Standardization in fiber optic industry is one of the most confusing areas for people who involved in the business. “OM” terminology in fiber optic technology is new to both users and fiber optic manufacturers. The letters “OM” stand for optical multi-mode, which is marked multi-mode optical fiber specifications. There are four standards in fiber optic terminology: OM1, OM2, OM3, OM4. This post is going to illustrate what they are.

According to ISO 11801 standard, multi-mode fiber cables are described using a system of classification determined by OM1, OM2, and OM3. OM4 is a laser-optimized, high bandwidth 50µm multi-mode fiber. In August of 2009, TIA/EIA approved and released 492AAAD, which defines the performance criteria for this grade of optical fiber. While they developed the original “OM” designations, IEC has not yet released an approved equivalent standard that will eventually be documented as fiber type A1a.3 in IEC 60793-2-10.

OM1 cable typically comes with an orange jacket and has a core size of 62.5 micrometers (µm). It can support 10 Gigabit Ethernet at lengths up 33 meters. It is most commonly used for 100 Megabit Ethernet applications.

OM2 also has a suggested jacket color of orange. Its core size is 50µm instead of 62.5µm. It supports 10 Gigabit Ethernet at lengths up to 82 meters but is more commonly used for 1 Gigabit Ethernet applications.

OM3 has a suggested jacket color of aqua. Like OM2, its core size is 50µm, but the cable is optimized for laser based equipment that uses fewer modes of light. As a result of this optimization, it is capable of running 10 Gigabit Ethernet at lengths up to 300 meters. Since its inception, production techniques have improved the overall capabilities of OM3 to enable its use with 40 Gigabit and 100 Gigabit Ethernet up to 100 meters. 10 Gigabit Ethernet is its most common use.

OM4 also has a suggested jacket color of aqua. It is a further improvement to OM3. It uses a 50µm core but supports 10 Gigabit Ethernet at lengths up 550 meters and it supports 100 Gigabit Ethernet at lengths up to 150 meters.

Higher bandwidth requirements have accelerated 40 and 100 Gb/s applications. OM4 effectively provides an additional layer of performance that supports these applications at longer distances, thereby limiting the number of installations truly require OS2 single-mode fiber. OM4 can provide a minimum reach of 125m over multi-mode fiber within the 40 and 100 GbE standards.

Standardization of OM used not only for fiber optic cables but also fiber patch cables. Multi-mode 50 125 duplex fiber patch cable LC-LC provides 10 gigabit data transfer speeds in high bandwidth applications via 50/125µm laser-optimized OM4 fiber. They are 5 times faster than standard 50um fiber cable and work with both VCSEL laser and LED sources.