Four Common Types of Fiber Optic Connectors

When installing a brand new fiber optic network, you have to join two fibers together with low signal attenuation. Typically, there are two ways to link optical fibers: fiber optic splice and the use of fiber optic connectors. Fiber optic splice is an important method of joining two fiber optic cables together. While by using fiber optic connectors, you can connect two fibers more easily and quickly than splicing. Generally, there are many different kinds of connectors for fiber optic cabling. This post introduces four common types, which are LC connectors, FC connectors, ST connectors, and MPO connectors.

LC (Lucent Connector, Little Connector, or Local Connector) connectors are small form-factor fiber optic connectors with 1.25 mm ferrules, half the size of SC connectors. They are standard ceramic ferrule connectors, which can be easily terminated with any adhesive. LC connector is one commonly used connector type for fiber optic patch cords. There are many kinds of LC fiber optic cable, such as LC to LC multimode fiber optic patch cable (as shown in following picture), or LC to LC single mode fiber patch cable. LC connectors with good performance are highly favored for single-mode fiber optic cables. Available in simplex and duplex versions, these connectors incorporate a unique latching mechanism providing stability in system rack mounts. LC connectors have a locking tab. They are rated for 500 mating cycles. The typical insertion loss for matched LC connectors is 0.25 dB.

FC (Ferrule Connector or Fiber Channel) connectors are constructed with a metal housing and are nickel-plated. They have 2.5 mm ceramic ferrules and are rated for 500 mating cycles. These connectors offer extremely precise positioning of the fiber optic cable with respect to the transmitter’s optical source emitter and the receiver’s optical detector. FC connectors are used for single-mode and multimode fiber optic cables. They are covered in TIA connectors intermateability standard FOCIS-4 (TIA-604-4). The insertion loss for matched FC connectors is 0.25 dB.

ST (Straight Tip) connectors used in patch cords employ half-twist bayonet locking mechanism and high quality 2.5 mm zirconia ferrules. They are rated for 500 mating cycles. ST connectors can be inserted into and removed from a fiber optic cable quickly and easily. ST connectors come in two versions: ST and ST-II. These are keyed and spring-loaded. Other than standard single-mode and multimode fibers, OM2 and OM3 fibers are also available for these connectors. The typical insertion loss for matched ST connectors is 0.25 dB.

MPO (Multi-fiber Push On) connectors (as shown in following picture), use tightly held tolerance stainless steel guide pin tips with an elliptical shape. These connectors are designed to improve optical signal performance. MPO connectors are used with single-mode and multimode fiber optic cables. And they are manufactured specifically for multifiber ribbon cables. MPO connectors can provide reliable high performance interconnects of up to 24 fibers in a small footprint. They utilize the precision molded NTT compatible ferrule which connects four to 24 fibers using bare ribbon or ruggedized ribbon cable. The typical insertion loss for matched MPO connectors is 0.25 dB.

Fiber optic connectors are the most widely used passive optical components in fiber optical transmission, optical distribution frame, optical test instruments and instrument panels. Given that there are so many different kinds of connectors, identifying the best connector for your application can be overwhelming. Typically, choosing the suitable fiber optic connector for any installation not only provides perfect performance for your job, but also saves time. So it is a good idea to take the time to investigate your options before making your connector choice.