Multimode fibers are identified by the OM (“optical multimode”) designation as outlined in the ISO/IEC 11801 standard.
OM1, for fiber with 200/500MHz*km overfilled launch (OFL) bandwidth at 850/1300nm (typically 62.5/125um fiber)
OM2, Type A1a.1, for fiber with 500/500MHz*km OFL bandwidth at 850/1300nm (typically 50/125um fiber)
OM3, Type A1a.2, for laser-optimized 50um fiber having 2GHz*km effective modal bandwidth (EMB, also known as laser bandwidth), designed for 10 Gb/s transmission.
OM4, Type A1a.3, for laser-optimized 50um fiber having 4.7GHz*km EMB bandwidth designed for 10 Gb/s, 40 Gb/s, and 100 Gb/s transmission.
OM3 vs OM4
OM4 fiber has been on the market since 2005, sold as premium OM3 or OM3 fiber. The OM4 designation standardizes the nomenclature across all manufacturers so that the customer has a clearer idea of the product that they are buying. OM4 is completely backwards compatible with OM3 fiber and shares the same distinctive aqua jacket. OM4 was developed specifically for VSCEL laser transmission and allows 10 Gig / second link distances of up to 550 Meters (compared to 300M with OM3).
The effective modal bandwidth for OM4 is more than double that of OM3 (4700 MHz.km for OM4 v/s 2000 MHz.km for OM3).
While OM3 fiber will still be future proof in most applications, allowing speeds of 10GB/s up to 100GB/s, OM4 fiber offers users longer length distances and more wiggle room in optical budgets
At Cables Plus, we feel that offering our customers a high quality product is our first priority. In order to allow our stocked product to fill the widest possible set of standards, we have begun moving to an OM4 product line. While we are still able to supply the OM3 fiber patch cables you have become accustomed to over the last 5 years, Cables Plus is moving to standardize on OM4 patch cables for stocking. We feel that this offers our customers with the highest quality product on the market while still maintaining at our low cost solution.
OM5, for laser-optimized 50um fiber greate than 28GHz*km EMB bandwidth designed for 40 Gb/s, and 100 Gb/s transmission.
