MT Ferrule – The Key Component for High-Density Fiber Optics Connectors

The MT ferrule is the key component for high-density fiber optic connectors. Its elliptical shape minimizes accidental bumps during mating and reduces debris generation over time.

However, compared to cylindrical ceramic ferrules, the MT’s polymer material and polishing techniques make it more difficult for assembly manufacturers to achieve low connection loss.

Size

The size of an mpo-ferrule determines the number of fibers that can be connected in the connector and its performance. It also determines the compatibility between different connector manufacturers. The mpo-ferrule is typically 12.5mm in diameter, which enables the housing to accommodate multiple fibers without compromising on strength or space.

There are various options in mpo-ferrule sizes, ranging from 4 to 72 holes per ferrule. The most common type of mpo-ferrule is the 12-hole type, which can provide up to 72 fiber connections in one mated pair. These are available in both multimode and singlemode versions and can be used with either standard or ELITE performance.

An MT ferrule has a square end-face that measures 6.4×2.5 mpo-ferrule mm and has a 0.25mm pitch between adjacent fiber holes. It uses a precision-molded alignment structure to ensure accurate mating. In addition, the MT ferrule is designed with tight tolerance stainless steel guide pins to minimize the amount of debris that can fall into the mating hole during operation.

The MT ferrule is most commonly found in MPO and MTP connectors, which are used to connect high-density multi-fiber cables such as 100-Gig modules. The MT connector has two components: the MT ferrule and the MT connector housing. The MT connector housing is available in a variety of colors which help to identify the mode and quality of the cable, such as beige, black, aqua or magenta for multimode and green for single-mode.

Material

MT ferrule is one of the most popular optical fiber connector types. Its square end-face is typically 12 fibers wide and holds and aligns multiple optical fibers in a single connector, which helps to increase the port density of high-speed data networks. MT ferrules are available in various configurations and colors to meet specific cabling requirements. MT connectors are also easy to use, with a simple push-pull latching mechanism that provides an audible click upon connection. These connectors can accommodate up to 72 fibers per mated pair, which makes them a good choice for high-speed applications that require a large number of ports.

Another characteristic that distinguishes MT ferrules from other types of connectors is their floating ferrule design, which improves mechanical performance. The floating ferrule allows two mated ferrules to maintain physical contact over time, even under an applied load. The float feature is especially important when connecting high-bandwidth parallel optical Tx/Rx cables, which are often used in telecommunications and data centers.

MT ferrules are typically made from thermoplastic materials that can withstand the same environmental conditions as ceramic ferrules. They are also compatible with the same cleaning procedures as ceramic ferrules, including lint-free wipes and swabs, compressed air, isopropyl alcohol, and other cleaners. Moreover, they are much less likely to get scratched or damaged than other types of connectors, making them an excellent choice for high-density cable systems.

Alignment

MPO connectors are designed to mate multiple fibers per-connection, increasing the number of ports for high-density connectivity. The key to their mechanical performance is the MT ferrule, also known as a polyphenylene sulfide (PPS) ferrule. This square-end-face ferrule features holes for multiple fibers and a standardized spacing between adjacent ones (pitch). Two stainless steel guide pins are molded into the MT ferrule to align with a mating ferrule.

The pins are critical to accurate alignment and prevent misconnections, but they can become damaged over time if they are subjected to excessive force. As such, many MPO connectors utilize elliptical-shaped, stainless-steel guide pins to avoid damage over time. The elliptical design also helps minimize debris that may accumulate in the pin holes and on the ferule end face over time.

Another improvement to MPO ferrules has been the floating design, which allows two Network Server mated ferrules to maintain physical contact even while under load or strain. This improves mechanical performance and is especially important for high-speed applications like 100 Gig modules.

Another way to identify an MPO connector is by its gender, which can be identified by the two pins protruding from the end of the ferrule. The first pin indicates a male connector, while the second indicates a female. Using the correct gender is important when connecting MPO connectors, as incorrect connections can cause severe data loss and downtime.

Applications

As networks were tasked with transmitting more and more data, the industry moved toward cabling and connectivity that included multiple fibers to reduce signal loss. These higher density systems allowed a larger number of “lanes” to be used on one cable, resulting in increased capacity and faster transmission speeds. But the high-fiber count also brought challenges for installation and testing.

To solve these challenges, MPO connectors were developed to house multiple optical fibers in a single ferrule. MPO connectors are now commonly found in 10G, 40G and 100G applications. These connectors are useful for future-proofing a network by promoting well-organized cabling and providing an efficient means to upgrade from 10G to 40G or even 100G and 400G without rewiring the entire network.

The MPO connector consists of a precision-molded MT ferrule that holds up to 24 optical fibers. It features a square end-face, with a 0.25mm pitch between adjacent fiber holes, and stainless steel guide pins that fit into precisely molded alignment holes. These pins help ensure proper alignment of the two connectors during mating. The MPO connectors are also designed to prevent guide pin loss by using a guide pin retaining clip. In addition, the insertion of a sleeve into the ferrule creates axial pressure on the sleeve, which is then pushed by a spring mounted on the outer frame sleeve to lock in place.