Transmission distance of four-core multimode fiber

A four-core multimode fiber can typically transmit data over distances ranging from 33 meters to 400 meters, depending on fiber type, data rate, and light source.Key Factors Affecting Distance

Multimode fiber (MMF) carries multiple light modes simultaneously, which makes it ideal for high-bandwidth, short- to medium-range applications such as LANs and data centers . The core diameter (50–62.5 µm) and the type of light source—LED or VCSEL—significantly influence the maximum transmission distance . Modal dispersion, where different light modes arrive at slightly different times, is the primary limitation for MMF distance .

Typical Distance by Fiber Type and Data Rate

• OM1 (62.5 µm core, LED): Supports 1 Gbps up to 275 meters and 10 Gbps up to 33 meters .
• OM2 (50 µm core, LED): Supports 1 Gbps up to 550 meters and 10 Gbps up to 82 meters .
• OM3 (50 µm core, laser-optimized, VCSEL): Supports 10 Gbps up to 300 meters, 40 Gbps up to 100 meters, and 100 Gbps up to 100–150 meters .
• OM4 (50 µm core, laser-optimized, VCSEL): Supports 10 Gbps up to 400 meters, 40 Gbps up to 150 meters, and 100 Gbps up to 150 meters .
• OM5 (50 µm core, wideband multimode): Supports 40 Gbps up to 150 meters and 100 Gbps up to 100 meters, with wavelength-division multiplexing (WDM) enabling higher capacity .

Practical Considerations

• Four-core configuration: The number of cores does not directly affect the maximum distance per core; each core behaves like a standard multimode fiber strand.
• Installation quality: Connectors, splices, and bends can reduce effective distance due to additional loss .
• Light source: VCSEL lasers extend distance compared to LEDs due to narrower spectral width and reduced modal dispersion .

Summary

For a four-core multimode fiber, the achievable transmission distance depends on the fiber type and data rate:

• Short-range, low-speed (1 Gbps): Up to 550 meters (OM2).
• Medium-speed (10 Gbps): 33–400 meters (OM1–OM4).
• High-speed (40–100 Gbps): 100–150 meters (OM3–OM5). Choosing the appropriate fiber type and light source is crucial for optimizing performance in data centers or enterprise networks .