Introduction to knowledge of multimode optical fiber
Compared with single mode fiber, multimode fiber is easier to remember, mainly OM1、OM2、OM3、OM4、OM5.OM：stand for optical multi-mode,, that is, optical mode, is the standard of multimode fiber for fiber grade. The bandwidth and maximum distance of different levels of transmission are different. Brief introduction:
OM1 refers to 50 um or 62.5 core diameter multimode fiber with full injection bandwidth above 200/500 MHz.km. Core size :62.5 um; data rate :1:300 m; Application: building interior, short range network, local area network (LAN) and special network.
OM2 means 50 um or 62.5 core diameter multimode fiber with full injection bandwidth of 500/500 um 850/1300; The core diameter and numerical aperture are small, effectively reducing the mode dispersion of multimode fiber, To significantly increase the bandwidth, Production costs were also reduced by one third; Core size :50 um; Data rate :1 GB@850nm; Distance: up to 600 meters, Usually for shorter distances, 2 times the distance capacity of the OM1; Application: Inside the building, Short - range networks, LAN (LAN) and dedicated network.
[OM3]( Laser Optimization)
OM3 is a 50 um core diameter multimode fiber optimized by 850 laser, Of the 10 Ethernet nm VCSEL Gb/s 850, Fiber optic transmission distance up to 300 m; Flame retardant skin, Can prevent the spread of flame, prevent the emission of smoke, acid gas, gas, etc., and meet the needs of 10 gb/s transmission rate; Core size :50 um; Date rate :10 GB@850nm; Distance :300 meters, Use MPO connectors to run 40 GB or 100 to 100 meters; Applications: larger dedicated networks, Such as data center wiring.
The effective bandwidth ratio OM3 more than twice that developed for VSCEL laser transmission. Core size :50 um; data rate :10 GB@850nm; distance :550 meters, using MPO connectors can run 100 to 150 meters; applications: high speed network / data center, financial center and enterprise park.
OM5 is the current multi-mode optical fiber category more concentrated in one category, compared with the previous four, obviously OM5 superior technology.
(1) Fewer fibers support higher bandwidth. The working wavelength of the OM5 fiber jumper is 850/1300 nm, and can support at least 4 wavelengths. The usual operating wavelengths of OM3 and OM4 are 850 nm and 1300 nm.. The That is to say, the traditional OM1、OM2、OM3、OM4 multimode fiber has only one channel, while the OM5 has four channels, and the transmission capacity is increased by four times.
(2) Lower fiber loss. The attenuation of OM5 broadband multimode cable is reduced from 3.5 dB/km of the previous OM3,OM4 cable to 3.0 dB/km, and the bandwidth requirement on the wavelength of 953 is increased.
(3) Better compatibility. OM5 have the same fiber size as the OM3,OM4, which means that it is fully compatible with the OM3,OM4, if you want to apply OM5, on the existing wiring is not required to change. The future OM5 will also be widely used in 100 G/400G/1T of super-large data centers.