http://www.precisionfiberproducts.com/connectors/ There are several types of fiber optic connectors used in industry today. Precision Fiber Products offers this guide to help in identifying and selecting fiber optic connectors by their shape and function.

1. Different Types of Fiber Optic Connectors and Their Uses
Precision is essential to fiber optics, where pulses of light are transmitted instead of electricity.
Instead of the typical metal-to-metal transmission in less sophisticated equipment, microscopic
glass fibers must be precisely aligned using fiber optic connectors to allow communication.
There are several types of fiber optic connectors, each appropriate for specific uses.
The Basics
Before describing the fiber optic connectors, it’s important to understand a few key terms about
fiber optic components:
● Simplex. This indicates there is one connector per end.
● Duplex. This indicates there are two connectors per end.
● Ferrule. A thin, often cylindrical structure that forms a tight grip on the glass fiber.
Ferrules typically hold a single strand of fiber and are made from metal, ceramic, or high-
quality plastic.
● Connector body. This holds the ferrule, attaches to the jacket, and strengthens members
of the optic fiber cable. It is usually plastic or metal.
● Coupling mechanism. Part of the connector body, the coupling mechanism holds the
connector in place once it is attached to another device. It may attach to the other device
using various forms, from a latch clip, to a bayonet-style nut and more.
Types of Fiber Optic Connectors
Here are some of the connectors that are used to join together fiber optic components:
● ST. One of the first widely used connectors, the ST or Straight Tip connector stays in
place using a “twist on/twist off” bayonet coupling mechanism and features a 2.5mm
ferrule. They have ceramic ferrules and are rated for 500 mating cycles. The typical
insertion loss for matched ST connectors is 0.25 dB. ST connectors are slowly being
displaced by newer connectors featuring smaller, denser connections.
● SC. Also holding a single 2.5mm ferrule, the SC uses a push-on/pull-off mechanism that
is easier to use than the ST. Unlike the round ST, the SC is square. Two SC fiber optic
connectors are often clipped together to create a duplex connection. Typical matched SC
connectors are rated for 1000 mating cycles and have an insertion loss of 0.25 dB.
● FC. Designed for single-mode and multimode fiber connectors, these are prominently
featured in telecommunications applications. Many people have encountered FC
connectors when hooking up cable, satellite or broadband at home. Featuring a threaded
coupling to hold it in place, the FC uses metal ferrules and is becoming obsolete because
of the cost of its metal housing.
● FDDI. Standard for Ethernet connections, the Fiber Distributed Data Interface features
two ferrules within a large, squared-off connector with a squeeze tab coupling
mechanism. Other similar connectors include the RJ-45. Still found in some places, this
is also becoming defunct technology.
● MTP/MPO. MTP/MPO fiber optic connectors can connect up to 24 fibers within a very
small coupling mechanism. One drawback is that MPO cables must be manufactured;
they cannot be built on-site. To decrease hole wear, and improve guidance and

2. connectivity, the MTP connector uses tightly held tolerance stainless steel guide pin tips
with an elliptical shape. The typical insertion loss for matched MTP/MPO fiber optic
connectors is 0.25 dB.
● MU. Designed for high-density connections over a small, single fiber connector. It can
handle twice the density of a typical SC connector.
● SFF. These are called Small Form Factor connectors and come in several designs.
o LC. Its unique pull-proof latching mechanism and small size make the LC stand
out. It features a 1.25mm zirconia ferrule and is known for its stability in rack
mounts. LC connectors are rated for 500 mating cycles. The typical insertion loss
for matched LC connectors is 0.25 dB.
o MTRJ. Small, square and plastic, these are always duplex and resemble an RJ-
style plug. Insertion loss for matched MT-RJ connectors is typically 0.25 dB.
For more information, or to purchase single-mode fiber connectors or multimode fiber
connectors and other products, please refer to the Precision Fiber Products website.