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February 12, 2018

Multimode (OM1, OM2, OM3, OM4, OM5) and Single Mode (OS1, OS2) Fiber

What are OM and OS type fiber optic cables?
In ANSI/TIA-568.3-D, the TIA adopted the nomenclature for fiber found in the international standard ISO/IEC 11801. The multimode fiber is prefixed with “OM” and the singlemode mode “OS”.

The new designation in ANSI/TIA-568.3-D should alleviate some of the confusion associated with application support distance issues. Each “OM” has a minimum Modal Bandwidth (MBW) requirement.

Bandwidth and attenuation comparison between different OM fiber optic cables

Multimode Fiber Overfilled launch bandwidth (MHz.km) Laser Launch Attenuations (dB/km)
Fiber Type TIA Fiber Standard Core diameter (um) 850 nm 1300 nm 850 nm 850nm 1300nm
OM1 492-AAAA 62.5 200 500 Not specified 3.5 1.5
OM2 492-AAAB 50 500 500 Not specified 3.5 1.5
OM3 492-AAAC 50 1500 500 2,000 2.3 0.6
OM4 492-AAAD 50 3500 500 4,700 2.3 0.6
OM5 492-AAAE 50 3500 500 4,700 2.4 0.6

Attenuation refered to YOFC Multimode Fiber.

Maximum channel length comparison between different OM fiber optic cables

 Fiber Mode 100BASE 1000BASE 10GBASE 40GBASE 100GBASE
850nm 1300nm 850nm 1300nm
OM1 up to 2000m 275m 550m 33m up to 300m Not specified Not specified
OM2 up to 2000m 550m 550m 82m up to 300m Not specified Not specified
OM3 up to 2000m 550m 550m 300m up to 300m 100m 100m
OM4 up to 2000m 1000m 550m 550m 400m* 150m 150m
OM5 up to 2000m Not specified Not specified Not specified 400m* 150m 150m

Attenuation comparison between different OS fiber optic cables

  1310 nm 1383nm 1550 nm
OS1(EN50173-1:Ed.2: 2010) 1.0 dB/km 1.0 dB/km 1.0 dB/km
OS2(EN50173-1:Ed.2: 2010) 0.4 dB/km 0.4 dB/km 0.4 dB/km
OS1(ISO/IEC11801Ed.2.2:2010) 1.0 dB/km Not specified 1.0 dB/km
OS2(ISO/IEC11801Ed.2.2: 2010) 0.4 dB/km 0.4 dB/km 0.4 dB/km
OS2(ISO/IEC24702: 2006) 0.4 dB/km 0.4 dB/km 0.4 dB/km

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