OM1 Multimode Fiber Transmission Distance

OM1 multimode fiber supports up to 275 meters at 1 Gbps and 33 meters at 10 Gbps.

OM1 is the earliest standardized multimode fiber, featuring a 62.5 µm core diameter and an orange jacket for easy identification. It typically uses LED light sources and operates at 850 nm and 1300 nm wavelengths, making it suitable for short-distance, low-speed Ethernet applications within buildings or small LANs (EDGE Optical, Wolontek, Weunion) .

Transmission Distances by Data Rate

• 100 Megabit Ethernet (Fast Ethernet): OM1 can easily support standard distances up to 300 meters, making it suitable for legacy LAN setups .
• 1 Gigabit Ethernet (Gigabit Ethernet): Maximum distance is approximately 275 meters at 850 nm with LED sources .
• 10 Gigabit Ethernet (10GBASE-SR): OM1 is limited to 33 meters, due to modal dispersion and lower bandwidth (200 MHz·km) .

Key Characteristics

• Core Size: 62.5 µm
• Bandwidth: 200 MHz·km at 850 nm
• Light Source: LED
• Jacket Color: Orange
• Typical Applications: Short-range LANs, legacy network upgrades, and intra-building connections .

Practical Considerations

OM1 fiber is largely phased out in modern high-speed networks because it cannot support 10G Ethernet over practical distances. For new installations, OM3 or OM4 fibers are recommended, as they support longer distances and higher data rates using VCSEL lasers. OM1 is still relevant for upgrading or maintaining older infrastructure where 1 Gbps or lower speeds are sufficient . In summary, OM1 multimode fiber is suitable for short-distance, low-speed applications, with a maximum practical transmission distance of 275 meters at 1 Gbps and 33 meters at 10 Gbps, making it ideal for legacy LANs but not for modern high-speed data center deployments.