An optical cassette includes a body defining a first termination region defined at the first end of the body; a second termination region defined at the second end of the body; a cable routing region disposed at a first level of the body; an optical splice holding region disposed at a second level of the body; and an optical coupler holding region disposed at the second level of the body. The first level is defined by a base of the body and the second level is defined by a divider tray that pivots relative to the body.

BACKGROUND

In optical fiber networks, optical signals are transmitted along optical fibers. To monitor the signal level or the conditions of the transmission, a small amount of light can be tapped from the main lines. For example, tapping can be achieved by inserting an optical coating film in the main optical path. The coating film will reflect a small amount of the light being transmitted in the main path, while leaving most of the light transmitted in the main path for communication purposes. This small amount of light that is reflected by the optical coating film is then collected and analyzed in order to monitor the signal level or the conditions of transmission of the optical communication line. Alternatively, optical couplers/splitters can be used to separate out optical signals to be monitored from the optical signals used for communication purposes. Optical couplers/splitters not only split off a portion of optical signals from a main line, but also can add optical signals to the main line.

Improvements are desired.

SUMMARY

An optical cable assembly optically couples at least one input line to at least one output line and to at least one monitoring line. The power of the optical signals received at the input line is split between the output line and the monitoring line.

In accordance with some aspects of the disclosure, an optical cassette has a first termination region at a first end, a second termination region at a second end, and cable management therebetween. In certain examples, the cable management is performed at two different levels (i.e., heights) within the optical cassette. For example, the cable management can be performed on a base of the cassette and on a tray overlaying the base.

In certain examples, the tray can pivot or otherwise move between a closed position and an open position. When closed, the tray blocks access to at least a portion of the first level of the cassette. When open, the tray allows access to the first level of the cassette.

In certain implementations, an optical splice holding region is disposed within the cassette. In certain examples, the optical splice holding region is disposed at the second level within the cassette.

In certain implementations, an optical coupler holding region is disposed within the cassette. In certain examples, the optical coupler holding region is disposed at the second level within the cassette.

In certain implementations, the adapters at the first termination region are different from the adapters at the second termination region. In certain examples, the adapters at the first termination region are single-fiber adapters. In certain examples, the adapters at the second termination region are multi-fiber adapters.

In some implementations, one or more pre-manufactured cable assemblies are installed within the cassette. In certain examples, two cable assemblies are installed within the cassette. In an example, the two cable assemblies are routed along opposite routing schemes. In other implementations, the fibers may be individually installed and routed within the cassette.

DETAILED DESCRIPTION

The present disclosure is directed to an optical cassette200having input lines, output lines, and monitoring lines. Within the optical cassette200, optical signals received over the input lines from an exterior of the optical cassette200are power split onto the output lines and at least some of the monitoring lines. In certain implementations, optical signals received over the output lines from an exterior of the optical cassette200are power split onto the input lines and others of the monitoring lines.

In some implementations, the input lines, output lines, and monitoring lines are formed from optical fibers that are separately routed within the optical cassette200. In other implementations, the input lines, output lines, and monitoring lines are formed by an optical cable assembly, such as either of optical cable assemblies100,150disclosed herein, that is assembled prior to being routed within the optical cassette200.

In certain implementations, the optical cassette200and/or the optical cable assembly100,150can be used for functions other than monitoring (e.g., redundancy). For example, the monitoring connector(s) can be used as redundant output and/or redundant input lines.

Optical Cable Assembly

An optical cable assembly100,150optically couples at least one input line to at least one output line and to at least one monitoring line. The power of the optical signals received at the input line is split between the output line and the monitoring line. In certain implementations, the optical cable assembly100,150optically couples a plurality of input lines to a corresponding number of output lines and a plurality of monitoring lines. For example, the optical cable assembly100,150may optically couple together one or more input connectors133,183, one or more output connectors136,186, and one or more monitoring connectors137,187,188.

The terms “input” and “output” are not intended to be limiting. Optical signals can travel in both directions between the input line and the output line.

In some implementations, the optical cable assembly150is unidirectional. In such implementations, a unidirectional optical cable assembly150includes the same number of monitoring lines as the number of input lines. The optical signals traveling from the input connector133,183to the output connector136,186are monitored. Example unidirectional optical cable assemblies150are shown inFIGS. 9-16. One example unidirectional cable assembly150is shown inFIGS. 9 and 16. Another example unidirectional cable assembly150is shown inFIGS. 10-15. The unidirectional cable assemblies differ in the routing of the optical fiber lines between the optical couplers110,160and an optical circuit120,170.

In other implementations, the optical cable assembly100is a bidirectional. In such implementations, the optical cable assembly100includes the monitoring lines corresponding to the input lines and additional monitoring lines corresponding to the output lines. The additional monitoring lines monitor optical signals traveling from the output connector136to the input connector133. Example bidirectional optical cable assemblies100are shown inFIGS. 1-8. One example cable assembly is shown inFIGS. 1 and 8and another example cable assembly is shown inFIGS. 2-7. The bidirectional cable assemblies differ in the routing of the optical fiber lines between the optical couplers110,160and an optical circuit120,170.

In certain implementations, the input lines, output lines, and monitoring lines (referred to herein as “optical lines”) are terminated at optical connectors. In some implementations, each optical line can be terminated by a single-fiber optical connector (e.g., an LC plug connector, an SC plug connector, an LX.5 plug connector, etc.). In other implementations, two or more optical lines can be terminated at a multi-fiber connector (e.g., an MPO connector, an HMFOC connector, etc.).

In the examples shown, the input lines are each terminated by single-fiber connectors133,173and the output lines are terminated by a single multi-fiber connector136,186. In a unidirectional cable assembly150, the monitoring lines are terminated by one multi-fiber connector137,187. In a bidirectional cable assembly100, the monitoring lines corresponding to the input lines are terminated by a first multi-fiber connector137,187and the monitoring lines corresponding to the output lines are terminated by a second multi-fiber connector138,188.

In other implementations, however, the input lines can be terminated by a single multi-fiber connector, the output lines can be separately terminated by single-fiber connectors, and/or the monitoring lines can be separately terminated by single-fiber connectors.

The optical cable assembly100,150includes an optical coupler110,160for each input line. Each optical coupler110,160has a coupler input112,162, a first coupler output114,164, and a second coupler output116,166. Each optical coupler110,160splits (e.g., power splits) optical signals carried over the coupler input112,162into split optical signals carried over the first and second coupler outputs114,164,116,166. The coupler input112,162is optically coupled to the input line, the first coupler output114,164is optically coupled to the output line, and the second coupler output116,164is optically coupled to the monitoring line.

In a bidirectional cable assembly100, each optical coupler110includes two input lines112a,112b. Each optical coupler110splits (e.g., power splits) optical signals carried over the first coupler input112ainto split optical signals carried over the first and second coupler outputs114,116. Each optical coupler110also power splits optical signals carried over the first output114into split optical signals carried over the first and second input lines112a,112b. The first input lines112aare optically coupled to the input lines for the cable assembly100. The second input lines112bare optically coupled to the additional monitoring lines of the cable assembly100.

In some examples, each optical coupler110,160power splits the optical signals in a 50/50 ratio. In other examples, each optical coupler110,160power splits the optical signals in an uneven ratio (e.g., 60/40, 70/30, 75/25, 80/20, 90/10, 95/5, etc.). Typically, in such examples, the smaller amount of power is directed to the corresponding monitoring lines. In other examples, different optical couplers110,160within a cable assembly100,150split the optical signals along different ratios. In In other implementations, each optical coupler splits the optical signals by wavelength instead of by power.

The optical cable assembly100,150can be efficiently assembled by manufacturing an optical circuit120,170including a plurality of optical fibers121,171extending between first ends122,172, and second ends123,173. The optical circuit120,170separates the unterminated ends122,123,172,173of the optical fibers121,171into groups. In some examples, each group of unterminated ends can then be efficiently optically coupled (e.g., fusion spliced) to input lines, output lines, monitoring lines, coupler input lines112,162, and/or coupler output lines114,116,164,166. In other examples, one or more of the groups may form the input lines, the output lines, and/or the monitoring lines.

The optical circuit120,170can be initially assembled by laying the optical fibers121,171over one or more substrates139,189. Adhesive or other bonding material holds the optical fibers121,171in position once laid on the substrate139,189. Assembling the optical circuit120,170on the substrate(s)139,189allows complex fiber routing (e.g., fiber cross-overs) to be completed easily and efficiently. In certain implementations, a conformal coating139a,189amay be laid over the optical fibers on one or more of the substrates139,189.

In certain implementations, the substrate139,189includes a flexible foil. In certain implementations, the substrate has an adhesive side and a non-adhesive side. The fibers are laid on the adhesive side. In certain implementations, the substrate139,189includes polyethylene terephthalate (PET). However, it should be understood that PET is simply one non-limiting example polymer that may be used to form the flexible foil of the present disclosure, and other polymers having similar characteristics and that are able to at least semi-rigidly support the fibers in a predetermined orientation are also usable in accordance with the inventive concepts of the present disclosure.

In the example shown inFIGS. 2 and 10, the optical circuit120,170is assembled over five substrates. The first ends122,172of the fibers121,171of the optical circuit120,170are disposed at a first substrate139,189and the second ends123,173of the fibers121,171are disposed at a second substrate139,189. In certain examples, a conformal coating139a,189ais laid over the fibers121,171to ribbonize the fibers121,171or otherwise hold the fibers in position even after the substrate139,189is removed.

An intermediate portion of the fibers121,171is laid over a third substrate139,189. Cross-overs or other complex routing of the optical fibers121,171is performed over this substrate139,189. Reference numbers120a,170arefer to the complex routing section of the fibers121,171. To enhance clarity, the complex routing is shown as a dashed box. The adhesive on the substrate139,189holds the fibers121,171in position. In certain examples, no further coating is layered over the fibers121,171. Accordingly, removing this substrate139,189from the fibers121,171results in loose fibers121,171. Leaving this section of the fibers121,171loose facilitates routing of the fibers within a cassette or other component.

In certain implementations, a portion of the fibers121,171to be cut is laid over a fourth substrate139,189. In certain examples, a conformal coating139a,189ais laid over the fibers121,171at the fourth substrate to ribbonize the fibers121,171or otherwise hold the fibers in position even after the substrate139,189is removed.

In certain implementations, the optical circuit120,170is tested prior to being terminated and/or spliced to optical couplers110,160or other optical components. For example, the first ends122,172of the optical fibers121,171may be coupled to testing equipment. In certain examples, the first substrate139,189is removed from the first ends122,172of the fibers121,171during testing. A conformal coating139a,189alaid over the fibers at the first substrate139,189holds the fibers in position during testing.

When the testing is complete, the optical fibers121,171may be cut (e.g., at the fourth substrate) to create new first ends122,172of the optical fibers121,171. These new first ends122,172may be optically coupled to the optical couplers110,160as will be described below after the fourth substrate139,189is removed. The conformal coating139a,189aat the fourth substrate may hold the new first ends122,172of the optical fibers121,171in their groups.

In other implementations, flexible optical circuits essentially comprise one or more fibers sandwiched between two flexible sheets of material, such as Mylar™ or another polymer. An epoxy may be included between the two sheets in order to adhere them together. Alternatively, depending on the sheet material and other factors, the two sheets may be heated above their melting point to heat-weld them together with the fibers embedded between the two sheets.

Additional details regarding the formation of the optical circuit can be found in U.S. Provisional Application No. 62/566,906, filed Oct. 2, 2017, titled “Fiber Optic Circuit and Preparation Method,” the disclosure of which is hereby incorporated herein by reference.

The optical circuit120,170separates the unterminated first ends122,172of the optical fibers121,171into at least a first group124,126,174and a second group125,127,175,177. Each group of first ends122,172is spaced from the other groups of first ends122,172, thereby enhancing the ease of identifying the ends. In certain examples, the adhesive or other bonding material holds the unterminated ends122,172in a row or other configuration to facilitate the optical coupling process (e.g., a mass fusion splice).

In some examples, such as the unidirectional optical cable assembly150shown inFIG. 9, the optical circuit170separates the unterminated first ends172into the first group174, the second group175, and another second group177. In other examples, such as the bidirectional optical cable assembly100shown inFIG. 1, the optical circuit120separates the unterminated first ends122into a first group124, a second group125, another first group126, and another second group127.

The optical circuit120,170also separates the unterminated second ends123,173of the optical fibers121,171into another plurality of groups including a third group128,178, a fourth group129,179, and a fifth group130,180. In certain examples, the optical circuit120may separate the unterminated second ends123of the optical fibers121into the third group128, the fourth group129, the fifth group130, and a sixth group131. Each group of second ends123,173is spaced from the other groups of second ends123,173, thereby enhancing the ease of identifying the ends. In certain examples, the adhesive or other bonding material holds the unterminated ends123,173in a row or other configuration to facilitate the optical coupling process (e.g., a mass fusion splice).

In some implementations, the first ends122,172of the optical fibers121,171are disposed at a first end101,151of the optical circuit120,170and the second ends123,173are disposed at a second end102,152of the optical circuit120,170. In certain implementations, the first end101,151faces in an opposite direction from the second end102,152. In some implementations, the number of fiber groups formed at the first end101,151matches the number of fiber groups formed at the second end102,152. It is noted that the group numbers provided herein are not intended to indicate placement on the optical circuit. For example, the third, fourth, and fifth groups need not be arranged in sequence. Rather, the third group may be disposed between the fourth and fifth group (e.g., seeFIG. 1).

The optical circuit120,170also includes the fiber routing between the groups124,125,126,127,174,175,177of first ends122,172and the groups128-131,178-181of second ends123,173. The fibers121,171in the optical circuit120,170do not merely extend in rows between the first and second ends. Rather, the optical circuit120,170includes any fiber crossovers and/or regroupings occurring between the first end101,151and the second end102,152of the optical circuit120,170. In certain examples, the fiber crossovers and/or regroupings occur over a predetermined length at an intermediate portion of the optical circuit120,170. In certain examples, the predetermined length extends over less than a majority of a length of the optical circuit120,170. In certain examples, the predetermined length extends over significantly less than a majority of a length of the optical circuit120,170.

The optical cable assembly100,150is further assembled by optically coupling (e.g., splicing) the optical couplers110,160to the optical circuit120,170. For example, the first group124,174of the unterminated first ends122,172is spliced to free ends113,163of at least some of the coupler input fibers112,162.

In the unidirectional cable assembly150ofFIGS. 9-16, a first group174of the unterminated first ends162are spliced (e.g., at an optical splice194) to the free ends163of all of the coupler input fibers162. In the bidirectional cable assembly100ofFIGS. 1-8, a first group124of the unterminated first ends122are spliced (e.g., at an optical splice144) to the free ends113of some of the coupler input fibers112,112a,112band another first group126of the unterminated first ends122are spliced (e.g., at an optical splice145) to the free ends113of others of the coupler input fibers112,112a,112b. In an example, the first group124is spliced to the coupler input fibers112,112a,112bof a first plurality of the couplers110and the other first group126is spliced to the coupler input fibers112,112a,112bof a second plurality of the couplers110.

The second group125,175of unterminated first ends122,172is spliced to free ends115,165of some of the coupler output fibers114,116,164,166. Another second group127,177of unterminated first ends122,172is spliced to free ends117,167of others of the coupler output fibers114,116,164,166. In an example, the second group125,175is spliced to the coupler output fibers114,116,164,166of a first plurality of the couplers110and the other second group127,177is spliced to the coupler output fibers114,116,164,166of a second plurality of the couplers110.

In certain implementations, the free ends113,163of the coupler input fibers112,112a,112b,162are ribbonized (e.g., bound into a row or matrix using adhesive) before being optically coupled to the first and optionally fourth groups124,174,126. The ribbonized section113r,163rof the free ends113,163can then be spliced (e.g., with a mass fusion splice) to the first groups124,174,126. In certain implementations, the free ends115,117,165,167of the coupler output fibers114,116,164,166are ribbonized before being optically coupled to the second groups125,127,175,177. The ribbonized section115r,165rof the free ends115,117,165,167can then be spliced (e.g., with a mass fusion splice) to the second groups125,127,175,177.

In other implementations, however, the optical circuit120,170includes only two groups of unterminated first ends122,172. A first of the groups can be spliced to all coupler input fibers112,162and a second of the groups can be spliced to all coupler output fibers114,116,164,166. In still other implementations, the optical circuit120,170can include more than four groups of unterminated first ends122,172that each can be spliced to the coupler input fibers112,162and/or coupler output fibers114,116,164,166.

The optical cable assembly100,150is further assembled by terminating the second ends123,173of the optical fibers121,171of the optical circuit120,170at optical connectors (e.g., plug connectors). In some implementations, the second ends123,173are directly terminated at the optical connectors. In other implementations, the second ends123,173are optically coupled (e.g., spliced) to stub fibers extending outwardly from the optical connectors.

In the examples shown, the third group128,178of the unterminated second ends123,173of the optical fibers121,171form or optically couple to the input lines for the cable assembly100,150; the fourth group129,179of the unterminated second ends123,173form or optically couple to the output lines; and the fifth group130,180of the unterminated second ends123,173form or optically couple to monitoring lines. In the unidirectional cable assembly150, the fifth group130,180forms or optically couples to all of the monitoring lines in the cable assembly150. In the bidirectional cable assembly100, the fifth group130,180forms or optically couples to the monitoring lines monitoring optical signals received at the input lines and a sixth group131forms or optically couples to the monitoring lines monitoring optical signals received at the output lines.

The second ends123,173of the optical fibers121,171of the third group128,178of the optical circuit120,170are terminated to one or more input plug connectors133,183. Accordingly, the one or more input plug connectors133,183are optically coupled to at least some of the coupler input fibers112,162. In the example shown, each second end123,173is separately terminated to a single-fiber plug connector133,183(e.g., an LC plug connector, an SC plug connector, etc.). In other examples, the second ends123,173may be terminated together at one or more multi-fiber connectors instead.

In some examples, each of the second ends123,173of the third group128,178may be directly terminated at a single-fiber plug connector133,173. In other examples, the second ends123,173of the third group128,178may be spliced (at an optical splice135,185) to a plurality of stub fibers134,184extending outwardly from the single-fiber plug connectors133,183. In an example, the stub fibers134,174may be ribbonized134r,174rprior to being spliced (e.g., mass fusion spliced) to the second ends123,173of the third group128,178.

The second ends123,173of the optical fibers121,171of the fourth group129,179of the optical circuit120,170are terminated to one or more output plug connectors136,186. Accordingly, the one or more output plug connectors136,186are optically coupled to the first coupler output fibers114,164. In the example shown, the second ends123,173of the fourth group129,179are inserted into a multi-fiber plug connector (e.g., an MPO plug connector, etc.)136,186. In other examples, the second ends123,173of the fourth group129,179may be separately terminated at corresponding single-fiber connectors instead.

The second ends123,173of the optical fibers121,171of the fifth group130,180of the optical circuit120,170are terminated to one or more monitoring plug connectors137,187. Accordingly, the one or more monitoring plug connectors137,187are optically coupled to the second coupler output fibers116,166. In the example shown, the second ends123,173of the fifth group130,180are inserted into a multi-fiber plug connector (e.g., an MPO plug connector, etc.)137,187. In other examples, the second ends123,173of the fifth group130,180may be separately terminated at corresponding single-fiber connectors instead.

In the bidirectional cable assembly100, the second ends123of the optical fibers121of the sixth group131of the optical circuit120are terminated to one or more additional monitoring plug connectors138. Accordingly, the one or more additional monitoring plug connectors138are optically coupled to the second coupler input fibers112bwhile the input connectors133,183are optically coupled to the first coupler input fibers112a. In the example shown, the second ends123of the sixth group131are inserted into a multi-fiber plug connector (e.g., an MPO plug connector, etc.)138. In other examples, the second ends123of the sixth group131,181may be separately terminated at corresponding single-fiber connectors instead.

It is noted that the optical fibers121,171of the fourth group129,179of the optical circuit120,170are optically coupled to the first coupler output fibers114,164, but not to the second coupler output fibers116,166. The optical fibers121,171of the fifth group130,180of the optical circuit120,170are optically coupled to the second coupler output fibers116,166, but not to the first coupler output fibers114,164. However, each of the second groups145,147,175,177of the optical circuit120,170are optically coupled to both the first and second coupler output fibers114,116,164,166.

As shown inFIGS. 8 and 16, the optical circuit120,170is assembled by laying at least sections of the fibers121,171across one or more substrates139,189. For example, a majority of the crossovers between the fibers121,171occurs on a main substrate139,189at an intermediate position along a length of the fibers121,171. In some examples, the main substrate139,189holds the entirety of the lengths of the optical fibers121,171. In other examples, portions of the fibers121,171are laid on separate substrates. For example, the first ends122,172of the fibers121,171may be grouped along a second substrate139,189and the second ends123,173of the fibers121,171may be grouped along a third substrate139,189.

The substrates139,189are removed from the optical fibers121,171before the optical cable assembly100,150is utilized (e.g., routed within a cassette). In some examples, the substrates139,189are removed after the splices135,144,145,146,147,185,194,195,197are formed. In other examples, the substrates139,189are removed before the splices135,144,145,146,147,185,194,195,197are formed. In some examples, the substrates139,189are removed after the second ends123,173of the fibers121,171are terminated at the plug connectors133,136,137,138,183,186,187. In other examples, the substrates139,189are removed before the second ends123,173of the fibers121,171are terminated at the plug connectors133,136,137,138,183,186,187.

In some implementations, the substrates139,189are removed by peeling the substrates139,189from the fibers121,171. In other implementations, the substrates139,189are removed by cutting the fibers121,171so that the substrates139,189are no longer connected to the optical circuit120,170. In certain implementations, the substrates139,189at the fiber ends122,123,172,173are removed by cutting while the main substrate139,189is removed by peeling.

In certain implementations, portions of the optical fibers121,171are ribbonized prior to removing the substrates139,189. For example, the first ends122,172of the fibers121,171in the first and second groups124,125,126,127,174,175,177may be ribbonized into the groups prior to cutting off the substrate139,189retaining the second ends123,173. Accordingly, the fiber ends122,172may be maintained in the respective groups124,125,126,127,174,175,177even after the substrates139,189are removed. The second ends123,173of the fibers121,171in the third, fourth, fifth, and sixth groups128,129,130,131,178,179,180may be ribbonized into the groups prior to cutting of the substrate139,189retaining the first ends122,172. Accordingly, the fiber ends123,173may be maintained in the respective groups128,129,130,131,178,179,180even after the substrates139,189are removed.

In certain implementations, indicators can be added to the fiber groups to identify each fiber group. Example indicators suitable for use with the optical circuit include a sleeve having tactile indicia, printed indicia, and/or color indicia to distinguish the indicator from the other indicators. In the example shown, each indicator includes tactile indicia in the form of bumps on an external surface of the sleeve. Each indicator disposed at a particular side of the optical circuit120,170has a unique number of bumps (e.g., 1, 2, 3, 4, etc.). In other examples, the indicators may be different colors or have different labeling printed thereon.

A first indicator can be disposed at the optical fibers121,171of the first group124,174; a second indicator can be disposed at the optical fibers121,171of the second group125,175; a third indicator can be disposed at the optical fibers121,171of the other second group127,177; and a fourth indicator can be disposed at the optical fibers121of the other first group126. In certain examples, indicators also can be disposed at the fibers121,171of the third, fourth, fifth, and sixth groups128-131,178-180.

In certain implementations, substrates are removed from the indicators prior to use of the cable assembly100,150. For example, the substrates of the indicators at the first and second groups124,126,174can be removed after being spliced to the appropriate optical coupler fibers. The substrates of the indicators at the third, fourth, fifth, and/or sixth groups128,178,129,179,130,180,131can be removed after the groups are terminated.

In some examples, the optical circuit120,170has a like number of groups at the first end101,151and the second end102,152. In such examples, the same indicator can be used at each end101,151,102,152. In the example shown inFIG. 4, four indicators140-143are used to designate the groups on each side of the circuit120. A first indicator140designates the first group124at the first end101and the fourth group129at the second end102; a second indicator141designates another of the first groups126at the first end101and the fifth group130at the second end102; a third indicator142designates one of the second groups125at the first end101and the sixth group131at the second end102; a fourth indicator143designates the other of the second groups127at the first end101and the third group128at the second end102. In the example shown inFIG. 12, three indicators190,191,193are used to designate the groups on each side of the circuit150. A first indicator190designates the first group174at the first end151and the third group178at the second end152; a second indicator191designates one of the second groups175at the first end151and the fourth group179at the second end152; and a third indicator193designates the other of the second groups177at the first end151and the fifth group180at the second end152. In other examples, however, each indicator in the optical circuit120,170could be unique.

FIG. 45shows another optical cable assembly400that is not manufactured using the flexible substrate. Rather, optical lines extends between one or more input connectors IC and one or more output connectors OC. The optical cable assembly400also includes monitoring lines terminated at monitoring connectors M1, M2. The connectors IC, OC, M1, M2are optically coupled to each other at one or more optical couplers at a coupler region C.

In certain examples, the input connector IC may be spliced to the coupler(s) at a first splice S1. For example, one or more fiber lines402extending from the input connector(s) IC may be spliced to fiber lines404extending from a first side of the coupler region C. The output connectors OC may be spliced to the coupler(s) at a second splice S2. For example, one or more fiber lines408extending from the output connector(s) OC may be spliced to fiber lines406extending from an opposite, second side of the coupler region C. The monitoring connectors M1, M2also may be spliced to the coupler(s) at the second splice S2. For example, the monitoring lines410,412may be spliced to the fiber lines406extending from the second side of the coupler region C.

As noted above, the terms input and output are not intended to be limiting; each input connectors IC can be associated with either a transmit signal Tx or a receive signal Rx and each output connectors OC can be associated with either a transmit signal Tx or a receive signal Rx. First monitoring lines410are optically coupled to the connectors IC, OC associated with the transmit signals. The first monitor lines410may be terminated at one or more first monitor connectors M1. Optionally, second monitor lines412are optically coupled to the connectors IC, OC associated with the receive signals. The second monitor lines412may be terminated at one or more second monitor connectors M2. Cables400with only first monitoring lines410are considered “unidirectional cables” while cables400with both first and second monitoring lines410,412are considered “bidirectional cables.”

For ease in viewing inFIG. 45, the cable assembly400is shown with one input connector IC, one output connector OC, one first monitoring connector M1, and one second monitoring connector M2. Only a single line is shown extending from each connector IC, OC, M1, M2inFIG. 45. However, each line represent one or more optical fibers extending from each connector. Further, in certain implementations, the cable assembly400include multiple input connectors IC. In certain examples, the multiple input connectors IC are single-fiber connectors; the output connector OC and monitoring connectors M1, M2are multi-fiber connectors.

Similar to the cable assemblies100,150, each coupler at the coupler region C has a first coupler input line, a first coupler output line, and a second coupler output line. In bidirectional cable assemblies400, each coupler also has a second coupler input line. Each coupler receives a transmit signal at the first coupler input line. If the first coupler input line is optically coupled to an input connector IC, then the first coupler output line is optically coupled to an output connector OC and the second coupler output line is optically coupled to a first monitoring connector M1. If the first coupler input line is optically coupled to an output connector OC, however, then the first coupler output line is optically coupled to an input connector IC and the second coupler output line is optically coupled to the first monitoring connector M1.

Optical Cassette

FIGS. 17-29illustrate an example optical cassette200in which the optical cable assembly100,150can be routed.FIGS. 30-44illustrate another example optical cassette300in which the optical cable assembly100,150can be routed. Alternatively, the optical lines of the cable assembly100,150can be separately mounted with the cassette200,300without first forming the cable assembly.

The optical cassette200,300has a length extending between a front201,301, and a rear202,302, a width extending between a first side203,303and a second side204,304, and a height extending between a top205,305and a bottom206,306. In some implementations, input lines of the cassette200,300are accessible at the front201,301, output lines are accessible at the rear202,302, and monitoring lines are accessible at the rear202,302. Other arrangements are possible.

The optical cassette200,300includes a body207,307defining an interior208(seeFIG. 19). At least part of the interior208of the body207,307is separated into a first level L1and a second level L2along the height. A cover219,3019mounts to the body207,307to close the interior208. In certain examples, the cover219,319is removable from the body207,307. In certain examples, the cover219,319latches to the body207,307. In certain examples, the cover219,319is fastened to the body207,307using one or more fasteners (e.g., screws).

The optical cassette200,300includes a first termination region210,310defined at the first end201,301of the cassette200,300. In certain implementations, the optical cassette200,300includes a second termination region211,311defined at the second end202,302of the cassette200,300. A cable routing region212,312is disposed within the interior208,308of the body207,307between the first and second termination regions210,211,310,311. An optical splice holding region213,313is disposed within the interior208of the body207,307between the first and second termination regions210,211,310,311. An optical coupler holding region214,314is disposed within the interior208,308of the body207,307between the first and second termination regions210,211,310,311.

In certain implementations, the cable routing region212,312is disposed at the first level L1within the body207,307and the optical coupler holding region214,314is disposed at the second level L2within the body207,307. In certain examples, the optical splice holding region213,313also is disposed at the second level L2within the body207,307. In certain examples, one or more optical splices also may be disposed at the first level L1of the body207,307. For example, one or more optical splices may be disposed within the cable routing region212,312.

In the example shown inFIGS. 19 and 35, the first and second levels L1, L2within the body207,307are separated by a divider tray215,315. The first level L1is defined by the body207,307and the second level L2is defined by the divider tray215,315.

The divider tray215,315is removably coupled to the body207,307. In certain implementations, the divider tray215,315is movable relative to the body207,307between open and closed positions. In an example, the divider tray215,315is pivotal relative to the body207,307between the open and closed positions. When in the closed position, the divider tray215,315covers the first level L1(seeFIGS. 20 and 31). When in the open position, the divider tray215,315provides access to the first level L1(seeFIG. 24).

FIGS. 21 and 35illustrates example cassette bodies207,307that defines the first termination region210,310, the second termination region211,311, and the cable routing region212,312. The body207,307includes a base221,321extending between the front201,301and rear202,302of the cassette200,300and extending between the first and second sides203,204,303,304of the cassette200,300. Sidewalls222,322extend upwardly from the base221,321along the first and second sides203,204,303,304.

The body207,307defines an open front223extending between the sidewalls222,322. The body207,307also defines an open rear224. One or more optical adapters250,350can be disposed at the open front223to form the first termination region210,310. In some examples, the optical adapters250,350include single-fiber adapters (e.g., LC adapters, SC adapters, etc.). In other examples, the optical adapters250,350include multi-fiber adapters (e.g., MPO adapters). In certain examples, the adapters250,350are formed as one or more adapter blocks defining a plurality of front and rear ports.

The optical adapters250,350may snap-fit to the cassette body207,307. For example, the body207,307may define apertures231,331through the sidewalls222,322of the body207,307. Certain example adapters250,350are formed in blocks that have ramped shoulders357at opposite ends. As an adapter block250,350is slid into the termination region210,310of the body207,307, the sidewall222,322flexes outwardly over the ramp258,358until the shoulder259,359aligns with the aperture231,331. The sidewall222,322then snaps over the shoulder259,359to hold the adapter block250,350at the body207,307.

In certain implementations, the cover319of the optical cassette300includes a securing arrangement316that inhibits removal of the adapter blocks350from the cassette body307. The securing arrangement316includes a first portion317extending over the sidewall322of the body307and a second portion318extending downwardly from the first portion317and over a portion of the sidewall322(seeFIGS. 32A and 32B). Accordingly, when the cover319is mounted to the body307, the securing arrangement316inhibits outward flexing of the sidewall322, which prevents unlatching of the adapter block350from the body307. In certain examples, the cover319has a securement arrangement316at opposite sides of the cover319to hold the adapter blocks350at opposite sides of the body cassette307.

One or more optical adapters252,254,256,352,354can be disposed at the open rear224to form the second termination region211,311. In some examples, the optical adapters252,254,256,352,354include single-fiber adapters (e.g., LC adapters, SC adapters, etc.). In other examples, the optical adapters252,254,256,352,354include multi-fiber adapters (e.g., MPO adapters). In certain examples, the adapters252,254,256,352,354are formed as one or more adapter blocks defining a plurality of front and rear ports.

In certain implementations, the adapters252,254,256,352,354at the second termination region211,311are a different type from the adapters250,350at the first termination region210,310. In the example shown, the adapters250,350at the first termination region210,310are single-fiber adapters and the adapters252,254,256,352,354at the second termination region211,311are multi-fiber adapters.

In certain implementations, one or more dividing walls225,325can separate the open rear224into two or more adapter locations. An adapter or adapter block252,254,256,352,354can be disposed at each adapter location. In certain implementations, one or more dividing walls226,326can separate the open front223into two or more adapter locations. An adapter or adapter block250,350can be disposed at each adapter location.

One or more guide members (e.g., bend radius limiters, spools, etc.) can be disposed on the base221,321to guide optical fibers along the first level of the body207,307. In certain examples, one or more bend radius limiters227,327extend upwardly from the base221,321. In certain implementations, retention fingers229extend outwardly from the bend radius limiters227,327to aid in retaining the optical fibers on the first level. In certain examples, the retention fingers229are removable from the bend radius limiters227,327to aid in cabling the fibers on the first level. For example, the retention fingers229may be coupled to a central hub228that mounts to a bend radius limiter227,327(seeFIG. 20).

In certain implementations, the base212,312defines one or more splice retention stations212a,312ato retain optical splices at the cable routing region212,312. In the example shown, each splice retention stations212adefines a recess in the base212,312. In other implementations, each splice retention stations212a,312amay include fingers to pinch the optical splice, walls between which the splice may be friction fit, or other retaining structures. In the example shown, the retention stations212a,312aare angled relative to the front201,301and rear202,302of the cassette200,300.

In certain implementations, the body207,307is configured to manage cables coupled to exterior ports of the second termination field211,311. For example, the body207,307may be configured to inhibit excessive bending of the cables as the cables extend away from the second termination field211,311. In certain examples, the body207,307is configured to inhibit excessive bending as the cassette200,300moves relative to a rack to which the cables are anchored.

In certain implementations, the body207,307includes a guide arrangement230,330extending rearwardly from the rear202,302of the cassette200,300. In certain examples, the body207,307includes a first guide arrangement230,330extending rearwardly from the first side203,303of the rear202,302and a second guide arrangement230,330extending rearwardly from the second side204,304of the rear202,302. In certain examples, the second termination region211,311is disposed between the first and second guide arrangement230,330.

Each guide arrangement230,330defines a channel232,323extending between an entrance233,333and an exit234,334. One or more bend radius limiters236,336are disposed within the channel232,332to inhibit excessive bending of any cable routed through the channel232,332. One or more tabs238,338may extend over the channel232,332to aid in holding the cable within the channel232,332.

In certain implementations, the entrance233,333faces in a different direction from the exit234,334. In certain implementations, the entrance233,333faces towards one of the sides203,204,303,304of the cassette200,300and the exit234,334faces towards the other side204,203,304,303. In certain examples, the entrances233,333of the guide arrangements230,330face each other. In an example, the channel232,332has an S-shape. In certain examples, the entrances233,333are disposed at the rear of the guide arrangements230,330. In certain examples, the exits234,334are disposed at the front of the guide arrangements230,330. Accordingly, a cable may extend rearwardly from the second termination region211,311along the guide arrangement230,330, enter the channel232,332at the entrance233,333of the guide arrangement230,330, extend through the channel232,332around the bend radius limiters236,336, and exit the channel232,332at one side203,204,303,304of the body207,307.

FIGS. 33 and 34show the differences between the guide arrangements230and the guide arrangement330. The channel332of the guide arrangement330ofFIG. 34is narrower than the channel232of the guide arrangement230shown inFIG. 33. The narrower channel332may facilitate sliding of the cassette300within a chassis or other housing. InFIGS. 33 and 34, the cassettes200,300are shown mounted on a tray having a cable guide member410relative to which the cassettes200,300can slide. The guide arrangements230also have open sections (i.e., interruptions in the sidewalls) adjacent the rearward radius limiters336compared to the guide arrangements230. Accordingly, cables450leaving the guide arrangement330have more clearance than the cables450leaving the guide arrangement230.

FIGS. 22 and 35illustrates an example divider tray215,315includes a base218that defines the optical splice holding region213,313and the optical coupler holding region214,314. The divider tray215,315includes one or more mounting members216that secure to the body207,307of the cassette200,300. In the example shown, the mounting members216define hinge pins209that mounts within a mounting recess220defined in the body207,307. The divider tray215,315pivots about the hinge pins209. In certain examples, the divider tray215,315includes a grip member217,317at an opposite end from the mounting members216.

In certain implementations, the splice holding region213,313and the coupler holding region214,314are disposed along a central region of the divider tray215,315. In certain examples, the splice holding region213,313is disposed closer to the mounting members216and the coupler holding region214,314is disposed closer to the grip member217,317. The splice holding region213,313is configured to hold a plurality of optical splices. In the example shown, the optical splices are held so that fibers extending from opposite ends of the splices extend towards the sides203,204,303,304of the cassette200,300. The coupler holding region214,314is configured to hold a plurality of optical couplers. In the example shown, the optical couplers are held so that fibers extending from opposite ends of the couplers extend towards the sides203,204,303,304of the cassette200,300.

In certain implementations, the divider tray215,315defines first and second entrances/exits240,241,340,341at the front end of the tray215,315. For example, the first entrance/exit240,340may be disposed at the front of the tray215,315towards the first side203,303of the cassette200,300and the second entrance/exit241,341may be disposed at the front of the tray215,315towards the second side204,304of the cassette200,300. A guide channel242,342extends around a periphery of the divider tray215,315between the first and second entrances/exits240,241,340,341.

One or more bend radius limiters are disposed along the guide channel242,342to guide the optical fibers around the divider tray215,315. In certain implementations, the bend radius limiters include a first set of spools243,343disposed closer to the entrances/exits240,241,340,341and a second set of spools244,344disposed further from the entrances/exits240,241,340,341. In certain examples, each of the spools244,344of the second set defines a bypass channel245,345that guides one or more fibers through the spool244,344instead of around the spool244,344. Retention tabs may extend over the guide channel242,342, outwardly from any of the spools243,244,343,344, and/or over the bypass channel245,345.

First passages246each lead between the splice holding region213,313and the guide channel242,342at a respective one of the entrances/exits240,241,340,341. Second passages247lead between the coupler holding region214,314and the guide channel242,342. Each second passage247extends between a spool243,343from the first set and a spool244,344from the second set. Retaining fingers may extend over the first and second passages246,247.

In some implementations, any of the cable assemblies100,150disclosed herein can be routed within the cassette200,300. For example, the input connector(s)133,183may be plugged into the rear port(s) of the optical adapter(s)250,350at the first termination region210,310. The output connector136,186may be plugged into the front port of the optical adapter252,352at the second termination region211,311. The monitoring connector137,187that monitors signals received at the input connector(s)133,183may be plugged into a front port of the adapter254,354at the second termination region211,311. If the cable assembly100includes bidirectional couplers110, then the monitoring connector138that monitors signals received at the output connector136,186may be plugged into a front port of the adapter256,356at the second termination region211,311.

If the input connectors133,183are optically spliced to the remainder of the cable assembly100,150, then the optical splices134,184may be disposed in the splice retention stations212ain the cable routing region212,312on the first level L1of the cassette200,300.

The optical couplers110,160of the cable assembly100,150are mounted to the optical coupler holding region214,314on the second level L2of the cassette200,300. For example, the optical couplers110,160may be mounted to the divider tray215,315. In certain examples, the optical couplers110,160are mounted so that the coupler input lines112,162extend towards the same side as the first entrance/exit240,340of the divider tray215,315and the coupler output lines114,164extend towards the same side as the second entrance/exit241,341of the divider tray215,315. In certain examples, the couplers110,160are oriented such that the coupler input fibers112,162and coupler output fibers114,164extend from the couplers110,160, through the second passages247, to the guide channel242,342.

The optical splices145-147,194,195,197of the cable assembly100,150are mounted to the optical splice holding region213,313on the second level L2of the cassette200,300. For example, the optical splices145-147,194,195,197may be mounted to the divider tray215,315. In certain examples, the optical splices145-147,194,195,197are mounted so that the free ends133,163of the coupler input fibers112,162and free ends115,117of the coupler output fibers114,116extend in a first direction from the optical splices, through one of the first passages246, to the guide channel242,342. First and second groups124-127of the optical circuit120,170extend in a second direction from the optical splices145-147,194,195,197, through another of the first passages246, to the guide channel242,342.

In some implementations, an optical cassette200,300holds a single cable assembly100,150. In other implementations, an optical cassette200,300holds multiple cable assemblies100,150. In certain implementations, a first cable assembly100,150can be mounted primarily at a first side of the cassette200,300and a second cable assembly100,150can be mounted primarily at a second side of the cassette200,300. For example, the input connectors133,183of the first cable assembly100,150may be mounted at a first side of the first termination region210,310and the input connectors133,183of the second cable assembly100,150may be mounted at a second side of the first termination region210,310.

In some implementations, the splice region213includes a plurality of support members between which the optical splices may be mounted (e.g., seeFIG. 22). In other implementations, the splice region313includes a dividing wall313athat separates out the splice region313into two sections (e.g., seeFIG. 35). In certain examples, the optical splices144of the first cable assembly100,150are disposed at a first of the sections and the optical splices144of the second cable assembly100,150are disposed at a second of the sections as will be described in more detail herein.

In certain implementations, like connectors of the cable assemblies100,150may be grouped together at the second termination region211,311. For example, the output connectors136,186of two or more cable assemblies100,150may be mounted at the same adapter or adapter block256,356at the second termination region211,311while the monitoring connectors137,187may be mounted at a common adapter or adapter block254,354at the second termination region211,311. In cables100with bidirectional couplers110, the monitoring connectors138of the cables100may be mounted at a common adapter or adapter block256,356at the second termination region211,311.

FIGS. 25-27illustrate an example routing scheme for a cable assembly100,150within the cassette200. As shown inFIG. 25, the input connectors133,183of a first cable assembly100,150are plugged into rear ports of optical adapters250at the first termination region210. In certain examples, the input connectors133,183are plugged into the rear ports of the optical adapters250at one side of the first termination region210.

The fibers terminated by the input connectors133,183are routed through the cable routing region212and towards the front201of the cassette200. For example, stub fibers134,184terminated by the input connectors133,183may be wound around a bend radius limiter227at the cable routing region212. An optical splice135,185that optically couples the stub fibers134,184to a third group128,178of fibers of the optical circuit120,170may be disposed at the splice retention station212a. The third group128,178of fibers of the optical circuit120,170is routed towards the front201of the cassette200. After the splice135is secured at the retention station212a, the third group128,178is further wound around the bend radius limiter227before transitioning to the second level L2.

As shown inFIG. 26, the output connector136,186of the cable assembly100,150is plugged into a front port of an output optical adapter252at the second termination region211. The monitoring connector137,187of the cable assembly100,150is plugged into a front port of a first monitor optical adapter254at the second termination region211. In certain examples, the output connector136,186is plugged into one of two rear ports of the output optical adapter252and the monitoring connector137,187is plugged into one of two rear ports of the monitor optical adapter254. In certain examples, a second monitor connector138,188is plugged into a front port of a second monitor optical adapter256.

The fourth group129,179of the second ends of the fibers121,171of the optical circuit120,170is routed from the output connector136,186and wound around the bend radius limiter227with the stub fibers134,184(or other input lines). The fifth group130,180of the second ends of the fibers121,171of the optical circuit120,170is routed from the monitoring connector136,186and wound around the bend radius limiter227with the fourth group129,179and the stub fibers134,184(or other input lines).

In certain implementations, the substrate139,189has been removed from the optical circuit120,170. Accordingly, the optical fibers121,171of the optical circuit120,170are freely bendable and movable by the user. As the optical circuit120,170is routed through the cable routing region212and/or between the first level L1and the second level L2, the optical fibers121,171transition from the third, fourth, fifth, and sixth groups128-131,178-180to the first and second groups125-127,174,175,177. For example, the optical circuit120,170may be routed onto the divider tray215through one of the entrances/exits240,241.

As shown inFIGS. 27 and 28, the first and second groups125-127,174,175,177are routed over the second level L2of the cassette. The first and second groups125-127,174,175,177are routed at least partially around one of the first bend radius limiters243of the divider tray215, through one of the second passages247, to the optical splice holding region213.

An optical splice144,194between the first group124,174and the coupler input fibers112,162is mounted at the optical splice holding region213. The coupler input fibers112,162are routed from the optical splice holding region213, through one of the first passages246, around one of the bend radius limiters243, through one of the second passages247, to the optical coupler holding region214. The optical coupler110,160from which the coupler input fibers112,162extend is mounted at the optical coupler holding region214.

An optical splice145,195between the second group125,175and some of the coupler output fibers114,116,164,166is mounted at the optical splice holding region213. The coupler output fibers114,116,164,166are routed from the optical splice holding region213, through one of the first passages246, around one of the bend radius limiters243, and around the tray215to an opposite side of the optical splice holding region214. For example, the coupler output fibers114,116,164,166may be routed from the first bend radius limiter243, through the guide channel242, through the bypass channel245in one of the second bend radius limiters244, further along the guide channel242past the optical splice holding region214, around another of the second bend radius limiters244, through another of the second passages247, to the optical coupler holding region214at which the optical coupler110,160from which the some of the coupler output fibers114,116,164,166extend is mounted.

An optical splice147,197between another of the second groups127,177and others of the coupler output fibers114,116,164,166is mounted at the optical splice holding region213. The coupler output fibers114,116,164,166are routed from the optical splice holding region213, through one of the first passages246, around one of the bend radius limiters243, and around the tray215to an opposite side of the optical splice holding region214. For example, the coupler output fibers114,116,164,166may be routed from the first bend radius limiter243, through the guide channel242, through the bypass channel245in one of the second bend radius limiters244, further along the guide channel242past the optical splice holding region214, around another of the second bend radius limiters244, through another of the second passages247, to the optical coupler holding region214at which the optical coupler110,160from which the others of the coupler output fibers114,116,164,166extend is mounted.

In certain implementations, a second cable assembly100,150also can be installed within the cassette200. In certain examples, the input connectors133,183of the second cable assembly100,150may be plugged into the rear ports of the optical adapters250at an opposite side of the first termination region210from the input connectors133,183of the first cable assembly100,150. In certain examples, the output connector136,186of the second cable assembly100,150is plugged into the other of the two rear ports of the output optical adapter252and the monitoring connector137,187is plugged into the other of the two rear ports of the monitor optical adapter254.

As shown inFIG. 29, the second cable assembly100,150is routed in a mirror image of the first cable assembly100,150. For ease in viewing, the first cable assembly100,150is not visible inFIG. 29. The optical circuit120,170of the second cable assembly100,150may be routed onto the divider tray215using the other entrance/exit241,240. In certain implementations, the couplers110,160and optical splices144,145,146,147,194,195,197of the second cable assembly100,150are rotated 180° relative to the couplers110,160and optical splices144,145,146,147,194,195,197of the first cable assembly100,150to accommodate the mirrored cable routing. In certain examples, the couplers110,160of the first cable assembly100,150form a first row at the optical coupler holding region214and the couplers110,160of the second cable assembly100,150form a second row disposed over the first row at the optical coupler holding region214.

FIGS. 36-44illustrate example routing schemes for a cable assembly100,150,400within the cassette300.FIGS. 36-39show the routing for a first cable assembly100,150,400within the cassette.FIGS. 40-42show the routing for a second cable assembly100,150,400within the cassette. InFIGS. 36 and 40, the first and second cable assemblies100,150,400are unidirectional cable assemblies.FIGS. 43 and 44show the cable routing on the first level L1of the cassette300when the first and second cable assemblies100,150,400are bidirectional cable assemblies.

As shown inFIG. 36, the input connectors133,183, IC of a first cable assembly100,150,400are plugged into rear ports of optical adapters350at the first termination region310. In certain examples, the input connectors133,183, IC are plugged into the rear ports of the optical adapters350at one side of the first termination region310.

Stub fibers134,184,402terminated by the input connectors133,183, IC may be wound around a bend radius limiter327at the cable routing region312. One or more optical splices135,185, S1that optically couples the input connectors133,183, IC to the optical couplers110,160may be disposed at the splice retention station312a. In certain examples, the optical splice(s)135,185optically couple the stub fibers134,184to the third group128,178of fibers of the optical cable assembly100,150. In certain examples, the optical splice(s) S1optically couples the input fibers402to the fibers406at the first side of the coupler region C.

The third group128,178of fibers (or fibers406) is routed towards the front301of the cassette300. For example, the third group128,178(or fibers406) may be wound around the bend radius limiter327one or more times. The third group128,178(or fibers406) can then be transitioned to the second level L2by entering the divider tray315through one of the entrances/exits340,341.

As further shown inFIG. 36, the output connector136,186, OC of the cable assembly100,150,400is plugged into a front port of an output optical adapter352at the second termination region311. The first monitoring connector137,187, M1of the cable assembly100,150,400is plugged into a front port of a first monitor optical adapter354at the second termination region311. In certain examples, a second monitor connector138,188, M2may be plugged into a front port of a second monitor optical adapter356(e.g., seeFIG. 44). The fourth group129,179of fibers121,171(or fibers408) and the fifth group130,180of fibers121,171(or fibers410) are routed from the second termination region311, wound one or more times around one of the bend radius limiters327, and routed towards the front301of the cassette300. The fourth and fifth groups129,179,130,180of fibers (or fibers410,412) can then be transitioned to the second level L2by entering the divider tray315through one of the entrances/exits340,341.

In the example shown inFIG. 36, the fourth and fifth groups129,179,130,180of fibers (or fibers410,412) are wound around a different bend radius limiter327than the third group128,178of fibers (or fibers404). In the example shown, the fourth and fifth groups129,179,130,180(or fibers408,410) enter the divider tray315through a different entrance/exit340,341than the third group128,178(or fibers404).

As shown inFIGS. 37 and 38, the third group128,178(or fibers404), the fourth group129,179(or fibers408), and the fifth group130,180(or fibers410) of the optical circuit are routed over the second level L2of the cassette300. As shown inFIG. 37, the third fiber group128,178(or fibers404) are routed from the second entrance341, through guide channel342, to one side of the coupler region C. The fourth and fifth fiber groups129,179,130,180(or fibers408,410) are routed from the first entrance340, through the guide channel342, through bypass channels345, at least partially around one of the first bend radius limiters343, to the optical splice holding region313. In certain examples, the fibers404enter the coupler holding region314, C and the fibers408,410,412enter the splice holding region313from a common side of the divider tray315.

In certain examples, the fourth and fifth fiber groups129,179,130,180(or fibers408,410,412) of a first cable assembly400are routed to a first section of the splice holding region313(e.g., seeFIG. 37) and the fourth and fifth fiber groups129,179,130,180(or fibers408,410,412) of a second cable assembly400are routed to a second section of the splice holding region313(e.g., seeFIG. 41).

As shown inFIG. 38, the optical lines are routed between the splice holding region313, S2and the coupler holding region314, C. For ease in viewing, the fibers shown routed inFIG. 37are hidden from view. In certain examples, inFIG. 38, the coupler input fibers112,162extend between the splice holding region313and the coupler holding region314. In certain examples, the fibers406extend between the second splice region S2and the coupler holding region C. One or more optical splices144,194between the fibers124-127,174-177,408,410,412and the coupler input and output fibers112,114,162,164,406are disposed at the splice holding region313, S2.

FIG. 39illustrates one example configuration of couplers110,160disposed at the coupler holding region314, C. In the example shown, the couplers110,160are mounted in two rows. A first layer of adhesive111holds a bottom row of couplers110,160to the divider tray315. A second layer of adhesive holds an upper row of couplers110,160to the bottom row.

As shown inFIGS. 41 and 42, a second cable assembly400can be mounted to the cassette300in a mirror configuration from the first cable assembly400. The fibers404of the second cable assembly400extend from the first entrance340of the divider tray315to the coupler holding region314, C. The fibers408,410,412of the second cable assembly400extend from the second entrance341of the divider tray315to the splice holding region313. In certain examples, the fibers404enter the coupler holding region314, C and the fibers408,410,412enter the splice holding region313from a common side of the divider tray315.

As shown inFIGS. 43 and 44, bidirectional cables100,400include an output connector136, OC, a first monitoring connector137, M1, and a second monitoring connector138, M2received at the second termination region311. The output lines136,408and monitoring lines137,138,410,412are routed around a bend radius limiter327and towards the front301of the cassette to be transitioned to the second level L2. The input lines134,402are routed to a splice retention station312a, S1at which the input lines402are spliced to coupler input and/or output lines112,114,404. The coupler input output lines112,114,404are routed around another bend radius limiter327and towards the front301of the cassette300to be transitioned to the second level L2. The routing on the second level L2for the first of the bidirectional cable100,400ofFIG. 43is shown inFIGS. 37 and 38. The routing on the second level L2for the second of the bidirectional cable100,400ofFIG. 44is shown inFIGS. 41 and 42.

Having described the preferred aspects and implementations of the present disclosure, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.

Other Aspects of the Disclosure

Aspect 1. An optical cable assembly comprising:

a plurality of optical couplers, each optical coupler having at least one coupler input fiber, a first coupler output fiber, and a second coupler output fiber;

a plurality of optical fibers adhesively laid on a substrate to form an optical circuit, each optical fiber extending from an unterminated first end to an unterminated second end, the optical circuit separating the unterminated first ends of the optical fibers into a plurality of groups including a first group and a second group, the first group of the unterminated first ends being spliced to free ends of at least some of the coupler input fibers, the second group of the unterminated first ends being spliced to free ends of at least some of the first and second coupler output fibers, the optical circuit also separating the unterminated second ends of the optical fibers into another plurality of groups including a third group, a fourth group, and a fifth group;

one or more input plug connectors terminating the third group of the unterminated second ends to optically couple the one or more input plug connectors to at least some of the input coupler fibers;

one or more output plug connectors terminating the fourth group of the unterminated second ends to optically couple the one or more output plug connectors to at least some of the output coupler fibers; and

one or more monitor plug connectors terminating the fifth group of the unterminated second ends to optically couple the one or more monitor plug connectors to others of the output coupler fibers.

Aspect 2. An optical cable assembly comprising:

a plurality of optical couplers, each optical coupler having at least one coupler input fiber, a first coupler output fiber, and a second coupler output fiber;

an optical circuit having been manufactured on a flexible substrate, the optical circuit including a plurality of optical fibers, each optical fiber extending from an unterminated first end to an unterminated second end and being free to flex along a length of the optical fiber, the optical circuit separating the unterminated first ends of the optical fibers into a plurality of ribbonized groups including a first group and a second group, the first group of the unterminated first ends being spliced to free ends of at least some of the coupler input fibers, the second group of the unterminated first ends being spliced to free ends of at least some of the first and second coupler output fibers, the optical circuit also separating the unterminated second ends of the optical fibers into another plurality of ribbonized groups including a third group, a fourth group, and a fifth group;

one or more input plug connectors terminating the third group of the unterminated second ends to optically couple the one or more input plug connectors to at least some of the input coupler fibers after removing the flexible substrate;

one or more output plug connectors terminating the fourth group of the unterminated second ends to optically couple the one or more output plug connectors to at least some of the output coupler fibers after removing the flexible substrate; and

one or more monitor plug connectors terminating the fifth group of the unterminated second ends to optically couple the one or more monitor plug connectors to others of the output coupler fibers after removing the flexible substrate.

Aspect 3. The optical cable assembly of Aspect 1 or Aspect 2, wherein the one or more input plug connectors include one multi-fiber plug connector that receives all of the second ends of the third group.

Aspect 4. The optical cable assembly of Aspect 1 or Aspect 2, wherein the one or more input plug connectors include a plurality of single-fiber plug connectors that each receive a respective one of the second ends of the third group.

Aspect 5. The optical cable assembly of Aspect 1 or Aspect 2, wherein the one or more input plug connectors include a plurality of duplex-fiber plug connectors that each receive a respective pair of the second ends of the third group.

Aspect 6. The optical cable assembly of Aspect 1 or Aspect 2, wherein the one or more output plug connectors include one multi-fiber plug connector that receives all of the second ends of the fourth group.

Aspect 7. The optical cable assembly of Aspect 1 or Aspect 2, wherein the one or more monitor plug connectors include one multi-fiber plug connector that receives all of the second ends of the fifth group.

Aspect 8. The optical cable assembly of any of Aspects 1-7, wherein each optical coupler includes only a single coupler input fiber.

Aspect 9. The optical cable assembly of any of Aspects 1-7, wherein each optical coupler includes a pair of coupler input fibers.

Aspect 10. The optical cable assembly of Aspect 1 or Aspect 2, wherein the input plug connectors are optically coupled to all of the input coupler fibers.

Aspect 11. A method of assembling an optical cable assembly including a plurality of optical couplers, each optical coupler having at least one coupler input fiber, a first coupler output fiber, and a second coupler output fiber, the method comprising:

laying a plurality of optical fibers into an adhesive layer on a substrate to form an optical circuit, each optical fiber extending from an unterminated first end to an unterminated second end, the optical circuit separating the unterminated first ends of the optical fibers into a plurality of groups including a first group and a second group, the optical circuit also separating the unterminated second ends of the optical fibers into another plurality of groups including a third group, a fourth group, and a fifth group;

splicing the first group of the unterminated first ends to free ends of at least some of the coupler input fibers;

splicing the second group of the unterminated first ends to free ends of at least some of the first and second coupler output fibers;

terminating the third group of the unterminated second ends to one or more input plug connectors to optically couple the one or more input plug connectors to at least some of the input coupler fibers;

terminating the fourth group of the unterminated second ends to one or more output plug connectors to optically couple the one or more output plug connectors to at least some of the output coupler fibers; and

terminating the fifth group of the unterminated second ends to one or more monitor plug connectors to optically couple the one or more monitor plug connectors to others of the output coupler fibers;

removing the substrate from the optical circuit.

Aspect 12. The method of Aspect 11, wherein each optical coupler includes a pair of coupler input fibers.

Aspect 13. The method of Aspect 11, wherein the another plurality of groups also includes a sixth group; and wherein the method further comprises

terminating the sixth group of the unterminated second ends to one or more second monitor plug connectors to optically couple the one or more second monitor plug connectors to others of the input coupler fibers.

Aspect 14. The method of Aspect 11, further comprising:

ribbonizing the free ends of the coupler input fibers prior to splicing the free ends of the coupler input fibers to the first group of the unterminated first ends; and

ribbonizing the free ends of the first and second coupler output fibers prior to splicing the second group of the unterminated first ends to free ends of the first and second coupler output fibers.

Aspect 15. The method of Aspect 11, wherein the optical circuit separates the unterminated first ends of the optical fibers into the plurality of groups also including a seventh group and an eighth group; and wherein the method further comprises:

splicing the seventh group of the unterminated first ends to free ends of others of the coupler input fibers;

splicing the eighth group of the unterminated first ends to free ends of others of the first and second coupler output fibers.