LC Connectors: Everything you need to know


Are you interested in LC connectors but unsure of where to start? Then you’re in the right spot! We’ve written up this article to help you along the way.

You might be wondering what exactly uses an LC connector? There are many applications for an LC fiber connector. They include data communication centers, networking, telecommunications, medical, government, and high-density installments. Generally, LC connectors are the most popular on the market today.

This article covers the characteristics of an LC connector while providing information on the different connector types. 

Table of Contents

1. What is an LC Connector?

LC Connector

A Lucent Connector (LC) is a popular ceramic ferrule connector commonly used for devices that don’t have room for a fiber-optic connection. An LC connector is generally faster and simpler to operate than the other types.

LC-compatible transceivers and networking components are gaining popularity; LC connectors are likely more widely-used in the FITH arena. The performance is generally great while praised for single-mode use. These connectors are also for small form-factorable modules and fiber optic extenders.

What does an LC connector look like?

The LC connector has a plastic housing with push-pull design that utilizes a latch instead of a locking tab to secure it in place. It’s also a small form factor (SFF) connector.  These connectors come in three different colors: beige (multimode), blue (single-mode), and green (angle polish).

LC connector types

 There are a few types of LC connectors to consider. Below, we’ve outlined each of them.

*UPC vs. APC

Fiber connectors implement either Ultra Physical Contact (UPC) or Angled Physical Contact (APC). Any cable that utilizes one of these has the suffix -UPC or -APC. You can classify a fiber connector with ST connectors as ST-UPC or ST-APC.

A UPC connector has special polishing to modify the connector’s internal glass. This allows laser signals to move through easily, which improves the speed. However, this also means that the glass is prone to damage. Plugging/unplugging a UPC fiber cable increases the risk of wear and tear.

On the other hand, APC connectors have an eight-degree angled polish. This is a big advantage because it keeps the connection secure while minimizing damage. However, there is one drawback: the connector needs to have a right-side-up insertion compared to UPC and traditional connectors.

*Simplex vs. duplex

Fiber cables are available in simplex or duplex. Simplex connectors, which are common for replacements or repairs, contain a glass or plastic fiber strand. Applications requiring a one-way data transfer use a simplex connector, available in single-mode or multi-mode. 

Meanwhile, duplex connectors have two strands of glass or plastic fiber. These contain a zip-cord arrangement, which is ideal for bi-directional communication transfer. There are two types of fiber cables used in data transmission: half-duplex and full-duplex. Half-duplex involves one-way data transmission. Furthermore, full-duplex is where data transfer occurs in both directions simultaneously.

LC connector dimensions

 An LC connector has a 1.25mm ferrule, which is half the size of other connector types.

LC connector adapter

An LC connector adapter allows easy cable connectivity. Typically, they’re available in simplex and duplex for both single-mode and multimode fiber connectors. These adapters have applications in both outdoor and indoor terminal boxes.

Adapters come in a variety of colors: beige, green, blue, and aqua. These feature a built-in aligned metal or ceramic casing, snap or screw mounts. Adapters could also have safety shutters for protection.

2. Other fiber connector types



Fixed Connection (FC) connector has a 2.5mm ferrule and contains a threaded connection composed of nickel-plated or stainless steel, taking them longer to disconnect. These threads can keep the cable locked-in when paired with mobile machinery. Even though it’s complex to manufacture and install, the FC connector can measure equipment like OTDRs. 

Once introduced, FC connectors gained popularity for data communication and telecommunications. However, FC connectors are not as common today due to the emergence of SC and LC.



You can use a Straight Tip (ST) connector in corporate networks, campuses, and military applications. It contains a 2.5mm ferrule and utilizes a bayonet fitment. The fiber secures in place via a long cylindrical ferrule. Developed by AT&T, the design allows easy insertion and removal. Typically, ST connectors have an Insertion Loss of 0.25dB. Reconnecting this connector resolves high light loss. 

There are two types of ST connectors: ST and ST-II, which have keyed and spring-loaded features, respectively. These are push-in and twist types and have 500 mating cycles. ST connectors have fewer implementations than in past decades for the same reasons as FC connectors.



The Subscriber Connector (SC) has replaced the ST connector, making it the most popular one due to its high performance. Created by Nippon Telegraph and Telephone (NTT), this type uses a spring-loaded 2.5mm ferrule, providing precise alignment. It has a push-pull design that secures the unit via a locking tab. The SC connector has a molded housing, which provides protection.

The SC connector is inexpensive, durable, easy to use, and widely popular among telecom and datacom industries. It’s also for polarization applications. SC connectors have a rating of 1000 mating cycles with a 0.25dB Insertion Loss.



An MTP/MPO connector is larger than other types because they support 24 fibers in a ferrule. These are more suitable for a data center that requires a lot of connections. Breakout cables have MTP/MPO on one end and a series of LC or SC connectors on the opposite end. Additionally, they can host 12 simplex or 6 duplex connections. Breakout cables cut down on installation time by using less connected cables. 

3. Changing lc to sc connector

Do you have an LC connector but quickly realized you need SC? There’s a simple solution to that problem. Purchase an LC-LC coupler and a pre-terminated LC to SC patch cable. You can also use an adapter to implement the changes.


Overall, when it comes to connectors, the LC type is the best and most popular choice. We are here to provide you more professional ideas.  Be sure to contact us if you have any questions or need assistance with cable assembly services.