connector, and a first launch optical fiber. The input connector is configured to receive the first and second optical tracing signals from the light source. The emission connector is configured to selectively engage a fiber optic connector of a traceable fiber optic cable. The first launch optical fiber includes a first input end and a first emission end. The first input end is in communication with the light source to receive the first optical tracing signal therefrom, and the first emission end is in the emission connector. The light source is configured to pulse emission of the first optical tracing signal into the first launch optical fiber such that light is emitted between 25%-35% of the duration of each cycle. 
     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 embodiments as described herein, including the detailed description which follows, the claims, as well as the accompanying drawings. 
     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 understanding 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 embodiments, and together with the description serve to explain principles and operation of the various embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of an equipment rack supporting patch cords; 
         FIG. 1B  is a perspective view of an under-floor cable tray supporting patch cords; 
         FIG. 2A  is a perspective view of a light launch device with an emission connector of a launch cable assembly of the light launch device attached to a first fiber optic connector of a data cable assembly; 
         FIG. 2B  is a perspective view of the emission connector of the light launch device of  FIG. 2A ; 
         FIG. 3A  is a schematic diagram of another embodiment of an exemplary cable tracing system; 
         FIG. 3B  is another schematic diagram illustrating the cable tracing system of  FIG. 3A ; 
         FIG. 3C  is another schematic diagram illustrating the cable tracing system of  FIG. 3A ; 
         FIG. 4  is a more detailed schematic diagram of an exemplary cable tracing system; 
         FIG. 5A  is a top perspective view of an exemplary light launch device in a closed orientation; 
         FIG. 5B  is a bottom perspective view of the light launch device of  FIG. 5A  in a closed orientation; 
         FIG. 6A  is a top perspective view of the light launch device of  5 A- 5 B in an open orientation and with a faceplate attached; 
         FIG. 6B  is a perspective view of the light launch device of  FIG. 6A  with the faceplate removed; 
         FIG. 6C  is a perspective back view of the faceplate of the light launch device of  FIG. 6A ; 
         FIG. 7A  is a view of the light launch device of  FIGS. 5A-6C  with the hub plate removed; 
         FIG. 7B  is a perspective view of internal components of the light launch device of  FIG. 7A ; 
         FIG. 8A  is a perspective view of an exemplary mandrel structure of a light launch device; 
         FIG. 8B  is a view illustrating light emission intensity from an optical fiber without use of the mandrel structure of  FIG. 8A ; 
         FIG. 8C  is a view illustrating light emission intensity from an optical fiber using the mandrel structure of  FIG. 8A ; 
         FIG. 9A  is a perspective view illustrating assembly of a first spool of an exemplary embodiment of a spool stack for use in a light launch device; 
         FIG. 9B  is a perspective view illustrating assembly of a second spool of the spool stack of  FIG. 9A ; 
         FIG. 9C  is a perspective view illustrating assembly of the second spool of the spool stack of  FIG. 9A ; 
         FIG. 10A  is a perspective view illustrating assembly of a first spool of another exemplary embodiment of a spool stack for use in a light launch device; and 
         FIG. 10B  is a perspective view illustrating removal of a second spool of the spool stack of  FIG. 10A . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present preferred embodiments, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. 
     Terms such as “left,” “right,” “top,” “bottom,” “front,” “back,” “horizontal,” “parallel,” “perpendicular,” “vertical,” “lateral,” “coplanar,” and similar terms are used for convenience of describing the attached figures and are not intended to limit this description. For example, terms such as “left side” and “right side” are used with specific reference to the drawings as illustrated and the embodiments may be in other orientations in use. Further, as used herein, terms such as “horizontal,” “parallel,” “perpendicular,” “vertical,” etc., include slight variations that may be present in working examples. 
     As used herein, the terms “optical communication,” “in optical communication,” and the like mean, with respect to two or more elements, that the elements are arranged such that optical signals may be passively or actively transmittable therebetween via a medium, such as, but not limited to, an optical fiber, one or more ports, free space, index-matching material (e.g., structure or gel), reflective surfaces, connectors, or other light directing or transmitting means. 
     As used herein, the terms “fiber optic cables” and/or “optical fibers” include all types of single mode and multi-mode light waveguides, including one or more optical fibers that may be uncoated, coated, colored, buffered, ribbonized and/or have other organizing or protective structure in a cable or outside of a cable, such as one or more tubes, strength members, jackets or the like. 
     As used herein, the term “signal” refers to light transmitted between devices, and such light may be modulated with data or an unmodulated. Unmodulated light may include, for example, a continuous wave of light. 
     As used herein, the term “data fiber” refers to an optical fiber for propagating modulated light. 
     As used herein, the term “coupler” refer to a device that connects light between at least two points, and includes, by way of example, optical connectors, optical fibers, ports, free space, index-matching material (e.g., structure or gel), and reflective surfaces. A coupler need not permanently connect light between the points, and may be removable and reconnectable. 
     Disclosed herein is a light launch device which may be used to inject light into a traceable patchcord or other device. In particular, the light launch device includes a launch cable, an emission connector, a removable faceplate, alternating laser emission, and/or optimized pulse emission. The internally housed launch cable and emission connector facilitate portability and ease of use by consolidating the various components of the light launch device. The removable faceplate is positioned over the bulkhead connected to the input connector of a launch cable assembly to prevent access to the connection during normal use but selectively allowing access for maintenance or launch cable assembly replacement. The alternating laser emissions and/or optimized pulse emissions decrease power consumption while maintaining, or in some cases improving, cable tracing effectiveness. 
     The content of U.S. patent application Ser. No. 15/411,157, entitled “Traceable Fiber Optic Cable Assembly with Fiber Guide and Tracing Optical Fibers for Carrying Light Received from a Light Launch Device;” U.S. patent application Ser. No. 15/411,198, entitled “Traceable Fiber Optic Cable Assembly with Illumination Structure and Tracing Optical Fibers for Carrying Light Received from a Light Launch Device;” and U.S. patent application Ser. No. 15/411,235, entitled “Light Launch Device for Transmitting Light into a Traceable Fiber Optic Cable Assembly with Tracing Optical Fibers,” are incorporated herein by reference in their entirety. 
       FIG. 2A  illustrates an exemplary cable tracing system  200  that can be used to allow a user to identify an opposite end of a fiber optic cable assembly  202  (may also be referred to as a data cable assembly, traceable cable assembly, etc.). The process of identifying a length of cable, a portion of the length of a cable, or an end point of the cable may be referred to as “tracing” the cable. The cable tracing system  200  facilitates tracing of ends of a traceable fiber optic cable (e.g., fiber optic cable  206 ) using fiber optic tracing signals.  FIG. 2A  illustrates a light launch device  204  with an emission connector  216  of a launch cable assembly of the light launch device  204  attached to a first fiber optic connector  208 A of a data cable assembly. The cable tracing system  200  comprises a traceable fiber optic cable assembly  202  and a light launch device  204  that is attachable to and removable from the traceable fiber optic cable assembly  202 . The cable tracing system  200  allows a user to selectively attach the light launch device  204  to a part of the traceable fiber optic cable assembly  202  and use the light launch device  204  to inject one or more optical tracing signals (e.g., a fiber optic tracing signal, a first optical tracing signal, a second optical tracing signal, etc.) into the traceable fiber optic cable assembly  202 . This allows the user to trace the location of part or all of the traceable fiber optic cable assembly  202  based on the propagation of the optical tracing signals in the traceable fiber optic cable assembly  202 . 
     The traceable fiber optic cable assembly  202  includes a fiber optic cable  206 , a first fiber optic connector  208 A (may also be referred to as a traceable fiber optic cable first connector, traceable fiber optic cable assembly first connector, etc.) at a first end of the fiber optic cable  206 , and a second fiber optic connector  208 B (may also be referred to as a traceable fiber optic cable second connector, traceable fiber optic cable assembly second connector, etc.) at a second end of the fiber optic cable  206 . The first fiber optic connector  208 A and the second fiber optic connector  208 B are present on opposite ends (e.g., first end  210 A, and second end  210 B) of the fiber optic cable  206  to allow the traceable fiber optic cable assembly  202  to act as a patch cord between components of a network. In use, the fiber optic cable  206  may extend between two locations, such as two equipment racks in a data center, telecommunications room, or the like. In some embodiments, the fiber optic cable  206  may have a length between close to zero meters and about 30 meters. In many embodiments, the fiber optic cable  206  may have a length between about 1 meter and about 5 meters. In other embodiments, the fiber optic cable  206  may have a length of more than 30 meters. 
     The first and second fiber optic connectors  208 A,  208 B are merely exemplary and other types of connectors other than the ones illustrated may be used. Thus, although  FIGS. 2A-2B  (among other figures herein) illustrate the first and second fiber optic connectors  208 A,  208 B as LC duplex connectors (e.g., Uniboot LC duplex connectors), the features described below may be applicable to different connector configurations and different connector sub-assembly designs. This includes simplex configurations of LC connector sub-assemblies, and both simplex and duplex configurations of different (i.e., non-LC) connector sub-assembly designs. In certain embodiments, the first and second fiber optic connectors  208 A,  208 B could include ribbon fiber or multi-fiber connectors (e.g., MPO (multi-fibre push on) connectors, MTP connectors, etc.). In some embodiments, each end of the fiber optic cable  206  includes a different type of connector, and/or, in some embodiments, the fiber optic cable  206  includes a furcation so that one or both ends of the cable include multiple cable segments and/or multiple connectors. 
     In certain embodiments, the first and second fiber optic connectors  208 A,  208 B each comprise an illumination component  212  to direct (e.g., propagate) the light emitted from a tracing fiber of the fiber optic cable  206  so that the fiber optic connectors  208 A,  208 B are more easily visible, for example, to workers in a data center environment. For example, in some embodiments, the illumination component  212  of the second fiber optic connector  208 B illuminates after receiving a first fiber optic tracing signal from the first fiber optic connector  208 A. The illumination of the second fiber optic connector  208 B may communicate the location of the second fiber optic connector  208 B, and/or the second illumination component  212  of the first fiber optic connector  208 A, to a worker. In some embodiments, a first fiber optic tracing signal and a second fiber optic tracing signal are transmitted consecutively and/or not simultaneously (e.g., not concurrently). In this way, one or more tracing optical fibers within the fiber optic cable  206  can provide for traceability of the fiber optic cable  206  from one or both of the ends  210 A,  210 B of the fiber optic cable  206 . The cable tracing system  200  provides the ability to trace a fiber optic cable  206  without disconnecting the fiber optic cable  206  from corresponding receptacles or ports. 
     In one embodiment, the traceable fiber optic cable assembly  202  comprises an end point only (EPO) configuration. In an EPO configuration, a far end of the traceable fiber optic cable assembly  202  (e.g., second fiber optic connector  208 B or a portion thereof) illuminates when a near end of the traceable fiber optic cable assembly  202  (e.g., a first fiber optic connector  208 A) is activated (e.g., receives an optical tracing signal). However, in other embodiments, the traceable fiber optic cable assembly  202  comprises an along-the-length (ATL) configuration. In an ATL configuration, at least a portion of the fiber optic cable  206  is illuminated. In some ATL configurations, the first fiber optic connector  208 A (or a portion thereof) and/or the second fiber optic connector  208 B (or a portion thereof) may also be illuminated in addition to a portion of the fiber optic cable  206 . In certain embodiments, in an ATL configuration light is emitted continuously along a length of the fiber optic cable  206  or at multiple points long a length of the fiber optic cable  206 . While the description below is written with respect to an EPO configuration, the teachings are also applicable to an ATL configuration. 
     The light launch device  204  comprises a launch module  214  and a launch cable assembly  215  including an emission connector  216  and a launch cable  218  positioned between the launch module  214  and the emission connector  216 . The launch module  214  generates the fiber optic tracing signal for direction through the launch cable  218  to the emission connector  216 . 
     The emission connector  216  is selectively attachable to and removable from a traceable fiber optic cable assembly (e.g., the traceable fiber optic cable assembly  202 ). In the embodiment illustrated in  FIG. 2A , for example, the emission connector  216  is attached to the first fiber optic connector  208 A. In other embodiments, the emission connector  216  may be attachable to other portions of the fiber optic cable, such as the second fiber optic connector  208 B or some other portion of the fiber optic cable  206 . In  FIG. 2A , the launch cable  218  directs (e.g., propagates) the fiber optic tracing signal from the launch module  214 , through the emission connector  216 , and to the first fiber optic connector  208 A or the second fiber optic connector  208 B. In this way, one or more launch optical fibers within the launch cable  218  provide for injection of the fiber optic tracing signal into the fiber optic cable  206  for traceability of the fiber optic cable  206  from one or both the ends  210 A,  210 B (e.g., the first fiber optic connector  208 A or the second fiber optic connector  208 B) of the fiber optic cable  206 . 
       FIG. 2B  is a perspective view of the emission connector  216  of the light launch device  204  disengaged from the first fiber optic connector  208 A (e.g., disconnected position, detached position, etc.). The emission connector  216  is configured to engage the first fiber optic connector  208 A to direct the optical tracing signal emitted from the light launch device  204  through the emission connector  216  and to the fiber optic cable  206 . The emission connector  216  can be removed from the first fiber optic connector  208 A after tracing is completed. 
     In use, a technician selectively engages (e.g., connects, attaches, etc.) the emission connector  216  with the first fiber optic connector  208 A (or the second fiber optic connector  208 B) in order to start tracing the fiber optic cable. The emission connector  216  can be attached or removed even when the first fiber optic connector  208 A and/or second fiber optic connector  208 B is engaged with another fiber optic component (e.g., patch panel, first fiber optic component, second fiber optic component, etc.), or any other network component. In the example embodiment illustrated in  FIG. 2B , for example, the emission connector  216  vertically engages the first fiber optic connector  208 A to inject light into the connector  208 A without obstructing the ferrules or connection end of the connector  208 A so that the connector  208 A can remain connected with the fiber optic component while performing a tracing operation. The emission connector  216  and the first fiber optic connector  208 A (or second fiber optic connector  208 B) mechanically interact with one another to align their respective optical fibers to direct an optical tracing signal from the emission connector  216  to the first fiber optic connector  208 A (or second fiber optic connector  208 B). 
     Once engaged, the user operates the light launch device  204  to inject an optical tracing signal into the first fiber optic connector  208 A (or second fiber optic connector  208 B) to illuminate the opposite connector (e.g., the second fiber optic connector  208 B) through the fiber optic cable  206 . In this way, a user can quickly and easily locate the opposite end of the traceable fiber optic cable assembly  202  which streamlines and simplifies the process of tracing or otherwise identifying a fiber optic cable  206  in a congested environment. In an ATL configuration, the user operates the light launch device  204  to inject an optical tracing signal into the first fiber optic connector  208 A (or the second fiber optic connector  208 B) to illuminate all or part of the length of the fiber optic cable  206 . In a combination of EPO and ATL configurations, the user operates the light launch device  204  to inject an optical tracing signal into the first fiber optic connector  208 A (or the second fiber optic connector  208 B) to illuminate: (1) all or part of the length of the fiber optic cable  206  and (2) the opposite connector (e.g., the second fiber optic connector  208 B). As a result, the technician can reliably identify the fiber optic cable  206  in question from amongst many other cables. The cable tracing system  200  may have the advantage of being an optically-activated cable tracing system using only optical tracing elements associated with the fiber optic cable  206  rather than, for example, electrical tracing elements (although electrical or active tracing elements may still be provided in addition to the optical tracing elements, if desired). 
     Once the tracing operation is completed, a user can disengage the emission connector  216  from the first fiber optic connector  208 A (or the second fiber optic connector  208 B). 
       FIGS. 3A-3C  are schematic diagrams of another embodiment of an exemplary cable tracing system providing a general overview of how the cable tracing system  300  selectively sends signals to illuminate ends of a cable, thereby allowing a user to trace the ends of a cable. The cable tracing system  300  comprises a traceable cable assembly  302  and a light launch device  304  (as similarly described above with  FIGS. 2A-2B ). As shown, the traceable cable assembly  302  comprises a first connector  308 A and a second connector  308 B, and a fiber optic cable  306  therebetween. In some embodiments, the fiber optic cable  306  may be more appropriately referred to as a conduit, without having any data transmission elements. It should be noted that other environments could use this tracing concept, such as other fiber optic deployment applications, electrical interconnects, and potentially liquid or gas conduits, etc. For example, the fiber optic cable  306  may direct fluids such as air or liquid and may be appropriate for use in a medical setting such as IV lines or oxygen tubing. 
     Any suitable type of connector could be used with the cable tracing system  300 . The first connector  308 A and the second connector  308 B may vary widely depending on the nature of the cable and the components being connected. The specific type of connectors should match the port configuration of the network component and will vary based upon the quantity and type of signals being directed by the cable. The first connector  308 A may include a first illumination component  310 A, and the second connector  308 B may include a second illumination component  310 B (as similarly described above with  FIGS. 2A-2B  and described in more detail below). The fiber optic cable  306  may have a different design or configuration depending on the types of connectors used. 
     The traceable cable assembly  302  further comprises a data transmission element  312  (e.g., optical data fiber), as well as a first tracing element  314 A (e.g., first tracing optical fiber) and/or second tracing element  314 B (e.g., second tracing optical fiber) extending between the first connector  308 A and the second connector  308 B. The data transmission element  312  extends between the first connector  308 A and the second connector  308 B to carry transmission of one or more data signals (e.g., optical data signals) therebetween. Generally, the data transmission element  312  is a structure capable of carrying a data signal from one end of the fiber optic cable  306  (or any other type of cable) to the other. The data transmission element  312  may be configured to direct an electrical signal, for example, using a copper wire or other electrically conductive material. Alternatively, or in addition, the data transmission element  312  may be configured to direct an optical signal by conducting electromagnetic waves such as ultraviolet, infrared, or visible light to carry data from one location to another. The data transmission element  312  could comprise one or more data transmission elements, which may be of the same type or different types as compared to one another. 
     The first tracing element  314 A and the second tracing element  314 B may be used to allow for accurate identification of both ends of the traceable cable assembly  302 . In particular, the first tracing element  314 A comprises a first input end  316 A and a first emission end  318 A. The first input end  316 A is positioned within the first connector  308 A and the first emission end  318 A is positioned within or external to the second connector  308 B and is in communication with the second illumination component  310 B. The second tracing element  314 B comprises a second input end  316 B positioned within the second connector  308 B and a second emission end  318 B positioned within or external to the first connector  308 A and in communication with the first illumination component  310 A. It is noted that although two tracing elements are shown, in certain embodiments, only one tracing element may be used. In some embodiments, the operator can visually identify the first tracing element  314 A and/or the second tracing element  314 B with or without special equipment, such as an infrared (IR) camera. In some embodiments, discussed below, the first tracing element  314 A and the second tracing element  314 B are in the form of tracing optical fibers configured to direct and emit tracer light for visualization purposes. 
     As explained below, the light launch device  304  comprises a launch optical fiber  320  to insert one or more tracing signals into one or both of the first tracing element  314 A and the second tracing element  314 B. The first and second input ends  316 A,  316 B of the first and second tracing elements  314 A,  314 B may be flat cleaved, flat polished or otherwise prepared to efficiently receive the light from the light launch device  304  and may be positioned flush with the connector wall, slightly inside the first and second connectors  308 A,  308 B or slightly outside the first and second connectors  308 A,  308 B. Further, one or more illumination components are positioned at the tracing optical fiber emission ends  318 A,  318 B which provide optical directing and/or optical scattering features to illuminate the first and second connectors  308 A,  308 B to be easily found by operators. 
       FIG. 3B  is an exemplary schematic diagram illustrating the cable tracing system  300  of  FIG. 2A  in use to illuminate the illumination component  310 B of the second connector  308 B. As shown, the first connector  308 A is mechanically engaged with and in communication with a first network component  322 A, and the second connector  308 B is mechanically engaged with and in communication with a second network component  322 B. Additionally, the launch optical fiber  320  of the light launch device  304  is in communication with the first input end  316 A of the first tracing element  314 A. The light launch device  304  emits one or more optical tracing signals (e.g., first optical tracing signal, second optical tracing signal) through the first input end  316 A, through the first tracing element  314 A, and exits through the first emission end  318 A into the second illumination component  310 B thereby illuminating the second illumination component  310 B. In this way, a user can connect the light launch device  304  to the first connector  308 A to locate the second connector  308 B by illumination thereof. 
       FIG. 3C  is another exemplary schematic diagram illustrating the cable tracing system  300  of  FIG. 2A  in use to illuminate the illumination component  310 A of the first connector  308 A. Here, the first connector  308 A is not mechanically engaged or in communication with a network component, but the second connector  308 B is mechanically engaged and in communication with the second network component  322 B. In this configuration, the launch optical fiber  320  of the light launch device  304  is in communication with the second input end  316 B of the second tracing element  314 B. The light launch device  304  emits at least one tracing signal through the second input end  316 B through the second tracing element  314 B and exits through the second emission end  318 B in the first illumination component  310 A thereby illuminating the first illumination component  310 A. In this way, a user can connect the light launch device  304  to the second connector  308 B to locate the first connector  308 A by illumination thereof, regardless of whether the first connector  308 A and the second connector  308 B are connected to a first network component  322 A or a second network component  322 B (e.g., when the second connector  308 B is connected to a second network component  322 B, and the first connector  308 A is not connected to a first network component  322 A). As noted above, the launch device  304  is designed such that it can launch light into the first or second connectors  308 A,  308 B without the need to disconnect the first or second connectors  308 A,  308 B from respective first and second network components  322 A,  322 B. Also, as noted above, the light launch device  304  can be connected to the first or second connectors  308 A,  308 B to illuminate part or all of the fiber optic cable  306  in an ATL configuration. 
     Now that a general overview of the cable tracing system  300  has been provided, a more detailed discussion of the cable tracing system  200  will be discussed. 
     In this regard,  FIG. 4  is a more detailed schematic diagram illustrating an exemplary embodiment of the cable tracing system  200  of  FIGS. 2A-2B . As shown in  FIG. 4 , the fiber optic cable  206  may include a first data transmission fiber  400 A (e.g., first data optical fiber, first data transmission element) and a second data transmission fiber  400 B (e.g., second data optical fiber, first data transmission element). The first data transmission fiber  400 A comprises a first end  402 A and a second end  404 A, and the second data transmission fiber  400 B comprises a first end  402 B and a second end  404 B. The first data transmission fiber  400 A and the second data transmission fiber  400 B carry optical data signals from the first fiber optic connector  208 A to the second fiber optic connector  208 B, and/or vice versa. Any number of data transmission fibers could be used, such as depending on networking requirements, data transmission requirements, etc. 
     Further, the fiber optic cable  206  comprises a first tracing optical fiber  406 A and a second tracing optical fiber  406 B for direction of a fiber optic tracing signal therethrough, thereby facilitating a user in tracing the ends of the fiber optic cable  206 . As noted above, one example of tracing elements is tracing optical fibers  406 A,  406 B. In particular, the first tracing optical fiber  406 A extends along the length of the fiber optic cable  206 , and the second tracing optical fiber  406 B extends along the length of the fiber optic cable  206  in the opposite direction. The first tracing optical fiber  406 A comprises a first input end  408 A and a first emission end  410 A, and the second tracing optical fiber  406 B comprises a second input end  408 B and a second emission end  410 B. The first input end  408 A of the first tracing optical fiber  406 A and the second emission end  410 B of the second tracing optical fiber  406 B are positioned within the first fiber optic connector  208 A and are in optical communication with the light source  416 , and the first emission end  410 A of the first tracing optical fiber  406 A and the second input end  408 B of the second tracing optical fiber  406 B are positioned within the second fiber optic connector  208 B. 
     In some embodiments, each of the first and second input ends  408 A,  408 B comprise a bend (at or proximate thereto), and each of the first and second emission ends  410 A,  410 B are generally straight (at or proximate thereto). The bend of the first and second input ends  408 A,  408 B allow injection of an optical tracing signal into one or more sides of the first and/or second fiber optic connectors  208 A,  208 B. The straight first and second emission ends  410 A,  410 B allow emission of an optical tracing signal into a center of the first and/or second fiber optic connectors  208 A,  208 B, and in particular, into an illumination structure of the first and/or second fiber optic connectors  208 A,  208 B (described in more detail below). In some embodiments, the emission ends of the tracing optical fibers may also be bent. For example, in some embodiments, the emission ends include a bend of between 0 and 360 degrees. The first and second input ends  408 A,  408 B are configured to receive light from the light launch device  204  while the emission ends  410 A,  410 B are configured to emit light. The bends at or near the first and second input ends  408 A,  408 B may be about 90 degrees (or any other angle) to allow for convenient injection of light into the first and second tracing optical fibers  406 A,  406 B. 
     Note that in certain embodiments, the fiber optic cable  206  only uses one of the first tracing optical fiber  406 A and the second tracing optical fiber  406 B. 
     The fiber optic cable  206  further comprises a jacket  412  (e.g., hollow tube forming a conduit) substantially surrounding at least a portion of the first data transmission fiber  400 A, the second data transmission fiber  400 B, the first tracing optical fiber  406 A, and the second tracing optical fiber  406 B for protection thereof. Alternatively, the first and second data transmission fibers  400 A,  400 B and/or the first and second tracing optical fibers  406 A,  406 B may be only partially embedded within the jacket  412  and/or mounted to an outer surface of the jacket  412 , or otherwise attached to the jacket  412 . The first data transmission fiber  400 A and/or the second data transmission fiber  400 B may have a core and/or cladding. Further, there may be strength members (e.g., aramid yarns) or other elements located within the fiber optic cable  206  between the first and second data transmission fibers  400 A,  400 B and the jacket  412 . 
     With continuing reference to  FIG. 4 , the light launch device  214  is used to inject an optical tracing signal into the first or second fiber optic connectors  208 A,  208 B or some other portion of the fiber optic cable  206  for transmission of the optical tracing signal to emit from an opposite end of the fiber optic cable  206  (in, in an ATL configuration, to emit from some or all of the length of the fiber optic cable  206 ) for a user to quickly and easily trace the fiber optic cable  206 . The light launch device  214  comprises a housing  414 , a launch cable  218 , and an emission connector  216 . In use, the emission connector  216  is attachable to a portion of the traceable cable (e.g., the first fiber optic connector  208 A, the second fiber optic connector  208 B). The housing  414  may house a number of elements to enable emission of light into the traceable cable  206 . In some embodiments, the housing  414  includes a light source  416  (e.g., laser source), an electrical power source  418  (e.g., one or more batteries), control circuitry  420  which may be respectively connected to other components within the housing  414  (e.g., to control the light source  416 ), a receiver  422  or other wireless communication components (e.g., to receive commands from an external controller), a speaker  424  (e.g., to allow for the generation of audible signals), a switch  426  (e.g., an on-off switch), and/or one or more user interface features. One or more of these elements could be included on and/or outside the housing  414  at another location of the light launch device  214 . For example, in some embodiments, the light source  416  (e.g., a red or green laser) is located at or near the emission connector  216  rather than in the housing  414 . 
     In certain embodiments, the housing  414  may be approximately the size of a standard flashlight or much smaller or larger depending on the application, and it is noted that the FIGURES referenced herein are not intended to be to scale. The housing  414  may be sufficiently durable to protect the components contained within the housing  414  (e.g., in the event of a drop onto a hard surface). 
     In one embodiment, the light source  416  may emit a wavelength that is chosen to enhance visibility, such as a wavelength as near to 555 nm as possible. In some embodiments, the light source  416  is a 520-540 nm green laser diode, LED (light emitting diode) or super-luminescent diode (SLD). Alternatively, other colors/wavelengths may be emitted, such as red light from approximately 620-650 nm. In other embodiments, non-laser light sources may be used, such as LEDs. Several factors may be considered when selecting an appropriate light source  416 , and the factors may include, but are not limited to, visibility, cost, eye safety, peak power, power consumption, size, and commercial availability. While the light source  416  is shown as part of the housing  414 , in other embodiments the light source  416  may be part of the emission connector  216  or may be located elsewhere on the light launch device  204 , such as on the launch cable  218 . In some embodiments, the power of the light source  416  is as high as can be used safely according to industry safety standards, such as a green laser up to 40 mW coupled to a multimode delivery waveguide fiber with core diameter of about 50 microns or more and a numerical aperture about 0.2 or more. 
     The launch cable  218  (e.g., delivery waveguide, umbilical, etc.) may comprise a first launch optical fiber  428 A (e.g., first launch optical fiber) and a second launch optical fiber  428 B (e.g., second launch optical fiber). At least a portion of the launch cable is positionable within the interior of the housing for storage and positionable external to the housing in use. In one embodiment, the first and second launch optical fibers  428 A,  428 B direct green, 520 nm semiconductor laser light and are a high numerical aperture, wide mode field, multimode fiber. In some embodiments, the first and second launch optical fibers  428 A,  428 B are 0.5 NA, 125 micron core delivery fibers that have a low index of refraction polymer cladding layer directly outside of the core glass. 
     In some embodiments, the light source  416  includes more than one light emitting features, such as the first light source  416 ( 1 ) and the second light source  416 ( 2 ) illustrated in  FIG. 4 . In certain embodiments, the first launch optical fiber  428 A is in optical communication with the first light source  416 ( 1 ) and the second launch optical fiber  428 B is in optical communication with the second light source  416 ( 2 ). 
     The first launch optical fiber  428 A comprises a first input end  430 A and a first emission end  432 A, and the second launch optical fiber  428 B comprises a second input end  430 B and a second emission end  432 B. The first and second input ends  430 A,  430 B are optically connected with the light source  416  (e.g., light source  416 ( 1 ) and light source  416 ( 2 )). In certain embodiments, the first input end  430 A is optically connected with the first light source  416 ( 1 ) and the second input end  430 B is optically connected with the second light source  416 ( 2 ). 
     The launch cable  218  may be several meters in length, for example, so that the housing  414  of the light launch device  204  can be placed on the ground or other convenient location while the emission connector  216  is coupled with the traceable fiber optic cable assembly  202  several meters away. The emission connector  216  may be mounted to, or otherwise provided at or near the first input end  408 A of the first tracing optical fiber  406 A or the second input end  408 B of the second tracing optical fiber  406 B. The emission connector  216  may help provide a high efficiency launch of light into the first tracing optical fiber  406 A and/or the second tracing optical fiber  406 B. 
     In use, the emission connector  216  may be attached to the first fiber optic connector  208 A, and the first emission end  432 A of the first launch optical fiber  428 A of the launch cable  218  is aligned with the first input end  408 A of the first tracing optical fiber  406 A. In this way, a first optical tracing signal that is generated by the light source  416 ( 1 ) is directed to the first launch optical fiber  428 A. The first optical tracing signal then exits the first emission end  432 A of the first launch optical fiber  428 A and enters the first input end  408 A of the first tracing optical fiber  406 A positioned in the first fiber optic connector  208 A. The first optical tracing signal then travels through the first tracing optical fiber  406 A until it exits the first emission end  410 A of the first tracing optical fiber  406 A positioned in the second fiber optic connector  208 B. Accordingly, a user can use the light launch device  204  to locate a second end  210 B of the fiber optic cable  206  after attaching the light launch device  204  to a first end  210 A of the fiber optic cable  206 . 
     The allowed mechanical tolerances for the first and second launch optical fibers  428 A,  428 B to the first and second tracing optical fibers  406 A,  406 B (e.g., tracing fiber) may be less than about +/−100 microns, and preferably less than about +/−50 microns, although broader tolerances are also useable in some embodiments. For example, the first and second launch optical fibers  428 A,  428 B and first and second the tracing optical fibers  406 A,  406 B could be selected to enable a larger tolerance. In some embodiments, the first and second launch optical fibers  428 A,  428 B have a narrower core diameter and mode field diameter (MFD) than the first and second tracing optical fibers  406 A,  406 B. In some embodiments, for example, the first and second tracing optical fibers  406 A,  406 B are a 240 micron diameter core 0.5 numerical aperture (NA) plastic optical fiber (POF). In such embodiments, there is 100% spatial overlap of the first and second launch optical fibers  428 A,  428 B to the first and second tracing optical fibers  406 A,  406 B for any lateral offset below 57.5 microns. In some embodiments, the NA of the first and second launch optical fibers  428 A,  428 B and the first and second tracing optical fibers  406 A,  406 B are the same so very little light is lost from typical angular misalignments of a few degrees. In some embodiments, launch optical fibers  428 A,  428 B are used with smaller MFDs than 125 microns and lower NAs if the tolerance stack up requires it (e.g., Corning VSDN fiber with an 80 micron MFD and a 0.29 NA). 
     In some embodiments, the light sources  430 A,  430 B both emit light during a tracing operation. Because both light sources  430 A,  430 B emit light, both the first and second launch optical fibers  428 A,  428 B receive and transmit light, and the emission connector  216  emits light from both the first emission end  432 A of the first launch optical fiber  428 A and the second emission end  432 B of the second launch optical fiber  428 A. As discussed in more detail below, the light sources  430 A,  430 B may emit light simultaneously or non-simultaneously. 
     As illustrated in  FIG. 4 , the fiber optic cable assembly  202  may be configured such that light from only one of the first launch optical fiber  428 A and the second launch optical fiber  428 A actually enters the first and second tracing optical fibers  406 A,  406 B. As discussed above, each fiber optic connector  208 A,  208 B of the traceable fiber optic cable assembly  202  includes an input end (e.g., input end  408 A) of one of the tracing optical fibers (e.g., first tracing optical fiber  406 A) and an emission end (e.g., emission end  410 B) of the other tracing optical fiber (e.g., second tracing optical fiber  406 B). As such, light from only one of the first and second launch optical fibers  428 A,  428 B of the launch cable  218  of the launch module  214  enters one of the tracing optical fibers (e.g., first or second tracing optical fibers  406 A,  406 B). However, by emitting light from both the first emission end  432 A of the first launch optical fiber  428 A and the second emission end  432 B of the second launch optical fiber  428 A, the emission connector  216  of the launch module  214  need not be keyed for only one connector (e.g., only the first connector  208 A or only the second connector  208 B) or specifically aligned with a connector in order to inject light therein. In other words, the emission connector  216  can be connected to either the first or second connectors  208 A,  208 B so that either the first emission end  432 A of the first launch optical fiber  428 A or the second emission end  432 B of the second launch optical fiber  428 A is aligned with an input end (e.g., input end  408 A or input end  408 B) of one of the tracing optical fibers. In addition, by emitting light from both the first emission end  432 A of the first launch optical fiber  428 A and the second emission end  432 B of the second launch optical fiber  428 A, the same connector can be used to inject light into both the first and second connectors  408 A,  408 B. This also enables support of either orientation of the emission connector  216  (e.g., reversible Uniboot connector) without requiring inspection or trial and error. 
     As discussed above, in certain embodiments, the light source  416  may include more than one light source (e.g., light sources  416 ( 1 ),  416 ( 2 )) or emit two tracing signals (e.g., by using an optical splitter or switch). In some embodiments, using two light sources (e.g., light sources  416 ( 1 ),  416 ( 2 )) may increase available optical power, such as to overcome a high optical loss budget and/or relax tolerances in other system components that may incur additional optical loss. In certain embodiments, the lasers have an output power above 50 mW (e.g., above ˜80 mW) and/or power dissipation in excess of 1.5 W. In certain embodiments, the two light sources  416 ( 1 ),  416 ( 2 ) emit green lasers, due to good visibility to the eye (e.g., green provides 4× visibility over red), as well as available laser power from compact laser diodes. However, other colors could be used. 
     In certain embodiments, to mitigate thermal issues (e.g., two simultaneously operated high power light sources  416 ( 1 ),  416 ( 2 )) and extend battery life (e.g., minimize power consumption), the two light sources  416 ( 1 ),  416 ( 2 ) are not illuminated simultaneously. For example, in some embodiments, the two light sources  416 ( 1 ),  416 ( 2 ) alternate emission. This may lower the peak current draw as well as lower heat dissipated by both light sources  416 ( 1 ),  416 ( 2 ). As noted above, in certain embodiments, only one laser light reaches the far end connector (e.g., fiber optic connector  208 A,  208 B), so that there is a pulsing effect (i.e., blinking light effect), which may effectively increase visibility as it is more noticeable to the eye. 
     In certain embodiments, for example, the first light source  416 ( 1 ) has a pulse duration of 50% of the cycle duration and the second light source  416 ( 2 ) has a pulse duration that is 50% of the cycle duration. Thus, for example, for a cycle duration of 10 seconds, each light source  416 ( 1 ),  416 ( 2 ) would have a pulse duration of 5 second. In other words, in some embodiments the first light source  416 ( 1 ) emits light during 50% of a cycle duration and the second light source  416 ( 2 ) emits light during the other 50% of the cycle duration. It is noted that, as used herein, each repeating cycle last for a certain period of time, called a cycle duration. The cycle duration is measured from the change of state of the first light source (e.g., light source  416 ( 1 )) from off to on, although the cycle could be measured from other events. Each cycle includes at least one light pulse having a pulse duration, which is the portion of the cycle duration during which the light source (e.g., light source  416 ( 1 ) or light source  416 ( 2 )) is on or emitting a tracing signal. 
     In some embodiments, the pulse duration of each light source (e.g., light sources  416 ( 1 ),  416 ( 2 )) is less than 50% of the cycle duration to further reduce power dissipation and heat production, resulting in higher available laser power and/or longer battery life. For example, in certain embodiments, each light source has a pulse duration that is less than about 300% of the cycle duration such that the lasers are engaged, and dissipate power and heat, only a total of about 60% of the cycle duration. 
     In some embodiments, as discussed above, the pulse duration of each laser occurs at different portions of the cycle duration. Thus, for example, in a cycle duration of 10 seconds where each laser has a pulse duration of 3 seconds, the cycle may appear as follows: the first light source  416 ( 1 ) engages for 3 second, neither light source is engaged for 2 seconds, the second light source  416 ( 2 ) engages for 3 seconds, and then neither light source is engaged for 2 seconds. Thus, there is a portion of each cycle duration wherein neither the first or the second light source  416 ( 1 ),  416 ( 2 ) is engaged. 
     In some embodiments, the first light source  416 ( 1 ) is configured to emit the first optical tracing signal in each instance of the repeating cycle and the second light source  416 ( 2 ) is configured to emit the second tracing optical signal in each instance of the repeating cycle. The first light source  416 ( 1 ) may emit the first optical tracing signal for about 25%-35% of the cycle duration and the second light source  416 ( 2 ) may emit the second optical tracing signal for about 25%-35% of the cycle duration. 
       FIGS. 5A-5B  are views of the light launch device  204  of  FIGS. 2A-2B  with a cover  504  (may also be referred to as a lid) in a closed orientation. As discussed above, the light launch device  204  may provide improved performance, operation, storage and/or usability. In certain embodiments, for example, the light launch device provides an all-optical method of tracing a cable (i.e., no electrical connections with or additions to fiber optic cable  206 ). The light launch device  204  eases operation due to simple winding and storage of the launch cable  218 , simple one screw cable replacement, and adjustable power (e.g., for Class 3R NAFTA (North American Free Trade Agreement), Class 2 EMEA (Europe, Middle East, and Africa), etc.). In certain embodiments, the light launch device  204  includes a high power in order to overcome a high loss budget and maintain visibility, an acceptable eye safety class despite the high power (e.g., Class 2, or Class 3R), and/or a two fiber output, such as to be compatible with a reversible LC connector on the end of the launch cable  218  (regardless of polarity). Referring to  FIG. 5A , the light launch device  204  includes a housing  500  including a body  502  and the cover  504  which is shown in the closed orientation. The body  502  and the cover  504  define an interior  506  therebetween. The light launch device  204  defines a front side  508 , back side  510 , left side  512 A, right side  512 B, bottom side  514 , and top side  516 . In certain embodiments, the cover  504  is made from hard plastic. The cover  504  provides protection without the need for a separate external case, which may be easily lost or not used, etc. 
     In certain embodiments, the light launch device  204  further includes a hanging strap  516  attached to the housing  500 , such as by being threaded through apertures  518  at the front side  508  of the cover  504  of the light launch device  204 . The hanging strap  516  may be used to hang the light launch device  204  (e.g., from a hook on the side of the equipment rack). Attaching the hanging strap  516  at the front side  508  of the cover  504  allows hanging of the light launch device  204  with the cover  504  in an open orientation (see  FIG. 2A ). 
     Referring to  FIG. 5B , the light launch device  204  includes a plurality of rubber feet  520  at the bottom  514  of the light launch device  204  to prevent movement of the light launch device  204  when placed on a surface (e.g., table). Further, the light launch device  204  includes a hand strap  522  at the bottom side  514  of the light launch device  204 . The hand strap  522  extends from the back  510  of the light launch device  204 , along at least a portion of the bottom surface of the body  502  of the housing  500  toward the front  508  of the light launch device  204 . Further, the hand strap  522  may be positioned about midway between the left side  512 A and the right side  512 B, such that the hand strap  522  may be comfortably placed in a user&#39;s left or right hand for one handed use. Further, the hand strap  522  may be recessed to allow laying the light launch device  204  flat on a table or other surface. Thus, the light launch device  204  provides flexible usage modes (e.g., hook, handheld, table/floor, open/closed, etc.). It is noted that whether placed on a surface or held in a hand, the cover  504  does not interfere with usage of the light launch device  204  (e.g., the cover may be open or closed). 
     In the embodiment illustrated in  FIG. 5B , the cover  504  of the light launch device  204  includes a passage  524 . In other embodiments, either the cover  504 , the body  502 , or the cover  504  and the body  502  may define the passage  524 . The passage  524  provides access to the interior  506  of the light launch device  204  and is configured to receive at least a portion of the launch cable  218  (see e.g.,  FIGS. 2A and 6A ) therein to allow for positioning the emission connector  216  (see e.g,  FIGS. 2A and 6A ) external to the housing  500  when the cover  504  is in the closed position. Thus, the emission connector  216  is positionable within the interior  506  of the housing  500  (e.g., for storage) or external to the housing  500  (e.g., when the emission connector  216  is in use). In this way, the launch cable  218  can extend from the interior  506  to the exterior of the housing  500  when the cover  504  is in the closed position. In other words, the cover  504  does not interfere with operation of the light launch device  204 , and operation of the light launch device  204  is possible with the cover  504  open or closed. Further, the light launch device  204  may still be hung, handheld, or placed on a table when the light launch device  204  is closed and in use. In other embodiments, the body  502  may define the passage  524  or the cover  504  and the body  502  may together define the passage  524 . 
     The light launch device  204  also includes a screw  526  inserted through a hole  528  at the bottom  514  of the light launch device  204  and extending though the body  502  to engage a faceplate  614  (see  FIGS. 6A-6C ) of the light launch device  204  to secure the faceplate  614  to the body  502 . 
       FIGS. 6A-6C  are views of the light launch device  204  of  FIGS. 2A-2B and 5A-5B  with the cover  504  in an open orientation. Referring to  FIG. 6A , the cover  504  of the light launch device  204  is hingedly connected to the body  502  of the housing  500  by a hinge  600  at a back side  510  of the light launch device  204 . Connecting the cover  504  to the body  502  prevents the cover  504  from being misplaced by a user, or from the unit being stored or transported without a protective lid. The cover  504  may be selectively pivoted between a closed position (as in  FIGS. 5A-5B ) and an open position (as in  FIGS. 6A-6B ). 
     Referring again to  FIG. 6A , in some embodiments the body  502  of the housing  500  includes a bottom housing body  604  and a top housing body  606 . Referring now to  FIG. 6B , the body  502  includes a hub  608  upwardly extending from an upper surface  610  of the body  502  and defining an outer perimeter  611 . The outer perimeter  611  is generally circular shaped and has a diameter D 1 . The upper surface  610  defines a storage slot  612  (e.g., rubber slot and/or other flexible material) positioned between hub  608  and the hinge  600  and extending between the left side  512 A and the right side  512 B. In certain embodiments, the storage slot  612  includes or consists of two rubber pads. The storage slot  612  provides an area for storing the emission connector  216  of the launch cable assembly  215 . 
     Referring to  FIGS. 6A and 6B , the body  502  of the housing  500  further defines a internal raceway  616  for storing a portion of the launch cable. In other words, at least a portion of the launch cable  218  is positionable in the internal raceway  616 , for example, by wrapping the portion of the launch cable  218  around the internal raceway  616 . A faceplate  614  is positioned within the interior  506  of the housing  500  when in use and has a diameter D 2  which is greater than the diameter D 1  of the hub  608 . Thus, in some embodiments, an outer perimeter  615  of the faceplate  614  extends past the outer perimeter  611  of the hub  608  to define the internal raceway  616  between the hub  608  of the body  502  and the faceplate  614 . At least a portion of the launch cable  218  of the launch cable assembly  215  is positioned within the internal raceway  616 . In particular, at least a portion of the launch cable  218  is wrapped around the outer perimeter  611  of the hub  608  and secured between the hub  608  and the faceplate  614  for storage. This allows for convenient storage and transportation of the launch cable  218  and emission connector  216 , which avoids wearing or breaking of the end connector (which may require replacement or return for repair by the manufacturer). 
     The emission connector  216  of the launch cable assembly  215  can be removably secured within the storage slot  612 . In other words, the storage slot  612  is configured to selectively retain the emission connector  216 . In particular, a length L 1  (also called a :slot length”) of the storage slot  612  is greater than a length L 2  (also called a “connector length”) of the emission connector  216 . In certain embodiments, the storage slot  612  has a length L 1  that is at least twice the length L 2  of the emission connector  216 . The emission connector  216  can be placed at any point along the length L 1  of the storage slot  612  to accommodate for variations in wrapping the launch cable  218  around the hub  608 . In certain embodiments, the storage slot  612  is of a different shape and the rubber sides of the storage slot  612  could incorporate flaps to further secure the emission connector  216  therein. The storage slot  612  is positioned within the housing  500  and outside the internal raceway  616 . The storage slot  612  enables a space to safely store the emission connector  216  while allowing for tolerance in cable length of the launch cable  218 , which affects the exact location of the emission connector  216 . 
     With continuing reference to  FIGS. 6A-6C , the faceplate  614  further defines a plurality of apertures  618  that provide access through the faceplate  614  to operational components on the hub  608  of the body  502 . The operational components include a power button  620  and light indicators  622 . In particular, the simple, single power button  620  eases operation. 
     In some embodiments, the body  502  also includes a bulkhead  626 . The light source  416  and the input end  430 A of the launch optical fiber (e.g., the launch optical fiber  704 A and/or the launch optical fiber  704 B) are in optical communication with each other via an optical connector receptacle  627  on the bulkhead  626 . The faceplate  614  is also positioned over a bulkhead  626  to protect the optical connector receptacle  627  of the bulkhead  626  and the mechanical engagement (e.g., optical couple) between the input connector  628  of the launch cable  218  and the internal components of the launch module  214  (see, e.g., description of  FIG. 4  including description of switch  426 , receiver  422 , light source  416 , electial power sourse  418 , etc.). In certain embodiments, the bulkhead  626  includes a shuttered connector receptacle (e.g., duplex shuttered LC connector receptacle) to allow a better eye safety rating as the concentrated laser light is blocked by the shutter if the operator inadvertently leaves the device on (or turns it on) while the launch cable  218  is disconnected. 
     The faceplate  614  discourages frequent disconnection of the launch cable  218  (which may cause premature wear of the optical connector receptacle  627  of the bulkhead  626 ), such that the user will only take the time and effort to remove the launch cable  218  when the launch cable  218  needs to be repaired or replaced (e.g., for maintenance). This prevents wearing out of the optical connector receptacle  627  of the bulkhead  626  from repeated connections without affecting the light launch device  204 . Further, the faceplate  614  improves the user experience as any light escaping from the optical connector receptacle  627  of the bulkhead  626  is blocked by the faceplace  614  when the faceplate is in place. 
     Referring to  FIG. 6B , the faceplate  614  is removable from the body  502 , thereby providing access to the optical connector receptacle  627  of the bulkhead  626  (may also be referred to as a bulkhead connector receptacle), such as for removal of the launch cable  218  when a replacement is needed. 
     The bulkhead  626  is positioned within the internal raceway  616 , or, in other words, the internal raceway  616  encircles the bulkhead  626 . The hub  608  includes the outer perimeter  611 , and a recessed perimeter  624  which extends inwardly from the outer perimeter  611 . The cable assembly  215  includes the input connector  628  (at an opposite end of the cable  218  as the emission connector  216 ) that is connectable or coupleable to the optical connector receptacle  627  of the bulkhead  626 . The at least one light source  416  (see  FIG. 4 ) is in communication with the optical connector receptacle  627  of the bulkhead  626 . 
     The hub  608  further includes a hub plate  630 , which is removable to allow selective access to body interior defined between the bottom housing body  604  and the top housing body  606 . 
     Referring to  FIG. 6C , the faceplate  614  of the light launch device  204  includes a screw attachment  632  extending at a back surface  634  of the faceplate  614 . In particular, the screw  526  extends through the hole  528  at the bottom  514  of the bottom housing body  604  through the body  502  through a hole  635  at an upper surface  610  of the top housing body  606  into the screw attachment  632  of the faceplate  614 . The screw attachment  632  is threaded and configured to engage the screw  526  to secure the faceplate  614  to the body  502  of the light launch device  204 . In this way, the head  636  of the screw  526  is accessible from the bottom  514  of the light launch device  204 . 
     The faceplate  614  further defines a wall  638  extending at least partially circumferentially around the perimeter  615  of the faceplate  614 . The wall  638  is at least slightly larger than the perimeter  611  of the hub  608 . The wall  638  further defines a gap  640  to receive at least a portion of the launch cable  218  therein to permit the cable to extend from the optical connector receptacle  627  of the bulkhead  626  to an exterior of the light launch device  204  while the faceplate  614  is attached to the hub  608 . 
       FIGS. 7A-7B  are views of the light launch device  204  of  FIGS. 2A-2B and 5A-6  illustrating a body interior  700  and interior connections and components. In particular,  FIG. 7A  is a perspective view of the light launch device  204  with the hub plate  630  (see  FIG. 6B ) removed.  FIG. 7B  is a perspective view of internal components of the light launch device  204 . The internal components include a first emission end  702 A of a first launch optical fiber  704 A and a second emission end  702 B of a second optical fiber  704 B. The internal components further include a spool  706  (or spool stack), with at least a portion of the first launch optical fiber  704 A and/or second optical fiber  704 B wrapped around the spool  706 . As fiber optics components such as Laser diodes and Photo diodes are usually provided with excess fiber, the excess fiber may be wrapped on a spool  706  (may also be referred to as a fiber management spool). 
     At least a portion of the first launch optical fiber  704 A and the second optical fiber  704 B is in communication with the laser package  708  (which may include, for example, the first light source  416 ( 1 ) and the second light source  416 ( 2 ) illustrated in  FIG. 4 ). Further, the laser package  708  is positioned adjacent or near a shared or common heatsink  712 . In particular, the heatsink  712  is mounted to the PCB  714  along with the laser package  708 . In certain embodiments, the heatsink  712  is significantly larger than the laser package  708  (e.g., to avoid the need for two large heatsinks, as well as simplify assembly of the tool). Internal components may further include a printed circuit board (PCB)  714  among other circuitry. 
     Referring to  FIGS. 2A, 4, and 5A-7B , the light launch device  204  for a traceable fiber optic cable assembly  202  includes a housing  500 , at least one light source  416 , and a launch cable assembly  215 . The housing  500  includes a body  502  and a cover  504  defining an interior  506  therebetween. The body  502  includes a bulkhead  626 . The housing  500  further includes a faceplate  614  removably attached to the body  502  and covering the bulkhead  626  when attached to the body  502 . The at least one light source  416  is configured for generating an optical tracing signal positioned within the interior  506  of the body  502  of the housing  500  and in communication with the optical connector receptacle  627  of the bulkhead  656 . The launch cable assembly  215  includes a launch cable  218  including a first launch optical fiber  704 A, with an input connector  628  at a first end of the launch cable  218 , and an emission connector  216  at a second end of the launch cable  218 . The input connector  628  is coupled to the optical connector receptacle  627  of the bulkhead  656 . The emission connector  216  is positionable within the interior  506  of the housing  500 . The emission connector  216  is configured to selectively engage a fiber optic connector  208 A,  208 B of a traceable fiber optic cable  202 . The first launch optical fiber  428 A includes a first input end  430 A and a first emission end  432 A. The first emission end  432 A is positioned in the emission connector  216  and the first input end  430 A is in optical communication with the light source  416  to receive the optical tracing signal therefrom. The launch cable  218  is positionable within the interior  506  of the housing  500 . 
     In certain embodiments, the light launch device  204  is configured to generate a first optical tracing signal and/or a second optical tracing signal and the launch cable assembly  215 . The launch cable assembly  215  includes an input connector  628  to receive the first optical tracing signal and the second optical tracing signal from the light source  416 , an emission connector  216  configured to selectively engage a traceable fiber optic cable assembly  202  (for example, the fiber optic connector  208 A of a traceable fiber optic cable  202 ), a first launch optical fiber  428 A, and a second launch optical fiber  428 B. The first launch optical fiber  428 A has a first input end  430 A and a first emission end  432 A. The first input end  430 A is in communication with the light source  416  to receive the first optical tracing signal therefrom, and the first emission end  432 A is positioned in the emission connector  216 . The second launch optical fiber  428 B has a second input end  430 B and a second emission end  432 B. The second input end  430 B is in communication with the light source  416  to receive the second optical tracing signal therefrom, and the second emission end  432 B is positioned in the emission connector  216 . In certain embodiments, the light source  416  is configured to alternate emission of the first optical tracing signal into the first launch optical fiber  428 A and emission of the second optical tracing signal into the second launch optical fiber  428 B. In certain embodiments, the first optical tracing signal comprises a green laser signal. In certain embodiments, the light source  416  emits the first optical tracing signal and the second tracing optical signal in each instance of a repeating cycle and each repeating cycle comprises a cycle duration. In certain embodiments, the light source  416  emits the first optical tracing signal for about 25%-35% of each cycle duration, and/or the light source  416  emits the second optical tracing signal for about 25%-35% of each cycle duration. In certain embodiments, the light launch device  204  includes a heatsink  712  positioned within the housing  500 . In certain embodiments, the at least one light source comprises a first laser source  416 ( 1 ) and a second laser source  416 ( 2 ) in thermal communication with the heatsink  712 , and the heatsink  712  is configured to dissipate heat generated by the first laser source  416 ( 1 ) and the second laser source  416 ( 2 ). 
       FIG. 8A  is a perspective view of the laser package  708  of the light launch device  204  of  FIGS. 2A-2B and 5A-7B . In certain embodiments, the maximum power of some lasers (e.g., 80 mW) may result in a beam emitted by the laser at or above a desirable level, such as a threshold eye safety classification (e.g., eye safety classification  3 B). To increase eye safety, the light launch device  204  expands the beam divergence emitted from the light launch device  204 . For example, in certain embodiments, a high NA (numerical aperture) fiber is used which has a more divergent beam. In certain embodiments, to cause the beam shape to fill more of the potential emitting cone, a form of mode homogenization is used. In certain embodiments, a light diffusing fiber may be used. In certain embodiments, a step index fiber wrapped in a figure eight around two mandrels may be used, as discussed below. The use of such fibers with a large core further increases the efficiency of the light coupling from the laser into the fiber, which in turn increases available loss budget. 
     In some embodiments, the laser package  708  further includes a laser housing  800  for the light source  416  (see  FIG. 4 ). In certain embodiments, the laser housing  800  is a duplex laser housing with a bracket  710  attached thereto. The bracket  710  includes a first pair of mandrels  802 A for the first launch optical fiber  704 A and a second pair of mandrels  802 B for the second optical fiber  704 B. The first pair of mandrels  802 A and the second pair of mandrels  802 B may decrease the optical intensity of the light within the first launch optical fiber  704 A and the second launch optical fiber  704 B. The first pair of mandrels  802 A includes a first mandrel  804 A (may also be referred to as column, etc.) and a second mandrel  804 B proximate the first mandrel  804 A. The first launch optical fiber  704 A is wrapped around the first mandrel  804 A and the second mandrel  804 B in a general figure eight pattern. Similarly, the second pair of mandrels  802 B includes a first mandrel  806 A (may also be referred to as column, etc.) and a second mandrel  806 B proximate the first mandrel  806 A. The second launch optical fiber  704 B is wrapped around the first mandrel  806 A and the second mandrel  806 B in a general figure eight pattern. In certain embodiments, two mandrels  804 A,  804 B are positioned within the housing  500  (e.g., the body  502 ) (see  FIGS. 5A-5B ), and the first launch optical fiber  704 A is wrapped in a figure eight configuration around the two mandrels  804 A,  804 B. 
     The figure eight pattern results in the first launch optical fiber  704 A and the second launch optical fiber  704 B switching between clockwise and counter-clockwise winding as it alternates between mandrels  804 A- 806 B. Bending the first launch optical fiber  704 A and the second launch optical fiber  704 B increases the incident angle of the light at the interface with the clad, where steeper angles transfer some of the light to higher modes. This results in the beam becoming more homogenous (i.e., the projected light becomes more even distributed). More windings and tighter windings increase the degree of homogenization. 
       FIG. 8B  is a view illustrating light emission intensity from an optical fiber without use of the laser package  708  of  FIG. 8A . In other words,  FIG. 8B  illustrates a beam output  810  from a step index pigtail without a mandrel wrap. Comparatively,  FIG. 8C  is a view illustrating light emission intensity from an optical fiber with use of the laser package  708  of  FIG. 8A . In other words,  FIG. 8C  illustrates a beam output  812  from a step index pigtail with a fiber mandrel wrapped five times in a figure eight format. Further, the use of such fibers with a large core further increases the efficiency of the light coupling from the laser into the fiber, which in turn increases available loss budget. In certain embodiments, Polymer Clad Silica fiber is used. 
     Referring again to  FIG. 2A , in certain embodiments the light launch device  204  includes a WiFi interface for remote control and monitoring. In particular, a WiFi (or any other wireless technology or protocol) module can be incorporated into the light launch device  204  which could be used for various functions, such as, for example, switching a laser on/off, adjusting power, adjusting blinking frequency, choosing laser output in an embodiment of a tool with multiple outputs feeding multiple cables, and/or any other additional controllable function the light launch device  240  might have. 
     In certain embodiments, the light launch device  204  includes a power control to adjust a laser power level, such as, for example, for battery consumption when lower power is sufficient, and/or to adjust visibility versus glare, etc. In certain cases, it may be desirable to adjust the power level. For example, for a short cable, or with low loss budget (e.g., in order to reduce glare or reflections at far end), and/or to conserve battery power where brightness not needed (e.g., in a darkened area). 
     In certain embodiments, the light launch device  204  includes an adjustable cycle duration or pulse duration. In certain applications, in a data center, for example, more than one technician may be using a light launch device  204 . In certain embodiments, the light launch device includes an adjustable blinking time period or frequency to allow for differentiating between light from two or more light launch devices  204 . 
     In certain embodiments, the light launch device  204  is configured to transmit an identification code sent over the tracing fiber. In a situation where multiple tools (or multiple outputs of a multi-output tool) are in use, it can be desirable for each light launch device  204  to have a unique identification code in order to confirm identification of the correct far end connector. 
     In certain embodiments, the light launch device  204  is configured to transmit a voice link over the tracing fiber. In certain embodiments, the light launch device  204  functions as a polarity check, for example, by emitting different colored light in each of the tracing fibers (e.g., blue on right and orange on left). In certain embodiments, the light launch device  204  includes two different colored lasers (i.e., instead of two identical green lasers). 
       FIGS. 9A-9C  are views illustrating spools to store extra length of fiber within the light launch device  204  of  FIGS. 2A-2B and 5A-7B . Referring to  FIG. 9A , a first spool  900 ( 1 ) includes a plurality of holes  902  with a device  904  applying screws (or other fasteners) through the holes  902  in the first spool  900 ( 1 ) to a surface inside the housing  500  (see  FIG. 5A ). Similarly, referring to  FIG. 9B , a second spool  900 ( 2 ) (with fiber  906  wrapped around the second spool  900 ( 2 )) is attached to the first spool  900 ( 1 ) by applying screws or other fasteners through the holes  902  in the second spool  900 ( 2 ) to attach the second spool  900 ( 2 ) to the first spool  900 ( 1 ). Referring to  FIG. 9C , a third spool  900 ( 3 ) is attached to the second spool  900 ( 2 ) by applying screws or other fasteners through the holes  902  in the third spool  900 ( 3 ) to attach the third spool  900 ( 3 ) to the second spool  900 ( 2 ). In this way, the plurality of spools  900 ( 1 )- 900 ( 3 ) form a spool stack  908 . In certain embodiments, when a new spool  900  is added, or a spool  900  (and/or associated fiber  906 ) needs to be replaced, the spools must be disassembled in the reverse order that they were assembled. For example, to replace the second spool  900 ( 2 ) would require disassembly of the third spool  900 ( 3 ) first. This may be a tedious process that might also damage the other components. 
       FIGS. 10A-10B  are views illustrating assembling and removing spools of another exemplary embodiment of a spool stack  1000  of the light launch device  204  of  FIGS. 2A-2B and 5A-7B . The spool stack  1000  provides for easy attachment and disassembly of the fiber management spools without a need to disassemble all of the spools when one of the optical components needs to be replaced. In particular, the device allows rolling each fiber onto a spool separately during the assembly and separate removal of each spool. In particular, the fixture saves installation and replacement time and reduces the likelihood for damage to the fiber or the optical components. 
     Referring to  FIG. 10A , a first spool  1002 ( 1 ) includes a plurality of circumferential wall segments  1006 , and two tabs  1008  extending outwardly from two of the circumferential wall segments  1006 . The tabs  1008  are at opposite ends of the first spool  1002 ( 1 ). The spool stack  1000  further includes a plurality of side supports  1004 A( 1 )- 1004 B( 2 ) (referred to generally as side supports  1004 ). 
     The first left side support  1004 A( 1 ) and the first right side support  1004 B( 1 ) are mounted to a surface of the light launch device  204  (not shown in  FIG. 10A ). Each side support  1004  includes a cavity  1010  defined in a side of the side support  1004  and configured to receive one of the tabs  1008 . Each side support  1004  further includes one or more posts  1012  extending from a top surface thereof, and one or more holes  1014  in a bottom surface thereof. The side supports  1004  are stackable. For example, the posts  1012  of the first left side support  1004 A(l) are inserted into the holes  1014  of the second left side support  1004 A( 2 ) when the left side support  1004 A( 2 ) is positioned on top of the first left side support  1004 A( 1 ). 
     For attaching the spool  1002 ( 1 ) to the enclosure, the fixture is slid between the two side supports  1004 A( 1 ),  1004 B( 1 ) until the tabs  1008  are snapped into the cavities  1010  of the side supports  1004 A( 1 ),  1004 B( 1 ), and is maintained therein by friction, such that a slight pulling on the spool  1002 ( 1 ) releases the spool  1002 ( 1 ) from the side supports  1004 A( 1 ),  1004 B( 1 ). The spool  1002 ( 1 ) removably engages a first left side supports  1004 A( 1 ) and a second side support  1004 B( 1 ). In particular, one tab  1008  of the first spool  1002 ( 1 ) engages the cavity  1010  of the first left side support  1004 A(l) and the other tab  1008  (not shown) engages the cavity  1010  of the second side support  1004 B( 1 ). 
     Referring to  FIG. 10B , the spool stack  1000  includes a plurality of spools  1002 ( 1 )- 1002 ( 3 ) and a plurality of side supports  1004 A( 1 )- 1004 A( 3 ). Because the spools  1002 ( 1 ) are mounted horizontally (not vertically) in the spool stack  1000 , they can also be detached horizontally. Adding an additional spool  1002  simply requires adding another pair of side supports  1004 B( 1 ),  1004 B( 3 ) onto the existing stacks of side supports  1004 . 
     Referring to  FIGS. 2A, 4, 5A-7B, and 10A-10C , in certain embodiments, a plurality of spools  1002 ( 1 )- 1002 ( 3 ) are mounted in the interior  506  of the housing  500 . At least one of the plurality of spools  1000 ( 1 )- 1000 ( 3 ) are configured to receive at least a portion of the first launch optical fiber  704 A. The plurality of spools  1000 ( 1 )- 1000 ( 3 ) includes a first spool  1000 ( 1 ) and a second spool  1000 ( 2 ) positioned within the body  502  and attached thereto. The first spool  1000 ( 1 ) is positioned between the body  502  of the housing  500  and the second spool  1000 ( 2 ), and the first spool  1000 ( 1 ) is configured to be detached from the housing  500  without detaching the second spool  1000 ( 2 ) from the housing  500 . 
     If, for example, the optical component attached to the second spool  1002 ( 2 ) needs to be replaced, the second spool  1002 ( 2 ) can be pushed out from the side supports  1004 A( 2 ),  1004 B( 2 ). When the new spool  1002  needs to be attached, it can easily be pressed to the middle location until its tabs  1008  are snapped into the cavities  1010  of the side supports  1004 A( 2 ),  1004 B( 2 ). 
     While the description above focuses on use of the light launch device  204  to injection signals into a traceable cable (e.g., traceable cable  206 ), the light launch device  204  can be used to inject signals (e.g., light) into other types of systems or apparatuses. For example, in some embodiments the light launch device  204  can be used to inject optical signals for the purpose of identifying faults in an optical connection as part of a visual fault locator (VFL). 
     It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the invention. 
     Many modifications and other embodiments of the embodiments set forth herein will come to mind to one skilled in the art to which the embodiments pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the description and claims are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. It is intended that the embodiments cover the modifications and variations of the embodiments provided they come within the scope of the appended claims and their equivalents. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.