Tag Archives: OM3

Optical Fiber Cable Types

In recent years, the trend that optical fiber cables are gradually replacing copper wire as the appropriate method of communication signal transmission has become obvious. They straddle the long distances between local telephone systems and provide backbone for many network systems. Besides, other system users of optical fiber cable include cable television services, university campuses, office buildings, industrial plants, and electric utility companies. Then, what are the optical fiber cable types?

Optical Fiber Cable Types

According to the light transmission mode, optical fiber cable can be classified into two types: single mode and multi mode.

Single Mode Optical Fiber Cable

Also known as single mode optical fibers, and single mode optical waveguides, the single mode optical fiber cable is a kind of single stand of fiberglass, 8.3 to 10 microns in diameter (mostly two fibers are used), which has one mode of transmission. The diameter of single mode optical fiber is relatively narrow, through which only one mode will propagate typically 1310 or 1550nm. It has higher bandwidth than multimode optical fiber, but requires light source with narrower spectral width.

Single mode fiber cable provides higher transmission speed and 50 times higher distance than multimode cable, but it also needs higher fiber optic cable price. The single mode fiber has a much smaller core than the multimode. The small core (just 9µm) and single light-wave almost eliminate any distortion caused by overlapping light pulses, providing the minimum signal attenuation and maximum transmission speed for any type of fiber cable.

single mode optical fiber cable

Figure1: Single Mode Optical Fiber Cable

Single mode cables can be classified into OS1 and OS2.

  • OS1 – OS1 is used for indoor, that is, campus, data center and so on. The wiring is tightly cushioning. Indoor fiber is more resistant to bending. It is more plastic and flexible, and the buffer cable can reduce the risk of catastrophic damage.
  • OS2 – OS2 is used for outdoor or loose tube, namely streets, underground, etc. Outdoor fibers are bend sensitive, so it is easier to break during installation, unless unless they are carefully installed.
Multimode Optical Fiber Cable

Multimode cables are slightly larger in diameter and share a common diameter in the 50-100 micron range of optical components (the most common size in the United States is 62.5 µm). Multimode fiber provides you with high bandwidth (up to 10 to 100Mbs- Gigabit to 275m to 2Km) over medium distance.

Multimode optical fibers are usually cost-effective for inside buildings or enterprise campuses, while single mode is more suitable for longer distance running. Single mode optical fiber can transmit longer distances, but usually used in expensive equipment. For devices with a length of not more than a few hundred meters, multimode is cost-effective.

multimode optical fiber cable

Figure2: Multimode Optical Fiber Cable

Multimode cables can be found in OM1, OM2, OM3 and OM4 types. Each type has its own characteristic.

  • OM1 – With a core size of 62.5 microns (µm), the OM1 cable is usually equipped with an orange jacket. It can support 10 Gigabit Ethernet at a length of 33 meters. It is most commonly used in 100 Megabit Ethernet applications.
  • OM2 – OM2 also has the orange color suggested jacket. Its core size is 50µm, not 62.5µm. It supports 10 Gigabit Ethernet, up to 82 meters in length, but it`s more commonly used for 1 Gigabit Ethernet applications.
  • OM3 – OM3 has the suggested jacket of the aqua color. Like OM2, its core size is 50µm, but cables are optimized for laser-based devices that use fewer light modes. As a result of this optimization, it can run 10 Gigabit Ethernet over a length of 300 meters. Since commissioning, production technology has improved the overall performance of OM3, enabling its use with 40 Gigabit and 100 Gigabit Ethernet up to 100 meters.
  • OM4 – OM4 also has the suggested jacket of the aqua color. This is a further improvement of OM3. OM4 also uses a 50µm core, but it supports a 10 Gigabit Ethernet at a length of 550 meters and a 100 Gigabit Ethernet at a length of up to 150 meters.

Conclusion

Optical fiber is so powerful, there is no doubt that on-line communication through optical fiber cables is our future, and optical fiber will carry most of the traffic. Only fiber optic cable, its long distance, reliability, space saving, anti-interference and relatively low cost can help the public and enterprise operators to control their budget and provide high quality services at a faster rate. FS.COM provides a wide range of fiber optic cables with detailed specifications to facilitate your choice, including simplex/duplex single mode fiber optic cable, as well as OM2/OM3/OM4/OM5 multimode fiber optic cables. Custom service is also available for your specific requirements.

OM4 vs OM3

40G bandwidths are now being widely adopted within LANs and Data Centres. And 100G will soon be required within your local networks. Here comes the question: what type of fibre network you should choose when planning your 40/100 GbE migration. You have to consider your cabling infrastructure and how it will meet your current and future data requirements. The cables of choice for data center connectivity and what is recommended by the TIA are OM3 and OM4 laser-optimized multimode fiber. In this post, a comparison between OM3 and OM4 fibers will be given.

OM3- or OM4-Preferred Fibers in the Data Center

The IEEE 802.3ba 40/100G Ethernet Standard was ratified in June 2010 and specified parallel optics transmission for multimode fiber. OM3 and OM4 are the only multimode fibers included in the standard. OM3 and OM4 laser-optimized 50/125µm multimode fibers are the choice fiber type for connectivity in the data center. The fibers provide a significant value proposition when compared to single-mode fiber, as multimode fiber utilizes low cost 850 nm transceivers for serial and parallel transmission. Below we look at the differences between OM3 and OM4 multi-mode fibers. The picture shows laser-optimized multimode fiber cables.

laser optimised multi-mode fiber cables

Construction of the Fiber Cable

OM3 is fully compatible with OM4. The connectors are the same, the termination of the connectors is the same, the fibre core size 50/125 is the same, and both fibers are laser optimised multi-mode fiber (LOMMF). The difference is just in the construction of the fibre cable. The difference in the construction means that OM4 cable has better attenuation and can operate at higher bandwidth than OM3.

Attenuation: Attenuation is the reduction in power of the light signal as it is transmitted. It is caused by losses in light through the passive components, such as cables, cable splices, and connectors. The difference in OM3 and OM4 performance is in the loss (dB) in the cable. OM4 causes lower losses.

Dispersion: Dispersion is the spreading of the signal in time due to the differing paths the light can take down the fiber. Modal dispersion, which means that the spreading of the signal in time resulting from the different propagation modes in the fiber. OM3 specifies an effective modal bandwidth (EMB) of 2000 MHz/km, and OM4 of 4700 MHz/km, showing that OM4 can operate at higher bandwidth.

Cost Difference

The cost for OM4 is greater due to the manufacture process and economies of scale that the production of OM3 benefits from due to the volumes currently produced. Costs vary depending on the construction type of the cable (loose tube, tight buffered, etc.). OM4 cable is about twice as expensive as OM3 cable. This means that for lots of products such as standard fibre patch panels, MTP cassette modules, fibre patch cords the cost difference is very small (as the volume of cable is small).

What OM4 Gives You That OM3 Doesn’t?

OM4 effectively provides an additional layer of performance that supports these applications at longer distances, as shown in the following picture. OM4 provides an opportunity to future-proof cabling infrastructure, for it can provide a minimum reach of 125m over multimode fiber within the 40 and 100 GbE standards. Additionally, OM4 provides additional reach at extended bandwidth at an overall cost still less than that of an OS2 singlemode system. In other words, OM4 provides a solution that allows more installations to avoid the significantly higher costs of singlemode systems.

transmission distances

Conclusion

It is important to note that OM4 glass is not necessarily designed to be a replacement for OM3. Despite the relatively long-standing availability of OM4, there are no plans to obsolete OM3 fiber optic cabling. Fiberstore offers you a wide range of cable choices for your 40G Ethernet applications, like OM3 and OM4 fiber optic patch cables. And we also offer other 40G components, such as QSFP+ transceiver, copper cable, active optical cable and QSFP+ cable. You can buy from us with confidence.