Identify the connector type of the cables you want to connect. A fiber optic adapter, also known as a fiber coupler, is a passive device used to connect and align two optical fiber connectors. It enables optical signals to pass from one fiber to another with minimal loss, ensuring stable and reliable communication. In this tutorial. There are many types of fiber optic connectors, including SC, LC, FC, ST, D4, MU, MT/MPO, etc. To learn more about the types of fiber optic connectors, click here: Types. Proper connection of fiber optic cables is essential to harness these benefits fully, as even minor errors can lead to significant performance issues like signal loss.