Fiber optic connectors are critical components in fiber optic networks, enabling the connection of optical fibers with minimal signal loss. These connectors come in various types, each designed to meet specific performance and application requirements. Below is an overview of the most common types of fiber optic connectors.
What Is a Fiber Optic Connector?
An optic fiber connector is used to connect two ends of optic-fiber cables. It allows for quick connection or disconnection of optic fiber cables without splicing. Optic fiber connectors usually feature a ferrule that helps keep the fiber in place and align strands of fibers to pass the light. A fiber connector is considered an important part of an optic-fiber cable. It plays an important role in stable optic fiber transmission.
Types of Fiber Optic Connectors
Choosing the right types of fiber optic connectors is important. It affects how well your network connects and performs. Here are the most common types of fiber optic cable connectors
LC Connector (Lucent Connector)
LC means lucent connector or little connector, which features a 1.25mm ferrule. It is a type of small form factor connector (SFF connector). It was developed by Lucent Technologies. They also features a push-and-pull design. Because of their tiny size, LC is very suitable for high-density installation in FTTH and panels. LC connectors can be divided into simplex and duplex structures. LC connectors also have polarized design for stable transmission.
SC Connector
The SC fiber connector became the first connector to meet the TIA-568 standard and features a snap-in design that latches with a simple push-pull motion. The “SC” stands for “Square Connector” due to the “square-shaped” connector body. It adopts a 2.5mm ferrule, which is twice the size of the previous LC connector. The SC fiber optic connector works ideally for datacoms and telecom applications, including point-to-point and optical networking setups. Due to its excellent performance, fiber optic SC connector remains the second most common connector for polarization maintaining applications.
ST Connector
ST (Straight Tip) fiber optic connector was created and licensed by AT&T shortly after the arrival of the FC type. The ST optic connector holds the fiber with a ceramic, spring-loaded 2.5mm ferrule that stays in place with a half-twist bayonet mount. People commonly use them for both long and short-distance applications, including campuses, building multimode fiber networks, corporate network environments, and military settings.
FC Connector
FC stands for “ferrule connector”. It is the first fiber optic connector to use a ceramic ferrule. However, unlike the plastic-bodied SC and LC, it uses a circular screw-type fitting made of nickel-plated or stainless steel. The alignment key positions the FC fiber optic connector’s end face, and the user screws it into the adapter/jack with a fiber collet.
MTP/MPO Fiber Connector
The Multi-Fiber Push-On and Multi-Fiber Termination Push-On (MPO and MTP) connectors revolutionize fiber optic connectivity by accommodating multiple fibers within a single connection. These connectors can support configurations of 12, 24, or even 36 fibers, making them indispensable in high-density applications where space is at a premium. Notably, the MTP connector is an enhanced version of the MPO, offering superior performance and accuracy.
MT-RJ Connector
MT-RJ stands for Mechanical Transfer Registered Jack. It is a duplex connector with female and male variants employing alignment pins. MT-RJ is almost no longer in use. Specific systems, however, may still require these connectors for maintenance. MT-RJ is only compatible with multimode duplex cables. Both fibers enter the ferrule, connected to its mated half via pins and holes, much like the MPO/MTP connector.
MU Connector
The MU (Miniature Unit Coupling) connector was developed by NTT, just like the Mini-SC. But unlike the SC, the MU connector has a 1.25mm zirconia ferrule. It uses a simple push-pull design, a compact miniature body, and a self-holding mechanism for backplane applications.
DIN Connector
The DIN connector is round with pins arranged in a circular pattern. It encompasses several types of cables that plug into an interface to connect devices. Typically, a full-sized DIN connector has three to 14 pins with a diameter of 13.2 millimeters. It is applied for PC keyboards, MIDI instruments, and other specialized equipment.
E2000 Connector
The E2000 Connector is a push-pull coupling mechanism with an automatic metal shutter in the connector as dust and laser beam protection. E2000 fiber optic connector features a one-piece design that enables easy and quick termination, making it ideal for high safety and high power applications.
Factors to Consider When Choosing Fiber Connectors
Fiber Optic Cables
There are two basic types of fiber optic cables: single mode and multimode. Is your fiber optic cable single mode or multimode? Single mode fiber optic cable allows for one light mode to propaganda at one time, while multimode means that multiple light modes can pass through the fiber. The multimode also features a larger central core than the single mode to allow for different rays of light. You can identify whether the cable is single mode or multimode by the jacket color.
In general, the single-mode cable comes with a yellow or blue jacket and a multimode cable feature an orange or green cover. Fiber connectors also come in single mode and multimode. And single mode fiber connectors usually have blue or green covers, while multimode connectors feature beige covers. But different manufacturers may have different color choices, so you’d better verify it from the suppliers before buying.
Polish Type
Remember the Polish type. Fiber optic connectors are available in PC, UPC, and APC polish. Therefore, we can divide them into three categories: PC, UPC, and APC connector; different polishes offer different performance and cost differences.
- PC Polish: PC polish is the original polish type. It looks like a flat fiber connector, but in fact, it is polished with physical contact. PC fiber connector features a slight cone design to reduce the air gap, achieving a lower optical return loss (ORL). The reflection loss of this polish type is about -40dB.
- UPC Polish: UPC means ultra physical contact, which is an advancement of PC polish. It has a better fiber surface finish than PC polish, so it has a lower optical return loss (ORL). We commonly use UPC polish in our daily lives, especially for TVs, telephones, and network systems. The reflection loss of this polish type is about -50dB. “But please note that the quality of fiber surface polish directly influences the lower optical return loss, so it’s better to choose fiber connectors from well-known suppliers.”
- APC Polish: APC connectors have a ferrule end-face polished at an 8-degree angle, which reduces reflection loss. But when you choose an APC connector, you should pair it with other angled-polish connectors or it will cause high insertion loss. The ORL (optical return loss) of the APC connector is about -60dB or higher.
Termination Type
Field termination, as its name implies, is to terminate the end of the fiber in the field. The procedure includes strip the cable, prep the epoxy, apply the connector, polish, inspect and test for the connection, requiring not only a large number of tools but also skilled technicians to conduct the termination.
Factory termination, also called factory pre-termination, refers to cables and fibers terminated with a connector in the factory. The pre-terminated cables come in pre-measured lengths with the fiber optic connectors already installed with factory-level precision and quality assurance. Reducing the cumbersome process and tools, factory pre-terminated solutions are easier to install and require less technical skills.
Conclusion
Understanding the various types of fiber optic connectors is essential for selecting the right connector for specific applications. Each type offers unique features and benefits, making it suitable for a range of environments, from high-density data centers to rugged industrial networks. Evaluating factors like application requirements, environmental conditions, and future scalability can help ensure the optimal choice for your fiber optic network. Contact Hubtech for hep with any fiber solutions.
