To determine if your SFP (Small Form-factor Pluggable) module is single mode or multimode, you can look for specific markings or labels on the module itself. Typically, single mode SFP modules are labeled as "SM" or "single mode," while multimode modules may be labeled as "MM" or "multimode. ". 12 MM50: This refers to a 12-strand Multimode (MM) fiber cable with a 50-micron core size. Multimode Fiber (MMF) has a core diameter, typically 50–100 micrometers, has ability to transfer multiple modes of light through the fiber core, uses lower-cost electronics (LED, VCSEL) operates at. In optical communication systems, the choice between single mode (SM) and multimode (MM) fiber hinges on performance requirements, distance, and budget. 2-core o In optical modules, "core".