Computer and Software Support


Fiber connectors

This information is from CablesToGo pasted here to avoid broken links. If you would like to read it from their site, click here.

Fiber transmits signal via light instead of by electrical signals. There is two types of fiber. There is fiber that uses LED to transmit signal, and the other is laser.

Word of caution, never look directly at the light. The light can harm your eyes.

There is three major components of a fiber connector

  1. Ferrule - This is a thin structure that is often cylindrical. The purpose of the Ferrule is to hold the glass fiber. The center is hallowed-out that forms a tight grip on the fiber. They are usually made from ceramic, metal, or high-quality plastic, and typically will hold one strand of fiber
  2. Connector body - This holds the ferrule and attaches to the jacket and strength members of the fiber. It is either plastic, or a metal structure.
  3. Coupling mechanism - This is a part of the connector body that holds the connector in place when it gets attached to another device (a switch, NIC, bulkhead coupler, etc.). It may be a latch clip, a bayonet-style nut, or similar device.
   

 

Below is a list of different connectors (This is not a full list)

  1. ST Connector - The ST connector was one of the first connector types widely implemented in fiber optic networking applications. Originally developed by AT&T, it stands for Straight Tip connector. ST connections use a 2.5mm ferrule with a round plastic or metal body. The connector stays in place with a “twist-on/twist-off” bayonet-style mechanism. Although extremely popular for many years, the ST connector is slowly being supplanted by smaller, denser connections in many installations. For instructions on how to connect the fiber to the connector, click here

   
  1. SC Connector - SC connectors also use a round 2.5mm ferrule to hold a single fiber. They use a push-on/pull-off mating mechanism which is generally easier to use than the twist-style ST connector when in tight spaces. The connector body of an SC connector is squarish, and two SC connectors are usually held together with a plastic clip (this is referred to as a duplex connection). The SC connector was developed in Japan by NTT (the Japanese telecommunications company), and is believed to be an abbreviation for Subscriber Connector, or possibly Standard Connector.

   
  1. LC - One popular SFF connector is the LC type. This interface was developed by Lucent Technologies (hence, Lucent Connector). It uses a push-pull mechanism, similar to the SC, and the connector body resembles the squarish shape of SC connectors as well. LC connectors are normally held together in a duplex configuration with a plastic clip. The ferrule of an LC connector is 1.25mm.

   
  1. FC Connector - A slotted screw-on type connector. This connector is popular in singlemode applications.

   
  1. SMA Connector - A screw-on type connector. This connector is decreasing in popularity.

   
  1. FDDI Connector - FDDI stands for Fiber Distributed Data Interface, and it actually refers to a local area network standard such as Ethernet or Token Ring. The termination on the fiber optic cable itself is called an FDDI connector, or is also known as an MIC (Media Interface Connector) connector. It contains two ferrules in a large, bulky plastic housing that uses a squeeze-tab retention mechanism.

   
  1. Mini-BNC Connector - A bayonet style connector using the traditional BNC connection method.

   
  1. Biconic Connector - A screw-on style connector. This connector is almost obsolete.

   
  1. MT-RJ Connector - This is another popular SFF connector. Based on a specification by NTT, it was developed by AMP/Tyco and Corning, and stands for Mechanical Transfer-Registered Jack. The MT-RJ connector closely resembles an RJ-style modular plug, even getting part of its name from the resemblance. MT-RJ connectors are always duplex in that they hold two fibers. The body and ferrule are normally made from plastic or plastic composite, and lock into place with a tab (just like a modular RJ-style plug).

   
  1. ST Feedthru - A slotted bayonet type feedthru. ST connectors are one of the most popular styles.

   
  1. SC Feedthru - A push/pull type feedthru. FDDI connector are popular in both singlemode and multimode applications

   
  1. FC Feedthrou - A slotted screw-on type feedthru. FC connectors are popular in singlemode applications.

  2. Small Form Factor Connectors (SFF) - SFF connectors grew from the effort to make fiber connections smaller. In a rack or closet environment, space for several connections is limited, and thus manufacturers sought a way to increase port density. A standard was developed for smaller connectors called SFF (Small Form Factor). There are many different types of SFF connectors, but they are all smaller than normal ST or SC connections.

 

 




There are some other SFF connectors in the marketplace, which are not widely popular as the LC and MT-RJ. These include the Volition VF-45 by 3M, the Opti-Jack by Panduit, the SC-DC, and the MU.

 

If you want to know the distances, different cables can reach, click here

For more information or help, check these pages out