Single fiber modules (BiDi) use one fiber for both transmitting and receiving data. Whether you're designing a short-range data center network or a long-distance metro backbone, understanding the distinctions between single vs. This guide breaks down these two critical dimensions of optical transceiver design to help. There are two main types of fiber optic cables: single mode and multimode. That makes picking between single mode and multimode fiber optic cables an. But not all fiber cables are created equal: multimode (MM) and single mode (SM) fibers are the two primary types, each engineered for specific use cases, from short-range data center connections to transcontinental telecom backbones. multimode refers to the type of fiber core and how. Should you use a single strand (BiDi) or two strands? Do converters need to be used in pairs? Can you mix brands? What wavelengths matter? This guide answers it all with clear diagrams, step-by-step checklists, and field-tested troubleshooting tips.