Understanding Fiber Optic Cables

Fiber optic cable is an updated, faster way to transfer data. They use light (laser) instead of electricity to send data signals. For higher bandwidths, optical signals can travel faster, with less signal loss and less electronic interference. There are several different types of fiber optic cables, with multiple types of cables and multiple connectors.

Cable types include:

  • Single mode
  • Multimode
    • OM1
    • OM2
    • OM3
    • OM4

Connector types include:

  • FC
  • LC
  • SC
  • ST
  • MTP / MPO
  • MTRJ

Optic fiber cable

Single mode

Single mode fiber contains a very thin core, making it ideal for remote transmission. These cables can be very long and a line can run for miles. The single mode cable transmits light between 1,300 and 1,550 μm, which makes it almost infrared. This version of fiber optic cable is primarily used for telecommunications.

The name “single mode” comes from the cable and only transmits light in a single mode along the cable. Typically, single-mode fibers are yellow. The disadvantage of single modes is that their long-distance means they need a very powerful laser to work at these extreme distances. The equipment needed to make a powerful laser is often very expensive.


Multimode fiber has a thicker core than a single die, and the exact thickness depends on the multimode you are referring to. A thicker core allows multiple optical signals to bounce through the cable, which provides better signal speed. These are the types of fiber you typically see in buildings and are usually rated as less than one kilometer. If you are not sure whether to use a single-mode or multimode cable, you can usually judge by the color of the cable and write it on the cable jacket.


The OM1 is usually orange and has a rated stroke of up to 300 meters. They maintain a 1GB transfer rate and are most commonly used in computer networks within buildings.


OM2 shares its color with OM1 but covers twice as long as 600 meters. Beyond the larger distance limit, its specifications match the OM1. OM2 is used in areas where 1GB speed is satisfactory but requires a greater distance.


The OM3 is light green with speeds up to 10GB and up to 300 meters. At shorter distances, you can get better speed from OM3. With MPO connectors, distances of up to 100 meters can reach 40 or even 100 GB. OM3 provides a speed upgrade for OM1, making it ideal for networks that receive large amounts of traffic.


OM4 is a remote upgrade of OM3 (similar to the way OM1 is upgraded from OM1). The OM4 can carry up to 10GB of signal up to 550 meters and 100GB of signal up to 150 meters (the latter still uses MPO connectors). These are typically used for large facilities with high-speed networks, such as data centers and financial institutions.

The optical fiber connector

Fiber optic cables have a significant number of different connectors. Each connector has a simplex and duplex version. Simplex will have a single connector, and dual tools have a pair. Fiber optic signals are unidirectional; use duplex connectors when you need to send signals back and forth instead of just one direction.

FC Connector

FC (Ring Core Connector) is an older fiber optic connector that began to phase out. It is a threaded, threaded connector that requires more time to plug in and out than the new fiber optic connector. In addition, FC connectors are more expensive to manufacture than new connectors while providing the same level of signal quality. The advantage of maintaining the FC market is that their threads allow them to remain in place during motion, such as moving or vibrating machinery.

LC Connector

The LC (Lucent Connector) fiber is a push-pull design with a latch to hold itself in place. The biggest advantage of LC is its small size, which is about half that of other fiber connections. This small form factor allows the device with no space on the fiber port to use LC.

SC Connector

SC connector (standard connector) is a common variant of fiber optic connectors. Simple and inexpensive, the SC also uses a push-pull system, but with a locking tab instead of a latch like LC. This cost-effectiveness makes SC very popular among telecommunications companies, although it can also be used for data communication applications.

ST Connector

The ST connector is similar in appearance to FC, but it uses a locking mechanism similar to a BNC coaxial connector instead of a thread. Like FC, it has also begun to phase out, mainly because it can only be used for single-mode cables. As multiple modes become more popular and better implemented, more ST connectors will continue to be replaced by LC and SC.

MTP / MPO Connector

Multi-fiber connectors (MTP and MPO) are larger than other fiber connectors but can support up to 24 fibers with one hand. These cables are used in systems that use many connections, such as data centers. MTP / MPO difficult to manufacture, and they are not re-adjusted after the optical fiber cable termination, the cable thus usually on one side of an MTP / MPO, and branches to other types of connections, such as the LC.

MTRJ Connector

The MTRJ (Mechanical Transmission Registered Jack) is a new small connector that is the size of a telephone jack. Their small size allows for two ports, where something like SC duplex takes up a point, doubling the connection you can include. Although still too new to be widely used, it is an up-and-coming connector that may become the new standard for the future.

Some versions of fiber optic cable are divided into UPC  or APC. For example, the UPC rated SC cable will be labeled SC-UPC. UPC (Super Physical Contact) uses polishing technology to reduce signal loss compared to standard fiber optic connectors. The downside is that they get worse quickly, especially when cables are plugged and unplugged frequently. APC (inclined physical contact) corrects the problem of UPC by making the connector at an 8° angle. This tilted position allows for a tighter, safer fit, but if the connector is inverted or inserted sideways, it can cause rotation problems.

Original Article Source from https://www.showmecables.com/blog/post/fiber-optic-cables/