SC vs LC sfp：What's the difference?

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.

SC vs LC: How They Differ From Each Other

After having a basic understanding of both SC and LC connector, you may ask what are the differences and what do they mean to your implementation? The table below gives an overview of strengths and weaknesses. And generally speaking, the difference between LC and SC fiber optic connector lies in the size, the handling and the connector history, which will be discussed respectively in the following text.

• Size: LC is half the size of SC. Actually, one SC-adapter is exactly the same size as a duplex LC-adapter. Therefore LC is more and more common in central offices where packing density (number of connections per area) is an important cost factor

• Handling: SC is a true “push-pull-connector” and LC is a “latched connector”, although there are very innovative, real “push-pull-LCs” available which have the same handling capabilities like SC.

• The History of Connector: The LC is the “younger” connector of the two, SC is wider spread around the world but LC is catching up. Both connectors have the same insertion loss and return loss capabilities. Generally, it depends where in the network you want to use the connector, no matter SC or LC, even the other different kinds of connector.

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.

The realm of optical communication technology contains a requisite plethora of acronyms and terminologies, with SC and LC being among the essential ones in the context of SFP modules. SC (Standard Connector or Subscriber Connector) and LC (Lucent Connector) are two types of optical connectors deployed within the framework of small form-factor pluggable (SFP) optical modules. Understanding the differences between SC and LC SFPs provides critical insights into the adaptation of various networking situations.

SC connectors were the first generation of connectors popularly used in optical communication. An SC connector is known for its push-pull coupling end-face, making it easy to engage and disengage from the contact. It uses a ceramic ferrule to hold the fiber and ensures precision alignment for the connection. However, the physical dimensions of an SC connector are relatively large, which could limit the port density of certain applications requiring more compact solutions.

On the other hand, LC connectors, often referred to as 'Little Connectors', are smaller than SC connectors, approximately half the size, making them a more suitable choice for systems requiring high-density solutions. The LC connector uses a smaller 1.25mm ferrule that offers excellent performance and is ideal for Single Mode Applications. Incorporating a secure latch mechanism, much like an RJ-45 connector, LC connectors provide reliable and stable connections. Their small form factor has made them the most popular choice for use with SFP transceivers.

Both SC and LC connectors provide high performance and reliability, maintaining low insertion loss and high return loss, essential parameters in optical communications. However, the significant difference in physical size means they cater to different application levels. 

LC SFP modules are often the preferred choice in telecommunications and data communications applications, particularly where interface size matters. These modules are commonly used in Gigabit Ethernet, Fibre Channel, and other industry standards. Given their compact footprint, the LC SFP modules provide higher port density on switches and other networking equipment compared to the SC type.

In contrast, SC connectors, because of their robustness and ease of use, are mainly used for Cable TV and other residents' broadband connections, where high density is less crucial.

In summary, while both SC and LC connectors offer reliable performance and low loss connections, the choice between them in SFP modules depends predominantly on the application’s requirements, space availability, and the desired port density. As the demand for higher bandwidth continues to surge, LC SFP modules, due to their compact size, will remain the more popular choice for many fast-growing industry sectors such as telecommunications and data centers. Yet, the SC will continue to be relevant in settings where its robustness and ease of use are more critical than port density.

 

What do SC SFP and LC SFP represent respectively?

What is SC SFP?

The complex data highways of our modern digital world rely heavily on an array of intricate communication technologies. Among these, the Small Form-factor Pluggable (SFP) transceivers that feature Standard Connectors (SC) warrant specific recognition for their contribution to robust, efficient, and reliable data communications.

The term SC SFP refers to an SFP optical transceiver that uses the Standard Connector, often referred to as Subscriber Connector or Square Connector, for coupling and transmission. SC is a type of optical connector introduced in the late 1980s and characterized by its square shape, push-pull coupling mechanism, and high packing density.

In an SC SFP transceiver, the fiber optic cables are terminated with SC connectors, which interface with the corresponding SFP port on a switch or other network devices. The SC connector uses a ceramic ferrule to house the fiber, ensuring accurate alignment and robust connection stability. This type of connector is known for its excellent performance with low insertion loss and high return loss, crucial parameters in optical transmission systems.

Notably, SC connectors are user-friendly, with a simple push-pull mechanism that allows for quick and straightforward insertion and removal. This feature facilitates easy maintenance and changes in network configurations, saving significant time and effort on the part of network operators.

However, SC connectors are larger than some other types of connectors, such as LC (Lucent Connector). This size difference means that SC SFP modules occupy more space on a switch or router, limiting the port density. Consequently, while SC SFP modules offer excellent performance, they may not always be the optimal choice for high-density applications like data centers, where space optimization is essential.

Typically, you'll encounter SC connectors in applications such as Cable TV, analog optical communication, or any environment where high-density solutions aren't a priority. They are particularly popular in Gigabit Passive Optical Networks (GPON) and other types of fiber to the home (FTTH) or fiber to the building (FTTB) networks.

In conclusion, SC SFP optical transceivers offer an efficient and reliable solution for data transmission in many optical communication networks. While their larger size may limit their application in high-density environments, their ease of use, robust performance, and proven longevity make them an enduringly popular choice in many other networking scenarios. As our digital world continues to evolve and diversify, it's clear that SC SFP modules will continue to play an integral part in supporting our ever -growing data communication needs.

• Compatible for Cisco GLC-BX-U and GLC-BX-D.

• 1000BASE-BX-U and 1000BASE-BX-D Bidirectional SFP Optic, up to 20km over single SC.

• SFP Bidi Transceiver, 1.25Gb/s SFP Bidi, Single SC connector

• Wavelength: Up: TX1310nm/RX1490nm; Down: TX1490nm/RX1310nm.

• 100% Compatible with Cisco for various brands of switches and routers. Each transceiver is individually tested before delivery.
  
   

What is LC sfp?

As we navigate the labyrinth of digital communication technologies, the Small Form-factor Pluggable (SFP) transceiver using Lucent Connectors (LC), frequently referred to as LC SFP, stands out as a robust, compact, and efficient solution. A significant driver in data network systems, LC SFPs are paving the way for high-speed communication capabilities.

LC SFP is an optical transceiver module employing LC-type connectors -- a widely accepted standard for optical fiber connectors in the communication industry. "LC" stands for Lucent Connector, named after Lucent Technologies, which first developed this type of connector. It is also often referred to as "Little Connector" because of its diminutive size compared to other connector types, like the SC (Standard Connector).

The LC SFP module was designed to support data rates from 155 Mbps up to 10+ Gbps, meeting the growing demands of high-speed telecommunication and data communication networks. Owing to its small form-factor, LC SFP modules provide higher port density, enabling more connections on a single device and maximizing space efficiency -- a considerable benefit for densely populated applications such as data centers.

LC connectors in LC SFP modules feature a 1.25mm diameter ferrule -- half the size of an SC connector -- which is excellent for single-mode fiber applications where precision is indispensable. Moreover, their secure latching mechanism provides a stable connection, ensuring high performance and minimal signal loss.

Like most other SFP modules, LC SFPs are hot-pluggable, allowing for smooth insertions and removals without needing to power down the network system. This feature significantly reduces downtime, making network upgrades and maintenance more efficient and less disruptive.

LC SFPs are widely used across a spectrum of applications, covering Ethernet, Fibre Channel, SDH/SONET, and other industry-standard protocols, marking their versatility in handling diverse communication standards. They are available in a range of types to suit different distance and wavelength requirements, from short-reach (SX), long-reach (LX), extended reach (EX), and ultra-long reach (ZX).

In conclusion, LC SFP modules exemplify how critical components in data networking have adapted to meet escalating data rate demands while maintaining space-efficiency. Compact yet powerful, LC SFPs have become an integral element supporting the backbone of our digital world, driving the data highways of countless high-speed networks. As data networks continue to expand and evolve, LC SFPs will undeniably continue to play a pivotal role in delivering high-frequency communications and meeting our ever-growing digital demands.

When selecting a particular SFP how do we determine whether it requires an LC or SC fibre cable?

e.g. GLC-LH-SMD (Cisco GLC-LH-SMD 1000BASE-LX/LH SFP transceiver module, MMF/SMF)

Do I order an SC interface fibre cable to connect into this or an LC fibre cable?

e.g 10GBASE-LR does this take an LC interface or SC interface?

all SFP and SFP+ optics require LC connectors so the question becomes when you need single mode fiber or multi mode fiber but the connectot type is clear.

SC   square connectors are too big to fit in a SFP or SFP+.

GLC-LH-SMD -> equires Sngle Mode LC terrminated fiber pair

the only execption are SFP that support an RJ45 LAN cable.

Summary

Present and future communication technology demand fast, efficient and safe performance in the data communication process. Large and complex databases all interconnected must be able to receive and transmit data without outside interference. Both SC and LC are designed to achieve such a kind of transmission. As for the question “SC vs LC: what’s the difference and which one is better?”, you just need to keep three basic points in mind: 1. SC has a larger connector housing and a larger 2.5mm ferrule. 2. LC has a smaller connector housing and a smaller 1.25mm ferrule. 3. SC used to be all the rage, but now it’s LC. You can fit more interfaces on line-cards, panels, etc with LC connector.