What Is OM3 Fiber?

Since the internet spread out across the globe, the aim of fiber to the building or home has been achieved through the installation of optical fibers. Besides, with the features of huge capacity, board transmission bandwidth and powerful resisting jam ability, there is no doubt that optical fibers have been the preferred transfer media of gigabit ethernet. OM3 fiber is one of the mainstream market optical fibers.

The Emergence of OM3 Fiber

OM3 fiber is a kind of multimode fiber which is usually applied in short distance. In data communication segment, multimode fibers are divided into several categories, OM1, OM2, OM3 and OM4.

The earlier fibers, OM1 fiber has a core size of 62.5 micrometers while OM2 fiber features with a smaller core size of 50 micrometers. They are generally applied in premises applications supporting ethernet rates of 10 Mbps to 1 Gbps. The two types are ideal for use with LED transmitters due to their relatively large core size. However, as the increasing demand for bandwidth and higher throughput, especially along came the 10 Gigabit Ethernet, LEDs could not keep pace for they can not be turned on and off fast enough to support higher-speed applications. In response, the data communication industry begun to develop a high-speed laser light source called a vertical cavity surface-emitting laser (VCSEL). LEDs typically support a maximum modulation rate of only a few hundred Mbit/s, but VCSELs can handle the modulation rate up to 10Gbit/s. As a result, OM3 fiber was born, which commonly refers to as “laser optimized multimode fiber”. OM3 fiber is designed for 10Gigabit Ethernet at lengths up to 300 meters.

OM3 fiber

OM3 Fiber vs OM4 Fiber

Fibers of OM3 and OM4 are both laser optimized 50/125 multimode fiber that are produced to accommodate today’s higher speed networks. This  means their core diameter is 50µm and the cladding diameter is 125µm. Compared with other multimode fibers, these two share a special coating that can prevent light from escaping the core. In addition, OM3 and OM4 are optimized for 850nm transmission and have aqua sheaths. The technology of OM3 and OM4 make it possible that the designs of laser transmission system can utilize multimode optical fiber without the use of mode conditioning cables.

With so many similarities, there are still some differences between OM3 fiber and OM4 fiber.

  • Transmission Distance

The main difference between OM3 and OM4 is the transmission distance because they have different internal constructions. OM4 employs a higher modal bandwidth of 4700 MHz/km while the modal bandwidth of OM3 is 2000 MHz/km, which means OM4 can carry more data or information within the same distance.

  • OM3 Enjoys a Price Advantage

As mentioned above, because of different constructions, the primary cost of OM4 rises. The price of OM4 is double that of OM3 fiber’s due to its manufacture technique and market fluctuations. In addition, considering that 90% data centers have their runs under 100 meters, OM3 may be a better choice for money saving.


At present, OM3 fiber has successfully made contributions to the implementation of today’s higher speed network. And with good performance like high data rate and lower price, it has become a must for data center upgrade. At FS.COM, the comprehensive range of products in OM3 fiber offer customers the ability to create the optimal network.