850nm multimode fiber typically supports distances from tens of meters up to 550 meters depending on fiber type and data rate.

Transmission Distances by Fiber Type and Data Rate

• OM1 (62.5 µm core): Supports 1 Gbps up to 275 meters and 10 Gbps up to 33 meters at 850nm, using LED sources .
• OM2 (50 µm core): Supports 1 Gbps up to 550 meters and 10 Gbps up to 82 meters at 850nm .
• OM3 (50 µm laser-optimized): Supports 10 Gbps up to 300 meters and 40 Gbps up to 100 meters at 850nm .
• OM4 (50 µm laser-optimized): Extends 10 Gbps up to 550 meters, 40 Gbps up to 150 meters, and 100 Gbps up to 150 meters at 850nm .
• OM5 (wideband multimode): Designed for 850–953 nm WDM applications, supporting similar or slightly extended distances for high-speed SR4/SR8 modules .

Key Factors Affecting Distance

1. Data Rate: Higher speeds reduce maximum distance due to modal dispersion and bandwidth limitations. For example, 10G can reach hundreds of meters on OM3/OM4, but 40G/100G is limited to 100–150 meters .
2. Fiber Type: Laser-optimized fibers (OM3, OM4, OM5) allow longer distances at high data rates compared to older OM1/OM2 fibers .
3. Transceiver Technology: 850nm VCSELs are standard for short-reach multimode links, offering low power consumption and high compatibility with OM3/OM4/OM5 fibers .
4. Modal and Chromatic Dispersion: Multimode fibers support multiple propagation modes, which causes pulse spreading and limits distance, especially at higher speeds .

Practical Applications

• Data Centers: OM3 and OM4 fibers with 850nm VCSELs are widely used for 10G, 40G, and 100G short-reach interconnects. OM4 is preferred for longer intra-data center links up to 550 meters at 10G .
• LANs and Campus Networks: OM1 and OM2 fibers are suitable for lower-speed applications or short-distance connections, typically under 100 meters for 10G .
• High-Speed WDM Systems: OM5 fibers enable multiple wavelength channels over the same fiber, extending effective reach and capacity for 850nm-based systems . In summary, 850nm multimode fiber is ideal for short-reach, high-speed applications, with OM3/OM4 fibers supporting hundreds of meters at 10G and OM4/OM5 fibers extending support for 40G and 100G links. Choosing the right fiber type and transceiver combination is essential to maximize distance and performance.