Communication has become more and more important in our lives. The world's social, economic and political system is dependent upon its ability to communicate and transmit both voice and data information. Networks of optical fiber connector continents and circle the globe making this communication possible. Fiber optic connectors comprise of a ferrule, connector body, cable and coupling device. The end of the fiber is mounted on the end of ferrule. It is bored through the center thus cladding the fiber. This often induces scratches on the fiber. Some types of fiber optic connectors are FC, MTP, SC, and ST. FC fiber optic connector is used for testing environments and mostly for single mode applications. FC stands for "Fixed Connection". It was the earliest connector and is now available in FC PC, FC APC, FC SPC and FC UPC types. It was originally devised by NTT (Nippon Telegraph and Telephone) for telecommunication applications. Thus it is popular in Japan and Europe. In the US, MCI used it in its fiber optic telephone networks in 1980s. FC connector has a threaded coupling mechanism with adjustable keying to achieve minimum insertion loss. You can adjust the key in some degree in order to lock it at the minimum loss position. Although this tuning is useful in some applications where minimum loss is required, it is not used in most applications because of the small gain of 0.1~0.2dB in insertion loss. SC stands for "Subscriber Connector" or "Square Connector", which was developed by NTT. SC connector has a push-pull locking mechanism which is very flexible yet provides high repeatability and low insertion loss. It has been quickly replacing legacy connectors such as ST, SMA connectors and becoming the current most popular fiber connectors used in the fiber optic communication industry. MTP stands for "Multifiber Termination Push-on" connector and it is designed by USConec and built around the MT ferrule. Each MTP is smaller than most duplex connections in use today because it contains 12 fibers or 6 duplex channels in a connector. It is designed as a high-performance version of the MPO and will interconnect with MPO connectors. ST connector stands for "Straight Tip". It was developed by AT&T and is a registered trademark of AT&T. The formal name as defined in ISO/IEC standards is BFOC/2.5. ST connector was the first most popular and thus defactor standard connector in the fiber optic communication industry. It evolved from copper cable connector designs using a half-twist bayonet lock mechanism and has a plug and socket. ST connector is standardized in EIA/TIA-604-02 chapter FOCIS 2.