Each connector differs in ferrule size, coupling mechanism, insertion loss behavior, handling convenience, and suitability for specific environments such as FTTH, data centers, industrial networks, and legacy systems. Of the more than a dozen types of fibre-optic connectors available, the four most commonly used today are LC, SC, FC, and ST. In this guide, we break down the most common optical fiber. Optical fiber connectors are the physical interface of light-based communication, ensuring precise alignment between fiber cores for minimal signal loss.