OM2 is a 50 µm multimode fiber optimized for LED sources and short-distance 1G/10G Ethernet, while OM3 is a laser-optimized 50 µm multimode fiber designed for higher-speed 10G, 40G, and 100G Ethernet over longer distances.

OM2 Fiber

OM2 is a multimode fiber standardized in 1998 with a 50 µm core diameter and an orange jacket. It typically uses LED light sources, which limits its bandwidth and distance capabilities compared to laser-optimized fibers. OM2 is commonly used for 1 Gigabit Ethernet over distances up to 550 meters, and can support 10 Gigabit Ethernet over shorter distances, around 33–82 meters depending on hardware and conditions. Its modal bandwidth is approximately 500 MHz·km, making it suitable for older or lower-speed network infrastructures .

OM3 Fiber

OM3 was standardized in 2003 and is a laser-optimized 50 µm multimode fiber with an aqua-colored jacket. Unlike OM2, OM3 is designed for VCSEL (Vertical-Cavity Surface-Emitting Laser) sources, which allow higher-speed data transmission. OM3 supports 10 Gigabit Ethernet up to 300 meters, and can also handle 40G and 100G Ethernet up to 100 meters. Its modal bandwidth is significantly higher at 2000 MHz·km, making it ideal for modern enterprise networks and data centers where higher-speed and longer-distance multimode transmission is required .

Key Differences Between OM2 and OM3

Summary

OM2 and OM3 are both 50 µm multimode fibers, but OM3 is laser-optimized for higher-speed applications and longer distances, while OM2 is LED-based and suitable for lower-speed, shorter-distance networks. Choosing between them depends on the required data rate, distance, and network infrastructure. OM3 is generally preferred for modern high-speed networks, whereas OM2 may still be found in legacy installations .