LC Connector Family

The LC connector developed by Lucent Technologies and shown in Fig.3.10 is a more evolutionary approach to achieving the goals of a SFF connector. The LC connector utilizes the traditional components of a SC duplex connector having independent ceramic ferrules and housings, with the overall size scaled down by one-half. The LC family of connectors includes a stand-alone simplex design; a “behind the wall” (BTW) connector and the duplex connector available in both single-mode and multimode tolerances are all designed using the RJ-style latch.

The outward appearance and physical size of the LC connector varies slightly depending on the application and vendor preference. Although all the connectors in the LC family have similar latch styles modeled after the copper RJ latch, the simplex version of the connector has a slightly longer body than either the duplex or BTW version, and the latch has an additional latch actuator arm that is designed to assist in plugging as well to prevent snagging in the field. The BTW connector is the smallest of the LC family and is designed as a field-or board-mounatable connector using 900-um buffered fiber and in some cases has slightly extended latch for extraction purposes. The duplex version of this connector has modified body to accept the duplexing clip that joins the two connector bodies toghther and actuates the two latches as one. Finally, even the duplex clip itself has variations depending on the vendor. In some cases the duplex clip us a solid one-piece design and must be placed on the cable prior to connectorization, while other design and must be placed on the cable prior to connectorization, while other designs have slots built into each side to allow the clip to be installed after connectorzation. In coclusion, all LC connectors are not created equal, and depending on style and manufacturer’s preference, there may be attributes that make one connector more suitable for a specific application then another.

The LC duplex connector incorporates two round ceramic ferrules with outer diameters of 1.25mm and a duplex pitch of 6.25mm. These ferrules are aligned through the traditional couplers and bores using precision ceramic split or solid sleeves. In an attempt to improve the optical performance to better than 0.10 db at these interfaces, most of the ferrule and backbane assemblies are designed to allow the cable manufacturer to tune them. Tuning of the LC connector simply consists of roating the ferrule to one of four available positions dictated by the backbone design. The concept is basically to align the concentricity offset of each ferrule to a single quadrant at 12.00; in effect, if all the cores are slightly offset in the same direction, the probalility of a core-to-core alignment is increased and optimum performance can be achieved. Although this concept has its merits, it is yet another costly step in the manufacturing process, and in the case where a tuned connector is mated with an untuned connector, the increase in performance may not be realized.

Typically, the LC duplex connectors are terminated onto a new reduced-size zipcord referred to as mini-zip. However, as the product matures and the applications expand, it may be found on a number of different cordages. The mini-zip cord is one of the smallest in the industry with an outer diameter of 1.6mm compared with the standard zipcord for an SC style product of 3.0 mm. Although this cable has passed industry standard testing, the cable manufacturers have raised some issues concering the ability of the 900-um fibers to move freely inside a 1.6-mm jacket and others involving the overall crimped pull strengths. For these reasons, some end users and calbe manufactures are opting for a larger 2.0-mm, 2.4-mm, or even the standard 3.0-mm zipcord. In application wher the fiber is either protected within a wall outlet or cabinet, the BTW connector is used and terminated directly onto the 900-um buffers with no jacket protection.

The factory termination of the LC cable assemblies is very similar to order ceramic-based ferrules using the standard pot and polish processes with a few minor differences. The one-piece design of the connector minimizes production handling and helps to increase process yields when compared with other SFF and standard connector types. Because of the smaller diameter ferrule, the polishing times for an LC ferrule may be slightly lower than the standard 2.5-mm connectors, but the real production advantage is realized in teh increase number of connectors that can be polished at one time in a mass polisher. For the reasons mentioned above and because the process is familiar to most manufacturers, the LC connector may be considered one of the eaisest SFF connectors to factory terminate.

Field termination of the LC connector has typically been accomplished through the standard pot and polish techiques using the BTW connector. However, a pre-polished, crimp and cleave connector is also available. The LCQuick Light field-mountable BTW style connector made by Lucent Technologies is a one-piece design with a factory polished ferrule and an internal cleaved fiber stub. Unlike other pre-polished SFF connectors previously discussed, the LCQuick light secures the inserted field cleaved fiber to a factory polished stub by crimping or collapsing the metallic entry tube onto the buffered portion. This is accomplished by using a special crimp tool that is designed not to damage the fibers. However, light is designed specifically for use in protected environments such as cabinets and wall outlets and has no provision for outer jacket or Kevlar protection.

LC connections allow higher density applications based on its smaller diameter. The LC connection, commonly referred to as Lucent Connection, Little Connector or Local Connector, is commonly used today for uplink modules and other devices. This connector is a “snap” type, has a ferrule diameter of 1.25mm and defined by IEC 61754-20. We offer LC fiber cables and lc lc cable, including single mode 9/125 and multimode 50/125, multimode 62.5/125, LC-LC, LC-SC, LC-ST, LC-MU, LC-MTRJ, LC-MPO, LC-MTP, LC-FC, OM1, OM2, OM3. Other types also available for custom design. Excellent quality and fast delivery.

The LC fiber patch cable cable is with a small form factor (SFF) connector and is ideal for high density applications. The LC fiber patch connector has a zirconia ceramic ferrule measuring 1.25mm O.D. with either a PC or APC end face, and provides optimum insertion and return loss. The LC fiber patch cable connector is used on small diameter mini-cordage (1.6mm/2.0mm) as well as 3.0mm cable. LC fiber cable connectors are available in cable assembled or one piece connectors. The LC fiber optic assemblies family is Telcordia, ANSI/EIA/TIA and IEC compliant.

Three Types of Cable Connectors Used in Cabling Installation Techniques

There are three types cable connectors in a basic cabling installation techniques: twisted-pair connectors,coaxial cable connectors and fiber-optic connectors. Generally cable connectors have a male component and a female component, except in the case of hermaphroditic connectors such as the IBM data connector. Usually jacks and plugs are symmetrically shaped, but sometimes they are keyed. This means that they have a unique, asymmetric shape or some system of pins, tabs, and slots that ensure that the plug can be inserted only one way in the jack.

Twisted-Pair Cable Connectors

Many people in the cabling business use twisted-pair connectors more than any other type of connector. The connectors include the modular RJ types of jacks and plugs and the hermaphroditic connector employed by IBM that is used with shielded twisted-pair cabling. Twisted-Pair Cable Connectors are used with patch panels, punchdown blocks, and wall plates. Twisted-Pair Cable connector is called an IDC, or insulation displacement connector.

Most unshielded twisted-pair (UTP) and screened twisted-pair (ScTP) cable installations use patch panels and, consequently, 110-style termination blocks. The 110-Block contains rows of specially designed slots in which the cables are terminated using a punch-down tool. When terminating 66-blocks, 110-blocks, and often, wall plates, both UTP and ScTP connectors use IDC technology to establish contact with the copper conductors. You don’t strip the wire insulation off the conductor as you would with a screw-down connection. Instead, you force the conductor either between facing blades or onto points that pierce the plastic insulation and make contact with the conductor.

Both UTP and ScTP cables use modular jacks and plugs. For decades, modular jacks have been commonplace in the home for telephone wiring. Modular connectors come in four-, six-, and eight-position configurations. The number of positions defines the width of the connector. However, often only some of the positions have metal contacts installed. Make sure that the connectors you purchase are properly populated with contacts for your application.

Common Modular-Jack Designations and Their Configuration
Coaxial Cable Connectors

Unless you have operated a 10Base-2 or 10Base-5 Ethernet network, you are probably familiar only with the coaxial connectors you have in your home for use with televisions and video equipment. Actually, a number of different types of coaxial connectors exist.

The coax connectors used with video equipment are referred to as F-series connectors.The F-connector consists of a ferrule that fits over the outer jacket of the cable and is crimped in place. The center conductor is allowed to project from the connector and forms the business end of the plug. A threaded collar on the plug screws down on the jack, forming a solid connection. F-connectors are used primarily in residential installations for RG-58, RG-59, and RG-6 coaxial cables to provide CATV, security-camera, and other video services.

F-Series Coaxial Connectors

F-connectors are commonly available in one-piece and two-piece designs. In the two-piece design, the ferrule that fits over the cable jacket is a separate sleeve that you slide on before you insert the collar portion on the cable. Experience has shown us that the single-piece design is superior. Fewer parts usually means less fumbling, and the final crimped connection is both more aesthetically pleasing and more durable. However, the usability and aesthetics are largely a function of the design and brand of the two-piece product. Some two-piece designs are very well received by the CATV industry.

N-Series Coaxial Connectors

The N-connector is very similar to the F-connector but has the addition of a pin that fits over the center conductor; The pin is suitable for insertion in
the jack and must be used if the center conductor is stranded instead of solid. The assembly is attached to the cable by crimping it in place. A screw-on collar ensures a reliable connection with the jack. The N-type connector is used with RG-8, RJ-11U, and thicknet cables for data and video backbone applications.

The BNC Connector

When coaxial cable distributes data in commercial environments, the BNC connector is often used. BNC stands for Bayonet Neill-Concelman, which describes both the method of securing the connection and its inventors. Many other expansions of this acronym exist, including British Naval Connector, Bayonet Nut Coupling, Bayonet Navy Connector, and so forth. Used with RG-6, RG-58A/U thinnet, RG-59, and RG-62 coax, the BNC utilizes a center pin, as in the N-connector, to accommodate the stranded center conductors usually found in data coax.

The BNC connector comes as a crimp-on or a design that screws onto the coax jacket. As with the F-connector, the screw-on type is not considered reliable and should not be used. The rigid pin that goes over the center conductor may require crimping or soldering in place. The rest of the connector assembly is applied much like an F-connector, using a crimping die made specifically for a BNC connector.

Fiber-Optic Cable Connectors

Fiber-optic connections use different terminology than copper based connectors. The male end of the connection in a fiber-optic system is termed the connector, in contrast to the plug in a copperbased system. The female end of the connection is termed the receptacle or adapter, in contrast to the jack in a copper-based system.

To transmit data up to 10Gbps, two fibers are typically required: one to send and the other to receive. For 40Gbps and 100Gbps over multimode, as many as 24 fibers will be required. Fiber optic connectors fall into one of three categories based on how the fiber is terminated:

  • Simplex connectors terminate only a single fiber in the connector assembly.
  • Duplex connectors terminate two fibers in the connector assembly.
  • Array connectors terminate more than two fibers (typically 12 or 24 fibers) in the connector assembly.

The disadvantage of simplex connectors is that you have to keep careful track of polarity. In other words, you must always make sure that the connector on the “send” fiber is always connected to the “send” receptacle (or adapter) and that the “receive” connector is always connected to the “receive” receptacle (or adapter). The real issue is when normal working folk need to move furniture around and disconnect from the receptacle in their work area and then get their connectors mixed up. Experience has shown us that the connectors are not always color coded or labeled properly. Getting them reversed means, at the least, that link of the network won’t work.

Array and duplex connectors and adapters take care of this issue. Once terminated, color coding and keying ensures that the connector can be inserted only one way in the adapter and will always achieve correct polarity.

The SFF Connector

As transmission rates increase and networks require the cramming in of a greater number of connections, the industry has developed small-form-factor (SFF) connectors and adapter systems for fiber-optic cables. The SC, ST, and FC Connectors shown in Table 10.5 all take up more physical space than their RJ-45 counterparts on the copper side. This makes multimedia receptacle faceplates a little crowded and means that you get fewer terminations (lower density) in closets and equipment rooms than you can get with copper in the same space. The goal for the designers of the SFF connector was to create an optical-fiber connector with the same or lower crosssectional footprint as an RJ-45-style connector in order to increase the number of connections per area (higher density). The LC, the VF-45, and the MT-RJ SFF fiber-optic connectors were initially developed to support the increase in density of fiber connections. The LC Connectoris gaining greater use and is regarded by many optical-fiber professionals.

Several Common Types Of Fiber Optic Cables And Patch Cables

1.FTTH Fiber Cable

FTTH (Fiber To The Home), as its name suggests it is a fiber optic directly to the home. Specifically, FTTH refers to the optical network unit (ONU) mounted on home users or business users, is the optical access network application type of closest to users in optical access series except FTTD(fiber to the desktop).

There are 5 main advantages of FTTH:
First, it is a passive network, from the end to the user, the intermediate can be basically passive;
Second, the bandwidth is relatively wide, long distance fits the massive use of operators;
Third, because it is carried business in the fiber, and there is no problem;
Fourth, because of its relatively wide bandwidth, supported protocol is more flexible;
Fifth, with the development of technology, including point-to-point, 1.25G and FTTH have established relatively perfect function.

2. Indoor Fiber Optic Cable

Indoor optical cable is classified according to the using environment, as opposed to outdoor fiber optic cable.

Indoor optical cable is a cable composed of fiber optic (optical transmission medium) after a certain process. Mainly by the optical fiber (glass fiber is as thin as hair),plastic protective tube and plastic sheath. There is no gold, silver, copper and aluminum and other metal, fiber optic cable generally has no recycling value.

Indoor fiber optic cable is a certain amount of fiber optic forming to cable core according to a certain way, outsourcing jacket, and some also coated layer of protection, to achieve a communication line of light signal transmission.

Indoor cable is small tensile strength, poor protective layer, but also more convenient and cheaper. Indoor cable mainly used in building wiring, and connections between network devices.

3. Outdoor Fiber Optic Cable

Outdoor fiber optic cable, used for outdoor environment, the opposite of indoor fiber optic cable.

Outdoor cable is a type of communication line to achieve light signal transmission, is composed of a certain amount of fiber optic forming to cable core according to a certain way, outsourcing jacket, and some also coated with outer protective layer.

Outdoor cable is mainly consists of optical fiber (glass fiber is as thin as hair), plastic protection tube and plastic sheath. There is no gold, silver, copper and aluminum and other metal cable, generally no recycling value.

Outdoor cable is greater tensile strength, thick protective layer, and usually armored(wrapped in metal). Outdoor cables are mainly applied to buildings, and remote networks interconnection.

4.Fiber Optic Patch Cable

Fiber optic patch cable, also known as fiber jumper, used to connect from the device to fiber optic cabling link. Fiber jumper has a thick protective layer, generally used in the connection between the fiber converter and Fiber Termination Box. Commonly used fiber jumpers include: ST, LC, FC and SC.

Main Categories
Single-mode fiber patch cable: General single-mode fiber jumper is colored in yellow, connector and protective sleeve are blue; long transmission distance.

Multi-mode fiber patch cable: General multimode fiber jumper is colored in orange and some in gray, connector and protective sleeve are beige or black and the transmission distance is short.

Fiber optic jumper connector interpretation:
SC Connector: square fiber optical connector;
FC Connector: round with thread;
ST Connector: similar to BNC;
LC Connector: transceiver separation structure;
MT-RJ Connector: square, one with double fiber;
PC Connector: direct contact;
APC Connector:8 degree tilt angle of contact surface;
UPC Connector: arc contact surface.