WO2021183488A1

WO2021183488A1 - Fiber optic circulator connectors

Info

Publication number: WO2021183488A1
Application number: PCT/US2021/021468
Authority: WO
Inventors: Ming Zhen HU; Li Song; Man Kit Joe WONG
Original assignee: Senko Advanced Components, Inc.
Priority date: 2020-03-13
Filing date: 2021-03-09
Publication date: 2021-09-16

Abstract

An optical converter unit converts dedicated transmission and receiving optical pathways into a single bi-directional transmission and receiving pathway. The converter unit includes a fiber optic circulator having a receiving port, a transmission port, and a bi-directional port. A bi-directional interface mechanically couples to a first optical waveguide to optically connect the first optical waveguide to the bi-directional port so that optical signals are transmitted to the first optical waveguide and received from the first optical waveguide via the bi-directional port. A transmission and receiving interface mechanically couples to a second optical waveguide to optically connect the second optical waveguide to the transmission port to transmit optical signals to the second optical waveguide. The transmission and receiving interface also mechanically couples to a third optical waveguide to optically connect the third optical waveguide to the receiving port for sending optical signals to the receiving port.

Description

FIBER OPTIC CIRCULATOR CONNECTORS

FIELD

[0001] The present disclosure generally relates to fiber optic connections, and, more specifically, to fiber optic connections including fiber optic circulators.

BACKGROUND

[0002] Optical connectors are used within optical communication networks to interconnect optical cables to optical devices, such as optical transceivers. For example, two optical transceivers may be communicatively coupled together by an optical cable containing two or more optical fibers. The optical cable includes an optical connector at each end for connecting to and forming an optical connection with each optical transceiver, thereby optically coupling the two optical transceivers to each other.

SUMMARY

[0003] In one aspect, an optical converter unit for converting dedicated transmission and receiving optical pathways into a single bi-directional transmission and receiving pathway comprises a housing having an interior. A fiber optic circulator is disposed in the interior of the housing. The fiber optic circulator has a receiving port configured to receive optical signals, a transmission port configured to transmit optical signals, and a bi-directional port configured to receive and transmit optical signals. A bi-directional interface is supported by the housing. The bi-directional interface is configured to mechanically couple to a first optical waveguide to optically connect the first optical waveguide to the bi-directional port of the fiber optic circulator so that optical signals are transmitted to the first optical waveguide via the bi-directional port and received from the first optical waveguide via the bi-directional port. A transmission and receiving interface is supported by the housing. The transmission and receiving interface is configured to mechanically couple to a second optical waveguide to optically connect the second optical waveguide to the transmission port for transmitting optical signals from the transmission port to the second optical waveguide. The transmission and receiving interface is also configured to mechanically couple to a third optical waveguide to optically connect the third optical waveguide to the receiving port of the fiber optic circulator for receiving optical signals from the third optical waveguide by the receiving port of the fiber optic circulator.

[0004] Other objects and features of the present disclosure will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a perspective of a conventional fiber optic system with two transceivers optically coupled together with two fiber optic cables;

[0006] FIG. 2 is a schematic of the conventional fiber optic system;

[0007] FIG. 3 is a schematic perspective of a fiber optic system according to one embodiment of the present disclosure, the system including two optical converter units for optically coupling two transceivers with a single fiber optic cable;

[0008] FIG. 4 is a schematic of the fiber optic system of Fig. 3 ;

[0009] FIG. 5 is a perspective of an optical converter unit according to one embodiment of the present disclosure;

[0010] FIG. 6 is a top perspective of the optical converter unit of Fig. 5, with a cover removed to show interior details;

[0011] FIG. 7 is a fragment of Fig. 6 with an outer shell of a circulator removed;

[0012] FIG. 8 is a top plan view of the optical converter unit of Fig. 5, with a cover removed to show interior details;

[0013] FIG. 9 is a side view of the optical converter unit of Fig. 5 ;

[0014] FIG. 10 is a perspective of an optical converter unit according to another embodiment of the present disclosure;

[0015] FIG. 11 is a top perspective of the optical converter unit of Fig. 10, with a cover removed to show interior details;

[0016] FIG. 12 is an exploded view of the optical converter unit of Fig. 10;

[0017] FIG. 13 is a schematic of the optical converter unit of Fig. 10;

[0018] FIG. 14 is a perspective of an optical converter unit according to another embodiment of the present disclosure;

[0019] FIG. 15 is a partially exploded view of the optical converter unit of Fig. 14;

[0020] FIG. 16 is another partially exploded view of the optical converter unit of Fig. 14;

[0021] FIG. 17 is a perspective of the optical converter unit of Fig. 14 with a tubular sleeve of the optical converter unit removed to show interior details;

[0022] FIG. 18 is an exploded view of a circulator mount of the optical converter unit of Fig. 14;

[0023] FIG. 19 is an exploded view of an end fitting of the optical converter unit of Fig. 14; [0024] FIG. 20 is a perspective of an optical converter unit according to another embodiment of the present disclosure;

[0025] FIG. 21 is a partially exploded view of the optical converter unit of Fig. 20;

[0026] FIG. 22 is a perspective of the optical converter unit of Fig. 20 with a tubular sleeve of the optical converter unit removed to show interior details;

[0027] FIG. 23 is an exploded view of a circulator mount of the optical converter unit of Fig. 20; and

[0028] FIG. 24 is a perspective of the optical converter unit of Fig. 20 showing retainers of the optical converter exploded from the remainder of the optical converter unit.

[0029] Corresponding reference characters indicate corresponding parts throughout the drawings.

DETAILED DESCRIPTION

[0030] Referring to Figs. 1 and 2, a conventional fiber optic system 1 (e.g., a conventional fiber optic communication network) is shown for optically connecting two transceivers 2. Each transceiver 2 includes a transmission receptacle 3 for sending optical signals and a receiving receptacle 4 for receiving optical signals. The two transceivers 2 are optically coupled together with two fiber optic cables 5. Each fiber optic cable 5 has a single optical pathway that may be formed by one or more optical fibers (not shown). Each cable 5 includes a fiber optic connector 6 at each end for coupling to one of the receptacles 3, 4 in a respective one of the transceivers 2. Each fiber optic cable 5 is coupled to a transmission receptacle 3 of one transceiver 2 and the receiving receptacle 4 of the other transceiver. Each fiber optic cable 5 is dedicated for carrying optical signals in one direction, from the transmission receptacle 3 of one transceiver 2 to the receiving receptacle 4 of the other transceiver. Thus, in this conventional arrangement, two optical cables 5 are required to optical couple the two transceivers 2 together.

[0031] Referring to Figs. 3-9, one embodiment of an optical converter unit according to the present disclosure is generally indicated at reference numeral 10. The optical converter unit 10 is used to form optical communication connections between optical devices (e.g., transceivers 2). The optical converter unit 10 converts dedicated transmission and receiving optical pathways (e.g., transmission receptacle 3, receiving receptacle 4) into a single bi-directional transmission and receiving pathway (e.g., a single fiber optic cable 5). Figs. 3 and 4 illustrated a fiber optic system 12 including two optical converter units 10 for optically connecting the two transceivers

2 with a single fiber optic cable 5. In this configuration, the fiber optic cable 5 carries optical signals in two directions, to and from each transceiver 2. As illustrated, the optical converter unit 10 is used to essentially merge dedicated transmission and receiving optical pathways into a single optical pathway, so that a single optical pathway (e.g., a single fiber optic cable 5) can be used to optically couple two fiber optic devices, instead of two optical pathways (e.g., two fiber optic cables). Thus, the optical converter unit 10 reduces the number of optical pathways (e.g., fiber optic cables 5) needed to optically coupled fiber optic devices together in an optical communications network.

[0032] Referring to Figs. 5-9, the optical converter unit 10 includes a housing 14 having an interior 16. The housing 14 includes a base 18 and a cover 20 attached to the base. In the illustrated embodiment, the cover 20 is attached to the base 18 via a snap-fit connection, although other ways of attaching the cover to the base are within the scope of the present disclosure.

[0033] The optical converter unit 10 includes a fiber optic circulator 22 (broadly, at least one fiber optic circulator). The fiber optic circulator 22 is disposed in the interior 16 of the housing 14. In the illustrated embodiment, the housing 14 (e.g., base 18) includes a snap-fit mount 24 (Fig. 7) for the fiber optic circulator 22. The fiber optic circulator 22 is mounted and held by the snap-fit mount 24. Accordingly, the fiber optic circulator 22 can be considered built- in or integral with the optical converter unit 10. Fiber optic circulators 22 are generally known in the art. The fiber optic circulator 22 has a receiving port 26 (Fig. 4) configured to receive optical signals, a transmission port 28 configured to transmit optical signals and a bi-directional port 30 configured to receive and transmit optical signals. The fiber optic circulator 22 operates such that optical signals received by the receiving port 26 are routed to and transmitted by the bi directional port 30. Similarly, optical signals received by the bi-directional port 30 are routed to and transmitted by the transmission port 28.

[0034] The optical converter unit 10 includes a bi-directional interface 32. The bi directional interface 32 is supported by the housing 14. In the illustrated embodiment, the base 18 supports the bi-directional interface 32. The bi-directional interface 32 is configured to mechanically couple to a first optical waveguide to optically connect the first optical waveguide to the bi-directional port 30 of the fiber optic circulator 22. This allows optical signals to be transmitted to the first optical waveguide via the bi-directional port 30 of the fiber optic circulator 22 and allows optical signals to be received from the first optical waveguide (fiber optic cable 5) via the bi-directional port. In the illustrated embodiment, the optical converter unit 10 includes one or more optical fibers 36 generally extending between the bi-directional interface 32 and the bi-directional port 30 of the fiber optic circulator 22 for optically connecting the first optical waveguide coupled to the bi-directional interface to the fiber optic circulator.

[0035] As used herein, the term "optical waveguide" refers to any component that can do one or more of receive, transmit, carry, etc. optical signals. For example, an optical waveguide can be a fiber optic device (e.g., a transceiver 2, a transmitter, a receiver, a transmitter optical sub-assembly (TOSA), a receiver optical sub-assembly (ROSA), a bi-directional optical sub-assembly (BOSA), etc.), a fiber optic connector, a fiber optic cable, and/or an optical fiber. For example, in the embodiment of the fiber optic system 12 shown in Figs. 3 and 4, the First optical waveguide is a fiber optic cable 5 (specifically, the fiber optic connector 6 at one of the ends of the fiber optic cable). In the illustrated embodiment, the bi-directional interface 32 comprises a fiber optic receptacle 34 (e.g., a single fiber optic receptacle). The fiber optic receptacle 34 is configured to mechanically couple to a fiber optic connector, such as the fiber optic connector 6 of the fiber optic cable 5. The fiber optic receptacle 34 can be configured to couple to generally any type of fiber optic connector. Accordingly, the fiber optic receptacle 34 may have different configurations depending on the type and/or style of the fiber optic connector to which it is designed to connect (e.g., receive). Other configurations of the bi-directional interface are within the scope of the present disclosure. For example, the bi-directional interface may comprise a fiber optic connector that mechanically couples to a fiber optic receptacle.

[0036] The optical converter unit 10 includes a transmission and receiving interface 38. The transmission and receiving interface 38 is supported by the housing 14. In the illustrated embodiment, the base 18 supports the transmission and receiving interface 38. The transmission and receiving interface 38 is configured to mechanically couple to a second optical waveguide to optically connect the second optical waveguide to the transmission port 28 of the fiber optic circulator 22. This allows optical signals to be transmitted to the second optical waveguide from the transmission port 28. In addition, the transmission and receiving interface 38 is also configured to mechanically couple to a third optical waveguide to optically connect the third optical waveguide to the receiving port 26 of the fiber optic circulator 22. This allows optical signals to be received from the third optical waveguide by the receiving port 26. In the illustrated embodiment, the optical converter unit 10 includes one or more optical fibers 40 generally extending between the transmission and receiving interface 38 and the transmission port 28 of the fiber optic circulator 22 for optically connecting the second optical waveguide to the transmission and receiving interface to the fiber optic circulator. The optical converter unit 10 also includes one or more optical fibers 42 generally extending between the transmission and receiving interface 38 and the receiving port 26 of the fiber optic circulator 22 for optically connecting the third optical waveguide coupled to the transmission and receiving interface to the fiber optic circulator. The second and third optical waveguides may be part of the same component (e.g., transceiver 2) or may be part of separate components (e.g., two different fiber optic cables, not shown).

[0037] In the embodiment shown in Figs. 3 and 4, the second and third optical waveguides are part of the transceiver 2. In this case, the second optical waveguide comprises the receiving receptacle 4 of the transceiver 2 and the third optical waveguide comprises the transmission receptacle 3 of the transceiver.

[0038] In the illustrated embodiment, the transmission and receiving interface 38 comprises a transmission or first fiber optic connector 44 and a receiving or second fiber optic connector 46. The transmission fiber optic connector 44 is configured to mechanically connect to the second optical waveguide, such as the receiving receptacle 4 of the transceiver 2. The receiving fiber optic connector 46 is configured to mechanically connect to the third optical waveguide, such as the transmission receptacle 3 of the transceiver 2. The transmission and receiving fiber optic connectors 44, 46 can be configured to couple to generally any type of fiber optic ports or receptacles. Accordingly, the transmission and receiving fiber optic connectors 44, 46 may have different configurations depending on the type and/or style of the fiber optic ports to which each is designed to connect (e.g., be inserted into). Other configurations of the transmission and receiving interface are within the scope of the present disclosure. For example, the transmission and receiving interface can comprise a transmission or first fiber optic receptacle that mechanically connects to the second optical waveguide and a receiving or second fiber optic receptacle that mechanically connects to the third optical waveguide.

[0039] The optical converter unit 10 of Figs. 3-9 may be considered a plug and play optical converter unit. That is, the optical converter unit 10 includes a fiber optic receptacle 34 that can be connected to conventional or existing fiber optic connectors and transmission and receiving fiber optic connectors 44, 46 that can be connected to conventional or existing fiber optic ports or receptacles. This allows the optical converter unit 10 to be installed into existing fiber optic systems, such as the system 1 of Figs. 1 and 2, without any special hardware (e.g., adapters). Stated another way, the optical connector unit 10 is "pluggable".

[0040] Referring to Figs. 10-13, another embodiment of an optical converter unit according to the present disclosure is generally indicated by reference numeral 110. The optical converter unit 110 of Figs. 10-13 is generally analogous to the optical converter unit 10 of Figs. 3-9. Thus, for ease of comprehension, where similar, analogous or identical parts are used, reference numerals "100" units higher are employed. Accordingly, unless clearly stated or indicated otherwise, the above descriptions regarding the optical converter unit 10 of Figs. 3-9 also apply to the optical converter unit 110 of Figs. 10-13. Stated another way, the optical connector unit 10 is "pluggable".

[0041] In this embodiment, the transmission and receiving interface 138 of the optical converter unit 110 comprises a cable port 144. The cable port 144 is configured to permit a fiber optic cable 7 to extend into the interior 116 of the housing 114. The cable port 144 is also configured to mechanically connect to the fiber optic cable 7. For example, the cable port 144 can include cable connection structure such as a clamp, a detent, a collar, a stop, etc. for connecting and secure the fiber optic cable 7 to the housing 114. In this embodiment, the fiber optic cable 7 includes two dedicated optical pathways, each of which may be formed by one or more optical fibers (not shown). One optical pathway of the fiber optic cable 7 is optically connected to the receiving port 126 of the fiber optic circulator 122 via an optical fiber 142. The other optical pathway of the fiber optic cable 7 is optically connected to the transmission port 128 of the fiber optic circulator 122 via another optical fiber 140. Accordingly, in this embodiment, the fiber optic cable 7 incorporates both the second and third optical waveguides (e.g., the two optical pathways of the fiber optic cable).

[0042] In the illustrated embodiment, the optical converter unit 110 includes two sets of optical signal converter components. Each set includes a fiber optic circulator 122, a bi directional interface 132 and a transmission and receiving interface 138. In other words, the optical converter unit 110 includes in total two fiber optic circulators 122, two bi-directional interfaces 132 and two transmission and receiving interfaces 138. It may be preferable for the optical converter unit 110 to include two fiber optic circulators 122, two bi-directional interfaces 132 and two transmission and receiving interfaces 138. For instance, in a plug and play situation - where the optical converter unit 110 is being connected to an existing fiber optic system to enable the exiting fiber optic cables (e.g., existing optical pathways) to carry optical signals in two directions - the two bi-directional interfaces 132 of the optical converter unit can be coupled to the same existing fiber optic cable having two optical pathways. One optical pathway of the existing fiber optic cable is optically connected to the first fiber optic circulator 122 via the first bi-directional interface 132 and the other optical pathway of the existing fiber optic cable is optically connected to the second fiber optic circulator 122 via the second bi-directional interface 132. This way, the existing fiber optic cable which may have been used to optical couple two optical devices (e.g., transceivers 2), with each optical pathway only carrying optical signals in two directions, can now be used to optical couple two sets of two optical devices together. In other words, the optical converter unit 110 allows more fiber optic devices (broadly, optical waveguides) to be connected to an existing fiber optic system without the need to add additional fiber optic cables to the existing system for the additional fiber optic devices by turning existing dedicated, one-way optical pathways into bi-directional optical pathways. As with other embodiments herein, using the optical converter unit 110, the capacity (e.g., total number of fiber optic devices coupled to an existing fiber optic system) of an existing fiber optic system can be doubled without increasing the number of fiber optic cables used, thereby enabling a greater density of optical communications to occur in existing fiber optic systems.

[0043] Referring to Figs. 14-19, another embodiment of an optical converter unit according to the present disclosure is generally indicated by reference numeral 210. The optical converter unit 210 of Figs. 14-19 is generally analogous to the optical converter unit 10 of Figs. 3-9. Thus, for ease of comprehension, where similar, analogous or identical parts are used, reference numerals "200" units higher are employed. Accordingly, unless clearly stated or indicated otherwise, the above descriptions regarding the optical converter unit 10 of Figs. 3-9 also apply to the optical converter unit 210 of Figs. 14-19.

[0044] In this embodiment, the housing 214 is an all-weather (e.g., water-proof housing). The housing 214 includes a tubular sleeve 250. The tubular sleeve 250 has opposite first and second ends. The tubular sleeve 250 defines the interior 216 of the housing 214. The housing 214 also includes first and second end fittings 252, 254 (e.g., end caps). The first end fitting 252 closes (e.g., sealingly closes) the first end of the tubular sleeve 250 (e.g., a first end of the interior 216) and the second end fitting 254 closes (e.g., sealingly closes) the second end of the tubular sleeve (e.g., a second end of the interior). In the illustrated embodiment, the first and second end fittings 252, 254 include gaskets 256. Only one of the gaskets 256 is illustrated in the drawings. Each gasket 256 is configured to engage the tubular sleeve 250 (e.g., an interior surface thereof) to form the seal between the tubular sleeve and the respective end fitting 252, 254.

[0045] The first end fitting 252 supports the bi-directional interface 232. The fiber optic receptacle 234 of the bi-directional interface 232 includes a duct cover or cap 258 (shown attached to the receptacle in the figures). The cap 258 may be threadably coupled to the body of the fiber optic receptacle 234. The cap 258 inhibits particles (e.g., dust) from entering the fiber optic receptacle 234 prior to the attachment of the fiber optic connector. The cap 258 is removed prior to the connection of the fiber optic connector. For reasons that will become apparent, in this embodiment, the single fiber optic receptacle 234 forms two bi-directional interfaces 232 (e.g., two optical pathways are optically connected in the single fiber optic receptacle). [0046] The second end fitting 254 supports the transmission and receiving interface 238. In this embodiment, the transmission and receiving interface 238 of the optical converter unit 210 comprises a fiber optic receptacle 244 (e.g., a single fiber optic receptacle). The fiber optic receptacle 244 of the transmission and receiving interface 238 is configured to mechanically connect to the second and third optical waveguides. Specifically, the fiber optic receptacle 244 of the transmission and receiving interface 238 is configured to mechanically connect to fiber optic connector (not shown) coupled to the second optical waveguide and the third optical waveguide. For example, the second and third optical waveguides can be part of the same fiber optic cable, such as fiber optic cable 7. In this instance, the fiber optic cable 7 includes two optical pathways (one for each optical waveguide) and a single fiber optic connector (not shown) at the end of the cable for forming an optical connection for each optical pathway with the fiber optic receptacle 244 (e.g., the fiber optic connector and fiber optic receptacle form two fiber optic connections when coupled together for two different optical pathways). In the illustrated embodiment, the fiber optic receptacle 234 of the bi-directional interface 232 is identical to the fiber optic receptacle 244 of the transmission and receiving interface 238. However, it is understood that the fiber optic receptacle 244 of the transmission and receiving interface 238 can be configured to couple to generally any type of fiber optic connector. Accordingly, the fiber optic receptacle 244 may have different configurations depending on the type and/or style of the fiber optic connector to which it is designed to connect (e.g., receive). For example, in some embodiments, a fiber optic receptacle may only form a single optical connection (similar to receptacle 34 of Figs. 3-9) such that transmission and receiving interface requires two fiber optic receptacles (e.g., a transmission fiber optic receptacle and a receiving fiber optic receptacle). In this embodiment, each fiber optic receptacle couples to a fiber optic connector associated with either the second or third optical waveguide. Other configurations of the transmission and receiving interface are within the scope of the present disclosure. For example, the transmission and receiving interface can comprise a fiber optic connector (e.g., a single fiber optic connector) that mechanically connects to a fiber optic receptacle to couple to the second and third optical waveguides.

[0047] In the illustrated embodiment, one or more fasteners 260 secure each fiber optic receptacle 234, 244 to its respective end fitting 252, 254.

[0048] The optical converter unit 210 includes a circulator mount 224. The circulator mount 224 holds the fiber optic circulator 222 within the tubular sleeve 250. In the illustrated embodiment, the circulator mount 224 holds two fiber optic circulators 222. In the illustrated embodiment, the circulator mount 224 generally clamps the fiber optic circulator to itself. Referring to Fig. 18, the circulator mount 224 includes a first clamp member 262 and a second clamp member 264. The fiber optic circulator 222 is clamped between the First and second clamp members 262, 264. The circulator mount 224 includes a fastener 266 (e.g., bolt) and a nut 268 threaded on the fastener for clamping the first and second clamp members 262, 264 on the fiber optic circulator 222.

[0049] The housing 214 also includes a support 270. The support 270 extends between and interconnects the first and second end fittings 252, 254. In the illustrated embodiment, the support 270 is configured to form an interference or friction fit with the first and second end fittings 252, 254 at each end of the support. The circulator mount 224 is mounted on the support 270. In the illustrated embodiment, the fastener 266 extends through the support 270 to attach the circulator mount 224 to the support. The support 270 is sized and shaped to be disposed in the interior 216.

[0050] The housing 214 includes a first retainer 272 and a second retainer 274. The first retainer 272 secures the first end fitting 252 to the tubular sleeve 250. In the illustrated embodiment, the first retainer 272 is a C-clip. The C-clip is resiliently deformable.

Accordingly, the C-clip may form a snap-fit connection. The C-clip engages the interior surface of the tubular sleeve 250 and the first end fitting 252 to secure the first end fitting to the tubular sleeve. The second retainer 274 secures the second end fitting 254 to the tubular sleeve 250. In the illustrated embodiment, the second retainer 274 is a cap. The cap threadably attaches to the tubular sleeve 250 to secure the second end fitting 254 to the tubular sleeve.

[0051] In the illustrated embodiment, the optical converter unit 210 includes two sets of optical converter components. Each set includes a fiber optic circulator 222, a bi-directional interface 232 and a transmission and receiving interface 238. In other words, the optical converter unit 210 includes two fiber optic circulators 222, two bi-directional interfaces 232 and two transmission and receiving interfaces 238. It may be preferable for the optical converter unit 210 to include two fiber optic circulators 222, two bi-directional interfaces 232 and two transmission and receiving interfaces 238 for the reasons explained herein. As mentioned above, the single fiber optic receptacle 234 forms the two bi-directional interfaces 232 of the optical converter unit 210.

[0052] Referring to Figs. 20-24, another embodiment of an optical converter unit according to the present disclosure is generally indicated by reference numeral 310. The optical converter unit 310 of Figs. 20-24 is generally analogous to the optical converter unit 210 of Figs. 14-19. Thus, for ease of comprehension, where similar, analogous or identical parts are used, reference numerals "100" units higher are employed. Accordingly, unless clearly stated or indicated otherwise, the above descriptions regarding the optical converter unit 210 of Figs. 14- 19 also apply to the optical converter unit 310 of Figs. 20-24.

[0053] In this embodiment, the transmission and receiving interface 338 of the optical converter unit 310 comprises a cable port (e.g., a first cable port). The cable port of the transmission and receiving interface 338 is configured to permit a fiber optic cable 7 to extend into the interior 316 of the housing 314. The cable port of the transmission and receiving interface 338 is also configured to mechanically connect to the fiber optic cable 7. For example, the cable port of the transmission and receiving interface 338 can include cable connection structure such as a clamp, a detent, a collar, a stop, etc. for sealingly connecting and secure the fiber optic cable 7 to the housing 314 (e.g., second end fitting 354). As explained above, the fiber optic cable 7 includes two optical pathways (broadly, the second and third optical waveguides), one of which is optically connected to the receiving port (not shown, but substantially identical to receiving port 226) of the fiber optic circulator 322 and the other of which is optically connected to the transmission port (not shown, but substantially identical to receiving port 228) of the fiber optic circulator. In other embodiments, the transmission and receiving interface may comprise two cable ports, one for each of the second and third optical waveguides.

[0054] In this embodiment, the bi-directional interface 332 of the optical converter unit 310 also comprises a cable port (e.g., a second cable port). The cable port of the bi-directional interface 332 is configured to permit a fiber optic cable 7 to extend into the interior 316 of the housing 314. The cable port of the bi-directional interface 332 is also configured to mechanically connect to the fiber optic cable 7. For example, the cable port of the bi-directional interface 332 can include cable connection structure such as a clamp, a detent, a collar, a stop, etc. for connecting and secure the fiber optic cable 7 to the housing 314 (e.g., first end fitting 352). In the illustrated embodiment, the fiber optic cable 7 includes two optical pathways (broadly, two first optical waveguides) as explained in more detail below. In other words, the cable port forms two bi-directional interfaces 232. In other configurations, the fiber optic cable attached to the bi-directional interface 332 may include more or fewer (e.g., one) optical pathways (broadly, first optical waveguides).

[0055] In the illustrated embodiment, the second retainer 374 of the housing 314 is a C- clip. The C-clip of the second retainer 374 is resiliently deformable (e.g., bendable). Accordingly, the C-clip of the second retainer 374 may form a snap-fit connection. The C-clip of the second retainer 374 engages the interior surface of the tubular sleeve 350 and the second end fitting 354 to secure the second end fitting to the tubular sleeve. [0056] In the illustrated embodiment, the optical converter unit 310 includes two sets of optical signal converter components. Each set comprises a fiber optic circulator 322, a bi directional interface 332 and a transmission and receiving interface 338. In other words, the optical converter unit 310 includes two fiber optic circulators 322, two bi-directional interfaces 332 and two transmission and receiving interfaces 338. It may be preferable for the optical converter unit 310 to include two fiber optic circulators 322, two bi-directional interfaces 332 and two transmission and receiving interfaces 338 to increase the capacity of the fiber optic system as explained herein. As mentioned above, the single cable port forms the two bi directional interfaces 332 of the optical converter unit 310. In other embodiments, each bi directional interface 332 may have its own cable port.

[0057] Modifications and variations of the disclosed embodiments are possible without departing from the scope of the invention defined in the appended claims. For example, where specific dimensions are given, it will be understood that they are exemplary only and other dimensions are possible.

[0058] When introducing elements of the present invention or the embodiment(s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0059] As various changes could be made in the above constructions, products, and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

WHAT IS CLAIMED IS:

1. An optical converter unit for converting dedicated transmission and receiving optical pathways into a single bi-directional transmission and receiving pathway, the converter unit comprising: a housing having an interior; a fiber optic circulator disposed in the interior of the housing, the fiber optic circulator having a receiving port configured to receive optical signals, a transmission port configured to transmit optical signals, and a bi-directional port configured to receive and transmit optical signals; a bi-directional interface supported by the housing, the bi-directional interface configured to mechanically couple to a first optical waveguide to optically connect the first optical waveguide to the bi-directional port of the fiber optic circulator so that optical signals are transmitted to the first optical waveguide via the bi-directional port and received from the first optical waveguide via the bi-directional port; and a transmission and receiving interface supported by the housing, the transmission and receiving interface configured to mechanically couple to a second optical waveguide to optically connect the second optical waveguide to the transmission port for transmitting optical signals from the transmission port to the second optical waveguide and to mechanically couple to a third optical waveguide to optically connect the third optical waveguide to the receiving port of the fiber optic circulator for receiving optical signals from the third optical waveguide by the receiving port of the fiber optic circulator.

2. The optical converter unit of claim 1, wherein the bi-directional interface comprises a fiber optic receptacle or a fiber optic connector configured to mechanically couple to a fiber optic connector or fiber optic receptacle, respectively.

3. The optical converter unit of claim 1, wherein the transmission and receiving interface comprises a fiber optic receptacle or a fiber optic connector configured to mechanically connect to a fiber optic connector or a fiber optic receptacle, respectively, coupled to the second optical waveguide and the third optical waveguide.

4. The optical converter unit of claim 1, wherein the transmission and receiving interface comprises a transmission fiber optic connector or a transmission fiber optic receptacle configured to mechanically connect to the second optical waveguide and a receiving fiber optic connector or a receiving fiber optic receptacle configured to mechanically connect to the third optical waveguide.

5. The optical converter unit of claim 1, further comprising a first fiber optic cable, wherein the first fiber optic cable includes the second optical waveguide and the third optical waveguide, and wherein the transmission and receiving interface comprises a first cable port configured to permit the first fiber optic cable to extend into the interior of the housing.

6. The optical converter unit of claim 5, wherein the first optical waveguide comprises a second fiber optic cable, and the bi-directional interface comprises a second cable port configured to permit the second fiber optic cable to extend into the interior of the housing.

7. The optical converter unit of claim 1, wherein the housing includes a snap-fit mount, the fiber optic circulator being mounted and held by the snap-fit mount.

8. The optical converter unit of claim 7, wherein the housing includes a base and a cover attached to the base, the base supporting the bi-directional interface and the transmission and receiving interface.

9. The optical converter unit of claim 1, wherein the housing includes a tubular sleeve with opposite first and second ends.

10. The optical converter unit of claim 9, wherein the housing includes first and second end fittings sealingly closing the first and second ends of the tubular sleeve.

11. The optical converter unit of claim 10, wherein the first end fitting supports the bi-directional interface and the second end fitting supports the transmission and receiving interface.

12. The optical converter unit of claim 11, wherein the housing includes a circulator mount holding the fiber optic circulator within the tubular sleeve.

13. The optical converter unit of claim 12, wherein the circulator mount includes a first clamp member and a second clamp member, the fiber optic circulator being clamped between the First and second clamp members.

14. The optical converter unit of claim 13, wherein the housing includes a support extending between and interconnecting the first and second end caps, the circulator mount being mounted on the support.

15. The optical converter unit of claim 14, wherein the housing includes a first retainer and a second retainer, the first retainer securing the first end fitting to the tubular sleeve and the second retainer securing the second end fitting to the tubular sleeve.

16. The optical converter unit of claim 15, wherein the first and second retainers are

C-clips.

17. The optical converter unit of claim 1, wherein the fiber optic circulator is a first fiber optic circulator, the bi-directional interface is a first bi-directional interface, and the transmission and receiving interface is a first transmission and receiving interface, the optical converter unit further comprising: a second fiber optic circulator disposed in the interior of the housing, the second fiber optic circulator having a receiving port configured to receive optical signals, a transmission port configured to transmit optical signals, and a bi-directional port configured to receive and transmit optical signals; a second bi-directional interface supported by the housing, the second bi-directional interface configured to mechanically couple to a fourth optical waveguide to optically connect the fourth optical waveguide to the bi-directional port of the second fiber optic circulator so that optical signals are transmitted to the fourth optical waveguide via the bi-directional port of the second fiber optic circulator and received from the fourth optical waveguide via the bi directional port of the second fiber optic circulator; and a second transmission and receiving interface supported by the housing, the second transmission and receiving interface configured to mechanically couple to a fifth optical waveguide to optically connect the fifth optical waveguide to the transmission port of the second fiber optic circulator so that optical signals are transmitted to the fifth optical waveguide via the transmission port of the second fiber optic circulator and to mechanically couple with a sixth optical waveguide to optically connect the sixth optical waveguide to the receiving port of the second fiber optic circulator so that optical signals are received by the receiving port of the second fiber optic circulator from the sixth optical waveguide.