Welcome to QSFPTEK Global     Free shipping on orders over US$ 79.8     US and Poland Local warehouse

Contact Us


Free shipping on orders over US$ 79.8

Fiber Connector Types - LC vs SC vs FC vs ST vs MTP vs MPO

Author Derek

Date 12/20/2021

Fiber connector types LC, SC, FC, ST, MTP, and MPO are widely used in past and present. What are the differences between them? Who is the most popular one? Find the answer in the article.

What is a Fiber Connector?

The fiber connector is a kind of detachable passive optical component used in the connection between fiber to fiber, the light source to the fiber, and fiber to the detector to achieve the light maximize coupling to the receiving fiber. According to the estimating, there are hundreds of different fiber connector types on the market. However, the widely used types are about a dozen of fiber optic connectors, which can be divided into single-fiber, duplex fiber connectors (such as FC, LC, SC), and multi-fiber connectors (such as MTP/MPO).


Fiber connector is associated with the reliability and performance of optical transmission systems. A better connector loses very little light due to reflection or misalignment of the fibers. 


A good fiber connector can be measured as the following factors:

- Low loss.

- Small-size and lightweight.

- Ease of installation and operation.

- Low cost.

- High reliability.


The survival of the fittest. In today’s data center applications, small, simple, and multi-fiber fiber connectors have gradually replaced larger and complex types, achieving higher density fiber ports per unit of rack space. Next, this article will introduce the widely used fiber connector types in the past and present including FC SC LC ST and MTP/MPO connectors one by one.


Fiber connector types of LC, SC, FC, ST, MTP, MPO


Fiber connector types of LC, SC, FC, ST, MTP, MPO


LC vs SC vs FC vs ST vs MTP vs MPO


Fiber Connector Types


Connection Type



1.25 mm


IEC 61754-20


2.5 mm


IEC 61754-4


2.5 mm


IEC 61754-2


2.5 mm


IEC 61754-13


2.5 mm





Fiber Connector Types - SC

SC fiber connector stands for square fiber optical connector, which features a square push-pull structure. The ferrule diameter of the SC is 2.5mm. There is a spring inside the flange and if you hear the springs twanged when you insert the connector into the flange, that means the connector has been properly connected.


SC is usually used in Gigabit Ethernet networks, datacom, and telecom applications. With the advantages of low price, easy push-pull operation, low insertion loss, good compression strength, etc, it has been widely used since the 1990s with only the ST competing with it.


SC Connector Structure


SC Connector Structure


Fiber Connector Types - FC

FC (Ferrule Connector) features a round screw structure. The screw installation of the FC is a little more complicated than the push-pull SC fiber connector. It must be done very carefully when aligning the key, furthermore, there is also the risk of scratching the fiber end face when inserting the ferrule into the jack. Same with the SC, the ferrule diameter of the LC fiber connector is also 2.5mm.


FC connector is generally used in datacom, telecom, measurement equipment, single-mode lasers, etc since it was introduced. However, it has been gradually replaced by SC and LC, which provide the equivalent performance of FC but get a faster connection speed yet.


FC Connector Structure


FC Connector Structure


Fiber Connector Types - LC

LC fiber connector adopts a modular jack latch structure, which has a great advantage of ease-operation. The ferrule diameter of the FC is only 1.25mm, which is half of SC and FC connectors. The small size contributes to increasing the density of fiber connectors housed in optical fiber wiring frames.


The LC connector has dominated the market. It has been widely used in both single-mode and multimode SFF (Small Form Factor) transceivers and gradually replaced SC due to its smaller size.


LC Connector Structure



LC Connector Structure

Multimode LC Fibers & Single-mode LC Fibers

Multimode LC Fibers & Single-mode LC Fibers


Fiber Connector Types - ST


ST optical connector features a bayonet structure. Similar to the FC, the index tab must be carefully aligned with a slot when insertion. Besides, because of the spring-loaded structure, ST fiber optical connector takes a lot of energy to push and twist the connector. Same as SC and FC, the ferrule diameter of the connector is also 2.5mm.


ST is typically used in multimode datacom, however, it has also been replaced by SC or LC connectors.


ST Connector Structure


ST Connector Structure


Fiber Connector Types - MTP/MPO

The development of fiber connectors can be divided into two stages. The one is the development from FC, ST, SC connector to LC, which aims to achieve space-saving and miniaturization. The other is the evolution of LC to MTP/MPO, which aims not only to achieve space-saving but also fulfill the multi-fiber application requirement. An MTP/MPO connector has a capacity of 2-fiber, 4-fiber, 8-fiber, 12-fiber, 24-fiber, even up to 72-fiber.


MTP connectors are used interchangeably with MPO. They are typically applied in high-speed data center and LAN applications.


MTP/MPO Connector Structure


MTP/MPO Connector Structure



Frequently Asked Questions About Fiber Connectors

1. What is the difference between LC and SC fiber optic connectors?


LC vs SC Size - LC is smaller than SC, which is half the size of it. The diameter of the LC is 1.25mm while the SC is 2.5mm, thus LC is more friendly to high-density applications. Its small size allows twice the port density on a faceplate than an SC connector does.

LC vs SC Connection Handling - LC connector features with latch structure and designs with a locking tab to secure the cable, whereas SC features with push-pull structure and locks in place with a latch to secure the cable.


2. How to terminate SC with LC connector?

SC to LC adapter assemblies can help connect an SC connector to an LC connector. The SC-LC fiber which separately terminates an SC interface and LC interface at both ends is also useful.



LC to SC duplex OS2 fiber

The above article has comprehensively introduced the LC, SC, FC, ST, MTP, and MPO fiber connector types, including their appearances, structures, applications, etc. If you still have any confusion about fiber connectors or need fiber optic cables with different fiber connectors types, QSFPTEK customer experience representatives and tech support is available round-the-clock to help you at sales@qsfptek.com.


Contact us