A fiber optic connector (optical fiber connector) is a small glass or plastic device that is placed at the end of a fiber optic cable in order to allow light from the cable to enter another device. Fiber optic connectors are often spring-loaded and align the core of each fiber so that they are all directly touching the receiver. This allows light to be contained within the fiber optic cable rather than being let out into the air, in which case data would be lost. While fiber optic connectors are generally pre-assembled onto fibers at the manufacturing facility, they can also be installed on the field.

How Fiber Optic Connectors Work
A fiber optic connector consists of an adapter and two connector ports so that two separate fiber optic cables can be connected to it. Fiber optic connectors can be made for both temporary and permanent applications. Permanent applications require a splice. Generally, the fiber cores are made of the same material, whether it be glass, plastic, or another transparent material. Although many different types of fiber optic connectors have been introduced to the market in the past forty years, every fiber optic connector has some mechanism for coupling the optical fibers.

Applications
Fiber optic connectors can be used to join two or more fiber optic cables together, connect a fiber optic cable to testing equipment for analysis, and connect various types of equipment at telephone companies. Fiber optic connectors are used underground, on utility poles, or on outside walls, and are therefore sometimes enclosed to prevent damage from water, insects, and even germs. While hermetic (closed) enclosures leave the fiber optic connector vulnerable to temperature changes, they eliminate the risk of damage from humidity. On the other hand, free-breathing (porous) enclosures leave the fiber optic connector vulnerable to humidity, temperature changes, condensation, and biological threats.

Advantages
Fiber optic connectors are not only advantageous, but required to make a connection between two systems using fiber optic cables. Fiber optic cables are usually very sturdy and can be connected/disconnected between 500 and 1,000 times before they must be replaced. Technical-grade and military-grade fiber optic connectors are usually built to be more resistant to corrosion, extreme temperatures, humidity, radiation, and other environmental conditions. They are also built tensilely in order to reduce cracking and/or loose connections.

Disadvantages
Fiber optic connectors are available in many different models. Each model works with a specific type of fiber optic cable. This makes it even more important for the user to be sure of the type of fiber optic cable he/she is working with in order to make a compatible connection. Fiber optic cables must also be installed properly to ensure that fiber optic cores line up with each other and allow light to pass through them.