Patent Application
20240219647
The mechanical tolerances involved in terminating single mode optical fiber are much tighter than those for multimode optical fiber. Therefore, while it is quite common for multimode optical fiber to be terminated at the point of use, for example, at a user's premises or at an outside junction box, in most product applications, single mode optical fiber is not terminated in the field. When single mode fiber must be terminated in the field, it can take a skilled technician between about 15 to 20 minutes to splice fibers together either by using a V-groove clamp or expensive fusion welding equipment.
Single mode fiber is therefore often provided in a range of different lengths, pre-terminated at both ends with a connector plug ready to plug into a matching receptacle. Commonly, eight or twelve single mode optical fibers may be bundled together in an optical fiber cable having an outer protective tube inside of which the optical fibers run.
An example of such a connector is the “Subscriber Connector,” or SC connector, originally developed by NTT®. SC connectors have convenient push/pull style mating and are approximately square in cross-section and with a 2.5 mm diameter ferule at the termination of the optical fiber, surrounded by a plastic housing for protection. SC connectors are available in single or duplex configurations. The SC connector latches into a matching socket in a simple push motion. The push-pull design includes a spring against which the ferrule slides within a plastic inner housing. This arrangement provides a reliable contact pressure at the ferrule end and resists fiber end face contact damage of the optical fiber during connection. The connector can be quickly disconnected by disengaging a latch, before pulling the optical fiber connector from the socket. Until the latch is thus disengaged, the latch prevents withdrawal of the connector when the optical fiber cable is pulled in a direction away from the socket.
Other examples of push/pull type connectors are LC connectors (Lucent Connectors) or MU connectors. Often, the end face of the ferrule is angled to reduce back reflections and this is usually described by adding APC (Angled Physical Contact) to the name. All such push/pull type optical fiber connectors are for convenience referred to herein as “SC-type” optical fiber connectors. SC-type LC or MU connectors are also known as small form factor connectors, by virtue of having a 1.5 mm diameter ferrule and a plastic housing.
Signal losses within a system often occur within the connection between two optical fiber cores. For example, when the fiber is inserted into the ferrule, the core of a fiber may not and typically does not end up perfectly centered relative to the ferrule outer diameter due to manufacturing tolerances of the ferrule outer diameter to inner diameter concentricity, ferrule inner diameter hole size, fiber outer diameter, and fiber core to fiber outer diameter concentricity. If one or both of the fibers of mating connectors are off center when they are connected within an adapter, the fibers will not be aligned and thus there will be a signal loss when the signal is transmitted between the two fibers. It is therefore desirable to tune a connector to minimize this signal loss. Tuning can be accomplished by measuring signal characteristics through the connector and/or examining physical properties of the connector and then determining the optimal position of the ferrule and fiber in the connector.
It may be desirable to provide an optical fiber connector having a tuned ferrule that can float when the ferrule engages with a mating ferrule in order to minimize transmission losses.
In accordance with an exemplary embodiment of the disclosure, an optical fiber connector subassembly configured to reduce signal transmission losses in an optical fiber connector may include a ferrule assembly having a ferrule and a holding portion structurally configured to fixedly hold the ferrule, a receiving portion configured to be rotationally fixed to a fiber cable, and a biasing portion configured to be disposed between the holding portion and the receiving portion. The receiving portion may include a first receiving portion and a second receiving portion, and the holding portion may include a tuning portion. The second receiving portion may include a tuning portion receiving portion structurally configured to receive the tuning portion such that the holding portion is rotationally fixed with the second receiving portion, and the biasing portion may be structurally configured to bias the ferrule assembly toward a front abutment surface portion of the first receiving portion along a connector axis. The tuning portion receiving portion may include a hexagonal bore portion, and the tuning portion may include a hexagonal outer surface portion configured to be received by the hexagonal bore portion in any one of six relative rotational positions between the tuning portion and the tuning portion receiving portion. The holding portion is configured to be moved toward the biasing portion so as to compress the biasing portion and remove the tuning portion from the tuning portion receiving portion such that the holding portion is configured to be rotated relative to the second receiving portion so as to arrange the hexagonal outer surface portion and the hexagonal bore portion in one of the six relative rotational positions between the tuning portion and the tuning portion receiving portion that optimizes eccentricity of the ferrule and a fiber terminated by the ferrule relative to the tuning portion receiving portion so as to minimize signal transmission loss when the ferrule abuts a mating ferrule.
In some embodiments of the optical fiber connector subassembly, a rear end of the biasing portion may be configured to abut a forward facing surface of the hexagonal bore portion. In some aspects, a front end of the biasing portion may be configured to abut a rearward facing surface of the holding portion.
In some embodiments of the optical fiber connector subassembly, the holding portion may include a forward end portion and an extension portion extending from the forward end portion and configured to extend through the biasing portion.
In some embodiments, an optical fiber connector for achieving reduced signal transmission losses between mating ferrules may include an embodiment of the optical fiber connector subassembly and a housing portion configured to receive the connector subassembly.
In some embodiments, the optical fiber connector may include an outer housing portion configured to receive the housing portion and the connector subassembly. In some aspects, the connector may comprise a subscriber (SC) connector.
In accordance with an exemplary embodiment of the disclosure, optical fiber connector subassembly configured to reduce signal transmission losses in an optical fiber connector may include a tuning portion fixedly coupled with a ferrule, a receiving portion configured to be slidingly moved relative to the tuning portion along an axis, and a biasing portion configured to be disposed between the tuning portion and the receiving portion. The receiving portion may be structurally configured to receive the tuning portion such that the tuning portion is rotationally fixed with the receiving portion, the receiving portion may include a polygonal bore portion having N sides, and the tuning portion may include a polygonal outer surface portion configured to be received by the polygonal bore portion in any one of N relative rotational positions between the tuning portion and the receiving portion. The tuning portion may be configured to be slidingly moved so as to compress the biasing portion and remove the tuning portion from the receiving portion such that the tuning portion is configured to be rotated relative to the receiving portion so as to arrange the polygonal outer surface portion and the polygonal bore portion in one of the N relative rotational positions between the tuning portion and the receiving portion that optimizes eccentricity of the ferrule and a fiber terminated by the ferrule relative to the tuning portion receiving portion so as to minimize signal transmission loss when the ferrule abuts a mating ferrule.
In some embodiments of the optical fiber connector subassembly, a rear end of the biasing portion may be configured to abut a forward facing surface portion of the polygonal bore portion. In some aspect, a front end of the biasing portion may be configured to abut a rearward facing surface portion of the tuning portion.
In some embodiments of the optical fiber connector subassembly, the tuning portion may include a holding portion structurally configured to hold a ferrule and an extension portion extending from the holding portion to the polygonal outer surface portion. In some aspects, the extension portion may be configured to extend through the biasing portion.
In some embodiments of the optical fiber connector subassembly, the polygonal outer surface portion may comprise a hexagonal outer surface portion, and the polygonal bore portion may comprise a hexagonal bore portion.
In some embodiments of the optical fiber connector subassembly, the biasing portion may be structurally configured to bias the tuning portion toward a front abutment surface portion of the receiving portion.
In some embodiments, an optical fiber connector for achieving reduced signal transmission losses between mating ferrules may include an embodiment of the optical fiber connector subassembly and a housing portion configured to receive the connector subassembly.
In some embodiments, the optical fiber connector may include an outer housing portion configured to receive the housing portion and the connector subassembly. In some aspects, the connector may comprise a subscriber (SC) connector.
In accordance with an exemplary embodiment of the disclosure, an optical fiber connector subassembly configured to reduce signal transmission losses in an optical fiber connector may include a tuning portion coupled with a ferrule and a receiving portion configured to be slidingly moved relative to the tuning portion. The receiving portion may be structurally configured to receive the tuning portion such that the tuning portion is rotationally fixed with the receiving portion. The receiving portion may comprise a bore having a number N of sides, and the tuning portion may comprise an outer surface having N sides configured to be received by the bore in any one of N relative rotational positions between the tuning portion and the receiving portion. The tuning portion may be configured to be rotated relative to the receiving portion so as to arrange the polygonal outer surface and the polygonal bore in one of the N relative rotational positions between the tuning portion and the receiving portion so as to minimize signal transmission loss when the ferrule abuts a mating ferrule.
In some embodiments, the optical fiber subassembly may include a biasing portion configured to be disposed between the tuning portion and the receiving portion.
In some embodiments of the optical fiber connector subassembly, a rear end of the biasing portion may be configured to abut a forward facing surface portion of the polygonal bore portion. In some aspects, a front end of the biasing portion is configured to abut a rearward facing surface portion of the tuning portion.
In some embodiments of the optical fiber connector subassembly, the tuning portion may comprise a holding portion structurally configured to hold a ferrule and an extension portion extending from the holding portion to the polygonal outer surface portion. In some aspects, the extension portion may be configured to extend through the biasing portion.
In some embodiments of the optical fiber connector subassembly, the biasing portion may be structurally configured to bias the tuning portion toward a front abutment surface portion of the receiving portion.
In some embodiments of the optical fiber connector subassembly, the tuning portion may be configured to be slidingly moved so as to compress the biasing portion and remove the tuning portion from the receiving portion such that the tuning portion is configured to be rotated relative to the receiving portion.
In some embodiments of the optical fiber connector subassembly, the outer surface portion may comprise a hexagonal outer surface portion, and the bore portion may comprise a hexagonal bore portion.
In some embodiments, an optical fiber connector for achieving reduced signal transmission losses between mating ferrules may include an embodiment of the optical fiber connector subassembly and a housing portion configured to receive the connector subassembly.
In some embodiments, the optical fiber connector may include an outer housing portion configured to receive the housing portion and the connector subassembly. In some aspects, the connector may comprise a subscriber (SC) connector.
Further advantages and features of the present disclosure will become apparent from the following description and the accompanying drawings, to which reference is made.
Reference will now be made in detail to exemplary embodiments and methods of the present disclosure, which constitute the best modes of practicing the present disclosure presently known to the inventors. It is to be understood that the disclosed embodiments are merely exemplary of the present disclosure that may be embodied in various and alternative forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for any aspect of the present disclosure and/or as a representative basis for teaching one skilled in the art to variously employ the present disclosure.
It must also be noted that, as used in the specification and the appended claims, the singular form “a,” “an,” and “the” comprise plural referents unless the context clearly indicates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components.
With reference to
As shown in
The first and second receiving portions 120, 140 are configured to cooperate to form a retaining portion 118, for example, a ferrule holder carrier. The fiber optic connector subassembly 110 further includes a ferrule 108 and a holding portion 112, for example, a ferrule holder. The retaining portion 118 is configured to hold and retain the holding portion 112 therein. For example, a first or forward end 124 of the first receiving portion 120 includes a tapered inner surface 1241, and a first or forward end 1121 of the holding portion 112 includes a tapered outer surface 1121. A diameter of a largest end the tapered outer surface 1121 is greater than a diameter of a smallest end of the tapered inner surface 1241 such that the holding portion 112 is prevented from passing through the tapered inner surface 1241 at the first end 124 of the first receiving portion 120.
The first end portion 1121 of the holding portion 112 is configured to receive and hold the ferrule 108 such that the ferrule 108 extends from the first end portion 1121 and extends through the tapered inner surface 1241 at the first end portion 124 of the first receiving portion 120 and out of the retaining portion 108 via an opening 1242 at the first end 124.
The holding portion 112 includes a second end portion 126 comprising, for example, a stem portion 1261 and a flange portion 1262 at a free end 1263 of the second end portion 126. A transition from the first end portion 124 to the second end portion 126 may comprise a stepped transition from the wider first end portion 124 to the narrower stem portion 1261 that defines an engagement portion 1264, for example, a rearward facing surface portion.
As best illustrated in
In an exemplary embodiment, the flange portion 1262 comprises a periphery 1265 having six flattened sides 1266. It should be appreciated that, in other embodiments, the flange portion 1262 may have a periphery that includes three sides, four sides, five sides, or more than six sides.
The inner surface 1443 of the flange portion 144 of the second receiving portion 140 includes a broached profile 1444 that is complementary to the shape of the periphery of the flange portion 1262. For example, as illustrated, the periphery 1265 of the flange portion 1262 has six flattened sides 1264, and the inner surface 1443 of the flange portion 144 comprises a broached hexagonal profile that has six sides sized and configured to receive the flange portion 1262.
The number of sides 1264 of the periphery 1265 of the flange portion 1262 and the corresponding number of sides of the broached profile 1444 of the inner surface 1443 of the flange portion 144 determines a number of predetermined tuning positions of the ferrule 108, as will be discussed below. Each of the predetermined tuning positions defines a potential tuning orientation of the ferrule 108 relative to the retaining portion 118 about an axis wherein the ferrule 108 is tuned or optimized. Tuning refers to optimizing fiber core eccentricity by rotating the ferrule 108 in the retaining portion 118 to provide better alignment between mating fibers whose connectors have been tuned.
Referring to
Referring now to
It should be appreciated that a connector subassembly 110 having six predetermined tuning positions permits the ferrule 108 and fiber 154 to be positioned within 30° of the best possible fiber core eccentricity, thereby optimizing alignment between mating fibers whose connectors have also been tuned. Having more predetermined tuning positions would position the ferrule 108 and fiber 154 closer to the best possible fiber core eccentricity, and the opposite would be true if fewer predetermined tuning positions were provided.
It should be understood that, in some aspects, the arrangement of the first receiving portion 120, the second receiving portion 140, the biasing member 114, the holding portion 112, and the ferrule 108 is configured to enable the holding portion 112 and the ferrule 108 to float wherein the angled end face 1081 of the ferrule 108 has the flexibility to move together with mating ferrule when a load is applied to a rear portion of the connector 100 to maintain a connection between their end faces. As a result of the maintained connection between the end faces, the risk of disruption to a signal between the ferrules is significantly reduced. The ferrule 108 and holding portion 112 may also freely move backwards when an end face 1081 of the ferrule 108 comes into contact with a similar end face of another optical fiber ferrule when making an optical connection given that the biasing member 114 may be compressed as the ferrule 108 and holding portion 112 move toward the second receiving portion 140 upon contact with a mating ferrule. Thus, when the holding portion 112 moves toward the second receiving portion 140, the holding portion 112 may no longer contact the abutment surface of the first receiving portion, as described above.
While multiple example, non-limiting embodiments have been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.
This application claims the benefit of U.S. Provisional Application No. 63/436,516, filed Dec. 31, 2022, pending, the disclosure of which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63436516 | Dec 2022 | US |
