OM5 Multimode Fiber is the latest generation of multimode optical fiber, optimized for wideband transmission and high-speed data transfer, ideal for short-distance, high-density scenarios like modern data centers. What is OM5 Multimode Fiber? OM5 is a multimode fiber (MMF) standard defined by the International Electrotechnical Commission (IEC). It features a 50/125 μm core/cladding diameter (50μm core for light transmission, 125μm cladding for total internal reflection). Unlike previous OM3/OM4 fibers, OM5 is a “wideband multimode fiber” (WBMMF) designed to support multiple wavelength bands (850nm, 880nm, 910nm, 940nm), enabling higher bandwidth and longer transmission distances for short-haul links.