Single-mode fiber carries a single light path, resulting in low loss, long transmission distance, and higher bandwidth. In fiber optic networking, one of the most common questions is whether to use single-mode or multimode fiber between switches. Although they can do the same job in some instances, the different construction methods make each of them better suited to certain tasks and budgets. This guide breaks down the technical differences and practical applications of each fiber type. </p> <h2>Core Difference: Light Propagation</h2> <p>The fundamental distinction. OS1 single mode fiber optic cables are made with a single mode fiber core, which means that they have a very small core diameter of 9 microns.