Optical Characteristics
Of all the differences between multimode & singlemode fiber, the most fundamental differences are the
size of the fiber’s core and the associated attenuation or loss and bandwidth of the fiber. The smaller the
core diameter, the higher the fiber’s bandwidth and the lower the attenuation (loss in dB per kilometer).
The fiber’s attenuation and bandwidth are also dependent on wavelength.
Singlemode was for high-speed long-distance transmission and multimode (in either the 50 µm or 62.5 µm
core diameters) was used for lower speed short distance applications. Multimode 50 µm fiber had a lower
cost and higher modal bandwidth than multimode 62.5 µm core fiber. Bandwidth is a measurement of the
data-carrying capacity of the fiber. A higher bandwidth fiber carries more data. See table below.
| Fiber Type | Max. Attenuation (dB/km) | Min.Overfill Launch Bandwidth (Mhz.km) | Min.Gigabit Ethernet Link Distance (m) | ||||||
| Gigabit | 10Gigabit | ||||||||
| 850nm | 1300nm | 1310nm | 1550nm | 850nm | 1300nm | 850nm | 1300nm | 850nnm | |
| OM1 62.5/125µm | ≤2.7 | ≤0.6 | – | – | ≥500 | ≥600 | 275 | 550 | – |
| OM2 50/125µm | ≤2.3 | ≤0.6 | – | – | ≥500 | ≥500 | 750 | 600 | 150 |
| OM3 50/125µm | ≤2.3 | ≤0.6 | – | – | ≥1500 | ≥500 | 1000 | 600 | 300 |
| OM4 50/125µm | ≤2.3 | ≤0.6 | – | – | ≥3500 | ≥500 | 1100 | 600 | 550 |
| G652D 9/125µm | – | – | ≤0.30 | ≤0.18 | – | – | – | – | – |
| G657A 9/125µm | – | – | ≤0.35 | ≤0.21 | – | – | – | – | – |
ANSI/TIA/EIA-598-B Standard Fiber Color Code
| Fiber Number | Fiber Color | Fiber Number | Fiber Color |
| Fiber 1 | Blue | Fiber 7 | Red |
| Fiber 2 | Orange | Fiber 8 | Black |
| Fiber 3 | Green | Fiber 9 | Yellow |
| Fiber 4 | Brown | Fiber 10 | Purple |
| Fiber 5 | Gray | Fiber 11 | Pink |
| Fiber 6 | White | Fiber 12 | Aqua |
| Fiber 13 and higher The color code is repeated with added black stripe or dash | |||
| Note: Fiber Tube color will be followed with same order. | |||
