In-Depth Look at the Fiber Optic Connector

In all fiber optic system, it is necessary to join two fibers together with low signal attenuation while maintaining low reflection levels depending upon the type of system used. Fiber optic connectors are used as the mechanical and optic means for cross connecting fibers and linking to fiber optic transmission equipment. With a wide range of fiber optic connectors with different merits and demerits available on the market, many factors, like performance and cost, should be taken into consideration when choosing a fiber optic connector. Every small decision will post a significant influence on deployments speeds and costs of the fiber optic patch cables. To specifically understand the fiber optic connector, this post will give an overall look of it.

Fiber Optic Connector

An optical fiber connector terminates the end of an optical fiber, and enables quicker connection and disconnection than splicing. The connectors mechanically couple and align the cores of fibers so light can pass. Better connectors loss very little light due to reflection or misalignment of the fibers. In all, about 100 fiber connectors have been introduced to the market. The table below shows some optical connectors.

Commonly Used Types of Fiber Optic Connectors

With so many fiber optic connectors used in fiber optic networks, there are only a few types widely applied. In this part, we will introduce five types of optical connectors

FC Connector

The FC connector was the first optical fiber connector to use a ceramic ferrule, but unlike the plastic bodied SC and LC, it utilizes a round screw-type fitment made from nickel-plated or stainless. The connector end face relies on an alignment key for correct insertion and is then tightened into the adapter/jack using a threaded collet. Although the FC adds complexity both in manufacturing and installation, it is still the connector of choice for precise measuring equipment such as OTDRs. What’s more, the FC connector does make it particularly effective in high vibration environments, ensuring that the spring-loaded ferrule is firmly mated.

ST Connector

Originally developed by AT & T shortly after the arrival of FC, ST or straight tip connector was one of the first connector type widely implemented in fiber optic networking applications. ST connector can be easily mistaken for FC connector at a glance, but the ST uses a bayonet fitment rather than a screw thread. Deployed predominately in multimode datacoms, it is available in network environments such as campuses, corporate networks and in military applications where the quick connecting bayonet had its advantages at the time. Nevertheless, it cannot be terminated with an angled polish, which limits use in single-mode fiber and FTTH applications. It is typically installed into infrastructures that were built at the turn of the century, but nowadays it has almost been swapped out for more cost-effective SC and LC connectors.

SC Connector

The SC or subscriber connector was developed by the laboratories at Nippon Telegraph and Telephone (NTT) in the mid-eighties, which was one of the first connectors to hit the market following the advent of ceramic ferrules. SC connector is a non-optical disconnect connector with a 2.5 mm pre-radiused zirconia or stainless alloy ferrule. It uses a push-on/push-off mating mechanism which is generally easier to use than the twist-style ST connector when in tight spaces. Due to its excellent performance, SC connector has dominated fiber optics for over a decade and now it remains the second most common connector for polarization maintaining applications.

LC Connector

Considered to be the replacement of the SC connector, LC or lucent connector is the most popular small form factor (SFF) connector. Like SC, it is also a push-pull connector, but LC utilizes a latch as opposed to the SC locking tab. Having half the footprint of the SC connector, about 1.25 mm ferrule, gives it huge popularity in datacoms and other high-density patch applications. With more and more density increasingly needed in data centers, the popularity of LC connector will continue growing. The following picture shows the different appearance of FC, ST, SC and LC connector, so you can easily distinguish them.

MPO/MTP Connector

MPO and MTP are compatible ribbon fiber connectors based on MT ferrule which allow quick and reliable connections for up to 24 fibers, so they are larger than the connectors we have mentioned above. MPO and MTP connectors feature male and female connector design. Male connectors have two guide pins and female connectors do not (see in the following image). Both connector types need an adapter to mate a pair of male and female connectors. Since MPO and MTP connectors are trying to align so many fibers at once, their coupling losses are typically bigger than single fiber connectors. This type of connector is extensively used with a fan-out assembly at the opposing end (such as LC, SC, FC etc.) in high-density patching environments, like data centers.

Summary

Knowing the differences among different connector types is necessary to get a deep understanding of the fiber optic connector. Taking time to select the right optical connector for the job can deliver big benefits when it comes to speed and cost. So before making connector choice, please think twice.

The Colorful World of LC Connector

Until few years ago, SC connector was the dominant interface available for fiber optic connections in LANs (local area networks) and data centers. However, the ever-increasing density in network deployment is requiring smaller connection interfaces. As the representative of small form factor (SFF) connectors, LC connector is the most widely used one for high-density connections. When we talking about LC connectors, many of us may think it is just a simple tool to achieve fast and easy field termination for fiber optic connectivity. Actually, the world of LC connector is far more colorful than you think. Besides traditional LC connector, there are various other types of LC connectors which are currently used in different applications. In this post, I’m going to introduce several widely known ones to take you into the colorful world of LC connector.

Features of LC Connector

Actually, connector can be both simplex and duplex. Simplex connector means only one fiber is terminated in the connector, while duplex connector means two fibers are terminated in the connector. The LC has some unique features to make it a preferable connector for high-performance networks.

The ferrule size of LC connector is 1.25 mm which is the half size of SC connector ferrule which is 2.5 mm. This change in size decreases the room by roughly 50% all over the network. LC makes things easier for movement, additions and modifications, thus preventing additional expenses. Besides, the LC connector uses an enhanced edition of the well-known, user friendly RJ-style telephone connector that offers a reassuring and clear click when connected.

Mini LC Connector

The mini LC uses current industry-standard LC connector, but it reduces the center spacing when the duplex clip is added. It is designed with a narrow ferrule pitch to work with the mini SFP (mSFP) transceiver. This accommodates the need for higher port density provided by the transceivers without compromising performance. The mini LC duplex connector looks virtually identical to a standard LC duplex, but is distinguishable with its black duplex clip and its 5.25 mm pitch versus the 6.25 mm used by standard LC duplex connector. The use of mini LC connector with mini SFP transceiver significantly reduces space in data centers. The following picture shows the differences of mini LC and standard LC.

Uniboot LC connector

With two LC connectors encased in a common housing with one boot, uniboot LC connector (shown in the picture below) features a changeable polarity option and reduction in size compared to standard LC connector. It allows the fiber polarity to be reversed at the time of cable assembly installation without exposing the fibers or needing any tools. This not only provides consistent quality and convenience, but also ensures system performance and reduces installation time. Besides, fiber patch cables terminated with uniboot LC connectors, are more preferable in data center applications, since they can offer high efficiency and easier cable management.

Secure Keyed LC Connector

Secure keyed LC connector offers a mechanical network security for organizations wanting to segregate networks due to privacy or security concerns. It is available in 12 colors, and each color represents a unique keying pattern which only allows connection when the color matches. Secure keyed LC connector can not only reduce risks and increase the security of network from incorrect patching of circuit, but also has low insertion loss and excellent durability. The image below shows secure keyed LC connector in different colors.

Push-Pull LC Connector

Before the invention of push-pull LC connector, the LC adapter spacing was limited by the room required to reach the standard LC connector with special tools. And the overall height of standard LC connectors also required a small vertical space above & below the LC adapters. Thanks to the push-pull LC connector or LC-HD connector, these issues can be perfectly solved. LC-HD connector is terminated with a tab which makes it easier to push or pull connector into/out the densely loaded panels without the need for special tools. Besides, the low profile LC-HD connector, together with its push-pull tab allows LC adapters to be stacked with absolutely no vertical space, which increases panel density to its highest possible.

Summary

The world of LC connector is colorful, and when choosing LC connectors, the standard LC is not the only option. There are a range of LC connectors applied in different circumstances can be selected from, such as uniboot LC for easier cable management, LC-HD for space saving and secure keyed LC for safe network transmission. And the evolution of LC connector never stops. With the increasing of various application requirements and the development of technology, there will be more and more new LC connectors to join in. If you need to purchase these LC connectors or LC fiber cables, please visit FS.COM.

Cat5e VS Cat6 Cable – Which One Will You Choose?

With low cost, easy operation and great flexibility, twisted pair cables are widely used in telephone communications and modern Ethernet networks. Nowadays, there are many categories of twisted pair cables available on the market, such as cat3 cable, cat5/cat5e cable, cat6/cat 6a cable, and cat7 cable, etc. Today, I’d like to give a brief but complete discussion about two common categories—cat5e and cat6, which are so similar to each other that the general public may feel confused to know which cable is suitable for their tasks.

What Is Cat5e Cable?

Cat5e is an enhanced specification of the cat5 standard which was introduced to the market in early 2001. While similar to cat5 cable in appearance, cat5e cable introduces some new links in the equation. For one thing, cat5e cable uses four pairs of copper wire rather than the two that cat5 cable relies on. In addition, the wire pairs are twisted more tightly to eliminate crosstalk. Due to its internal upgrades, including faster transmission rate and higher bandwidth, cat5e cable has become the most common type of cabling found in modern homes and offices for Ethernet purposes. The following picture shows Cat5e cable.

What Is Cat6 Cable?

Only a year after cat5e was introduced, a new standard—cat6 was born. The cat6 standard improved upon the cat5e by increasing frequency responses, tightening crosstalk specifications, and introducing more comprehensive crosstalk specifications. Usually, cat6 cable (shown in the picture below) consists of four unshielded twisted pairs (UTP) terminated with RJ45 connectors, which is often used for 10Base-T (Ethernet), 100Base-TX (Fast Ethernet), 1000Base-T (Gigabit Ethernet) and 10GBase-T networks.

Differences Between Cat5e and Cat6 Cables

Transmission Speed

When we think about advances in cabling, transmission speed is the first thing that should be taken into consideration. As we mentioned previously, cat6 cable can be used to power 10GBase-T or 10G Ethernet, while the maximum speed that cat5e cable can support is 1GBase-T or 1G Ethernet. This is because cat6 cable performs up to 250 MHz, which is more than twice that of cat5e cable (100 MHz). 

Distance

Since cat5e and cat6 are made of copper wires, both of them are only available for short distance data transmission. If the cable is used for lower data rate transfer, both cat5e and cat6 cable can support the length of up to 100 m. However, when the data rate achieves the maximum speed, cat5e cable can reach 50 m, while cat6 cable can only reach 37 m.

Cost

In general, cat6 cables are 10 to 20% more expensive than cat5e cables. However, cables are comparatively cheap which makes the cost differences between cat5e and cat6 cables come to be very small portion of the total network budget. Besides, the speed boost offered by cat6 cables usually makes the price premium worthwhile, especially in long run transmission.

Reliability

When installing a network, many users may concern whether there will be electrical interference that can negatively influence the performance of their network. Compared with cat5e cable, cat6 cable has improved reliability that it can deter signal interference from affecting your network. You’ll be able to have a longer and more reliable period of uptime, regardless of how close you are to other network connections in your area. The following table shows some differences between cat5e and cat6 cables.

Conclusion

Cat5e and cat6 cables are two commonly used categories of twisted pair cables. They are different from supporting distance, transmission speed, cost, and reliability. After reading this post, hope you can choose the right one for your project. If you need cat5e, cat6 or other types of twisted pair cables, FS.COM is a good place to go. Besides these copper cables, we also supply a wide range of fiber patch cables with different connectors, such as SC, FC and LC connector. For more information, please visit FS.COM.

Things You Should Know About Fiber Optic Connector

With the fast development of fiber optic technology over the past  years, fiber optic connector has traditionally been the biggest concern in  fiber optic systems. So what is fiber optic connector? Fiber optic connector, also named fiber connector or optical fiber connector, is designed to terminate the end of fiber optics, which can be repeatedly used for connecting two fibers or fiber optic cables to form a continuous light path. Every fiber connection has two values-attenuation (insertion loss) and reflection (return loss). A better connector loses little light because of misalignment or reflection of the fibers. And a fiber optic connector which is lower loss, lower cost, easier to terminate or solved some other complicated problems is really needed for the phonetic industry. Thus about hundreds of fiber optic connectors have been introduced to the market with different standards and applications, but only few of them can represent the majority of the market.

There are several commonly used types of fiber optic connector including LC, SC, ST, FC, MU, MTRJ, E2000, SMA and MTP/MPO connector. Each of different types of fiber optic connector offers its advantages and disadvantages, and it can be applied to which it’s better suited according to its specific application.

LC Connector (Lucent Connector): LC is a small form factor connector that uses a 1.25mm ferrule, which is only half size of the SC,ST and FC fiber optic connectors. It is considered by some people that it can replace the SC connector, because it is stable and simple. The LC connector can be used in mutimode (beige), single-mode (blue) and in a non-reflective design (green). This type of high-density connector is needed in many pieces of communications technology, such as SFP and XFP transceiver.

SC Connector (Subscribe Connector): SC is a snap-in connector with a 2.5mm ferrule which was one of the first connector to hit the market following the advent of ceramic ferrules. And it is a connector that latches with a simple push-pull motion. It is widely used due to its excellent performance and it is very popular with the industry because it can be manufactured at a low price and it actually works. The SC connector is perfectly suited for telecoms and datacoms. Nonetheless its size is the only disadvantage.

ST Connector (Straight Tip): ST is a slotted bayonet type connector with long ferrule, about a 2.5mm ferrule.After the advent of the FC, it was developed by AT&T. Most ST are ceramic, but some can be metal or plastic. And it is a connector for multimode network, like working buildings, corporate networks and in military applications.

FC Connector (Ferrule Connector): FC was the first fiber optic connector to use a ceramic ferrule and was one of the most popular single-mode connector for many years. It also uses a 2.5mm ferrule, like SC and ST. Because it is usually used with single-mode fiber optic cables, many datacom and telecom systems employ FC connectors for this purpose. Nevertheless it has been almost replaced by LCs and SCs.

MU Connector (Miniature Unit): MU looks like a miniature SC with a 1.25mm ferrule. It also has the same push-pull motion, but it can fit two channels in the same footprint of a single SC. It is often used in high-speed data communications, voice networks, telecommunications, and DWDM(wavelength division multiplexing).

MTRJ Connector (Mechanical Transfer Register Jack): MTRJ was considered to be the FTTD (Fiber To The Desk) connector for some time, which has two fibers and is just as small as a RJ45 connector. And it uses a 2.45×4.4mm ferrule. The MTRJ connector is suitable for indoor application in telecommunications and data network system.

E2000 is a trademark of Diamond Company and it has varieties of styles. Even though E2000 connector is more expensive than most of the other connectors, it is widely used in the world of telecommunications, because it has high quality and spring-loaded protective cap that provides increased safety protection. The E2000 connector is available for single-mode and multimode applications.

SMA Connector (Sub Miniature Version A): SMA connector is semi-precision coaxial RF connector developed in the 1960s with a 3.14mm ferrule. Due to its compact size and excellent durability, this connector and related products are widely used in media, sensor and fiber optic test application.

MTP/MPO Connector: MTP and MPO are compatible ribbon fiber connectors based on MT ferrule which allow quick and reliable connection. A MPO connector is the industry for “multi-fiber push on”, while the MTP connector is a high performance MPO connector with multiple engineered product enhancement to improve optical and mechanical performance when compared to MPO connectors. A single MPO/MTP connector can suspend the combination of 4, 8, 12, 24, 48 fiber ribbon cables. MTP/MPO connectors features male and female connector design. Male connectors have two guide pins while female connectors do not. MTP/MPO fiber optic connectors are used extensively, both at single-mode and multimode wavelengths., in high density patch environments such as data-centers.

In conclusion, there are so many different types of fiber optic connectors and each of them has unique applications. If users read this article carefully, it will be useful for them to choose a connector they need.