In multi-mode fiber system, numerous modes or light rays are carried simultaneously through the waveguide. Multi-mode fiber systems offer flexible, reliable and cost effective cabling solutions for local area networks (LANs), storage area networks (SANs), central offices and data centers.
Multi-mode fibers are identified by the OM (“optical mode”) designation as outlined in the ISO/IEC 11801 standard. Today there are four types of multi-mode fiber: OM1 (62.5μm multi-mode fiber), OM2 (50μm multi-mode fiber), OM3 (laser optimized 50μm multi-mode fiber), OM4 (laser optimized 50μm multi-mode fiber). 62.5μm and 50μm mean the diameters of the glass or plastic core, the part of the fiber carrying the light which encodes the data. These different multi-mode fiber cables can support data rates from 10 and 100 Megabits per second (Mb/s) up to 1 Gigabit per second (Gb/s) and 10 Gb/s, even up to 40 Gb/s and 100 Gb/s.
62.5 μm multi-mode fiber (OM1) was introduced in 1985. OM1 fiber could support 2km campuses at 10 Mb/s. For more than a decade, 50μm multi-mode fiber (OM2) was established for both short and long distance applications with the data rates range from 10 Mb/s to 100 Mb/s.
As the need for higher data rates and longer distance increases, new transmission media must be made to meet the requirements. Thus the laser optimized multi-mode fiber cables, that is, OM3 and OM4 cables which could support higher data rates about 1Gb/s, 10Gb/s, even about 40Gb/s and 100Gb/s over longer distances than OM1 and OM2 cables are introduced.
OM3 fiber cable has a higher bandwidth to support 1 Gb/s and 10 Gb/s over longer distance. But compared with the installation cost of networks using lower bandwidth OM1 or OM2 fibers, OM3 is cost effective and saves for the electronics when upgrading to higher speeds. Besides, OM3 fiber cables share the same connector and installation techniques as 62.5 µm fiber. So the installers don’t need additional training, which will increase the cost. As a result, OM3 will be a good choice for customers in LANs, SANs, and data centers.
Like OM3, OM4 is also laser optimized multi-mode fiber with extended bandwidth. It’s designed for existing 1 and 10 Gb/s applications as well as future 40 and 100 Gb/s systems by 850nm Vertical Cavity Surface Emitting Lasers (VCSELs). Although OM2 fiber can use VCSELs, it can only reach 550 meters at 1 Gb/s and 82 meters at 10 Gb/s. While OM4 can transmit the data over 1000 meters at 1 Gb/s and 550 meters at 10 Gb/s. With its high bandwidth, OM4 will be the best solution for network designers and operators in data centers and LANs.
The booming network technology drives the need for increased data rates and fiber usage in the data center. High density optical connectivity are important to optimize cable management. Because OM3 and OM4 fiber cables are good for transporting higher data rates and they are primarily applied in the data center. OM3 and OM4 fibers continue to be improved to meet new challenges.