Cable assemblies are cables pre-terminated at the manufacturing plant with connectors at either one or both ends, and with one or multiple fibers inside.

When the cable carries only one optical fiber inside, it is called “pigtail” if only one end is pre-connectorised, and “patchcord” or “jumper” if both ends are pre-connectorised.

If we have more than one fiber in the cable, we will call “trunk” when both ends are pre-terminated with the same number of connectors, or “harness” if we transition from one multifibre connector to multiple single fiber connectors.

Each of the three components of a cable assembly (optical fiber, cable design and type of connector) equally matters when choosing the right product for a given application. Which one to choose among the variety of options we offer will depend on the equipment that the assembly will be plugged into as well as the specific requirements of the environment where it will be installed.

Central office and Data Centers have similar requirements as in fact they are merging now with central offices redesigned into data centers. In these environments density of connectors, small cable diameters and matching the cable assembly with the hardware are very important aspects to consider.

In FTTH deployments pre-assembled distribution and drop cables can speed up network deployment and lower installation costs. In terms of deployment speed, micro cables are very popular as they can easily cover hundreds of meters using blowing techniques. This is an environment very exposed to bends though, so bend insensitive fibers play also an important role in these application space.

In mobile sites where cable assemblies are heavily exposed to the elements, strong cable jackets can be become critical to ensure that the link can withstand the adverse climatology and/or the attack of birds and rodents. It is also typical  in this scenario the use of bend insensitive fibers to protect the link from undesired bends that could cause signal loss.

LC, SC, FC and ST are the acronyms that refer to four of the most popular types of connectors.

FC stands for “ferrule connector” and it was the first optical connector that featured a ceramic ferrule. Developed in Japan, the screwed fitting of this connector makes it vibration-proof therefore very useful on scenarios where there is motion or where precission is paramount (e.g. OTDR measurements). They are also very popular in CATV neworks. Although it was the first using ceramic ferrules, the use of FC connectors is less widespread than SC and LC connectors.

With half the size than SC or ST connectors, Lucent Connectors (LC), developed by Lucent Technologies in 1997, are frequently used in high-density applications where space matters. They come with push-and-pull fitting making them safer and more compact than the SC-type. These connectors are often required for SFP (small form-factorable pluggable) modules and widely deployed in racks and panels.

Straight Tip (ST) connectors are similar in shape to the FC, except for its bayonet style fitting. It was developed by AT&T™ in the US and it is used in professional environments like corporate networks and even military field. -designed connector.

Suscriptor Connectors (SC) were developed by Nippon Telegraph and Telephone becoming nowadays the most popular connector in the optical industry because of its low production costs. It also features a quick push-and-pull fitting, and it s is compact in its design allowing a good density of connectors for FTTH and CATV networks.

The PC/UPC/APC terminology refers to the type of polishing applied to the ceramic ferrule that hosts the optical fiber inside.

• PC stands for Physical Contact and in this polishing type the ferrule is levelled and finished in a plain surface to avoid empty spaces between two ferrules coupled. The insertion loss for this type of polishing is between -30 dB and -40 dB and it is no longer used.

• UPC stands for Ultra Physical contact and in this polishing type the ferrule is levelled and finished in a sharper curve of the bevel allowing lower return losses between -40 and -55 dB.

• APC is the most used polishing type and it stands for Angled Physical Contact. In this case the ferrule ends in a plain, 8 degree-angled surface allowing the connectors to achieve a better coupling, lowering return losses below -60 dB.