Multimode fiber is a popular choice for local area network enterprise and data center applications that require distances to reach 10gbit /s speeds. There are several multimode fibers available for high-speed network installations, each with different coverage and data rate capabilities. With so many options, it is difficult to select the most appropriate multimodefiber. OM1 vs OM2 vs OM3 vs OM4 vs OM5, how to choose? Today, we're going to talk about that.
What is multimode fiber?
Multimode fiber (MMF) is a type of optical fiber that is primarily used for short-range communications, such as within buildings or campuses. Multimode fiber optic cables have large cores, typically 50 or 62.5 micrometers, and can propagate multiple optical modes. Because of this, more data can pass through the multimode fiber core at a given time. The
MMF cable has a maximum transmission distance of about 550 m at 10Git/s and can also transmit longer distances at a lower data rate, for example about 2 km at 100Mb/s.
How many kinds of multimode fibers are there?
According to the ISO 11801 standard, multimode fiber optic cables can be divided into OM1 fiber, OM2 fiber, OM3 fiber, OM4 fiber and the newly released OM5 fiber. Next, we compare these fibers in detail in terms of core size, bandwidth, data rate, distance, color, and light source.
OM1 optical fiber
The OM1 fiber usually comes with an orange sheath and has a core size of 62.5µm. It can support 10 Gb Ethernet up to 33 meters long. It is most commonly used in 100 Megabit Ethernet applications. This type usually uses LED light sources.
OM2 optical fiber
Similarly, the OM2 fiber also comes with an orange sheath and uses an LED light source, but with a smaller core size of 50µm. It supports 10 Gb Ethernet up to 82 meters, but is more commonly used for 1Gb Ethernet applications.
OM3 optical fiber
OM3 fiber with light green sheath. Like OM2, the core size is 50 µm, but the cable is optimized for laser-based devices. OM3 supports 10 Gb Ethernet up to 300 meters in length. In addition, OM3 is able to support 40G and 100G Ethernet up to 100 meters away, but 10G Ethernet is most commonly used.
OM4 optical fiber
The OM4 fiber is fully backward compatible with the OM3 fiber and shares the same unique aqua sheath. The OM4 was developed specifically for VSCEL laser transmission and has a 10Gig/s link distance of up to 550m compared to the 300 m of OM3. It is capable of running 40/100GB at distances up to 150 m using MPO connectors.
OM5 optical fiber
OM5 fiber, also known as WBMMF (Wideband Multimode Fiber), is the latest multimode fiber and is backward compatible with OM4. Its core size is the same as OM2, OM3, and OM4. The color of the OM5 fiber sheath was chosen as lime green. It is designed and specificated to support at least four WDM channels through an 850-953 nm window, each with a minimum speed of 28Gbps.
What is the difference between OM1, OM2, OM3, OM4, and OM5?
The main difference between multimode fibers is the physical difference. Therefore, physical differences lead to different transmission data rates and distances.
Physical differences
The physical differences are mainly in diameter, sheath color, light source, and bandwidth, as described in the following table.
TAPE | COLOR | |||
OM1 | 62.5/125µm | Orange | LED | 200MHz*km |
OM2 | 50/125µm | Orange | LED | 500MHz*km |
OM3 | 50/125µm | Aqua | VSCEL | 2000MHz*km |
OM4 | 50/125µm | Aqua | VSCEL | 4700MHz*km |
OM5 | 50/125µm | Lime Green | VSCEL | 28000MHz*km |
Actual difference
Multimode fibers are capable of transmitting different distance ranges at different data rates. The most suitable one can be selected according to the actual application. The maximum multimode fiber distance comparison for different data rates is specified below.
TYPE | 1GbE | 10GbE | 40GbE | 100GbE | |
OM1 | 2000m | 275m | 33m | / | / |
OM2 | 2000m | 550m | 82m | / | / |
OM3 | 2000m | / | 300m | 100m | 70m |
OM4 | 2000m | / | 550m | 150m | 150m |
OM5 | / | / | 550m | 150m | 150m |
What is the difference between single-mode and multimode fiber?
Technical differences
Core Diameter - Single-mode fibers have a small diameter core (8.3 to 10 microns) that allows only one mode of light to propagate. Multimode fiber optic cables have large diameter cores (50 to 100 micmeters) that allow multiple modes of light propagation.
Light source -Multimode devices typically use leds or lasers as light sources. Single-mode devices, on the other hand, use lasers or laser diodes to generate light that is injected into the cable.
Actual difference
Distance -Light travels longer in a single-mode cable than in a multimode cable. Therefore, multimode fiber is suitable for short-range applications, allowing transmission distances up to about 550 meters at 10Git/s. When the distance exceeds 550 m, the single-mode fiber is preferred.
Price -the cost of multimode fiber is usually lower than that of single-mode fiber.
Bandwidth - The bandwidth of single mode is higher than that of multiple mode up to 100,000 GHz.
Multimode fiber connector type
The types of multimode fiber connectors in circulation on the market are ST, SC, FC, LC, MU, E2000, MTRJ, SMA, DIN and MTP&MPO, etc. The most commonly used types of fiber connectors are ST, SC, FC and LC. Each has its own strengths, weaknesses, and capabilities. So what are the differences, and what do they mean for implementation? This table of common multimode fiber connectors Outlines the advantages and disadvantages.
TYPE | SIZE | (dB) |
SC | φ2.5mm ceramic | 0.25-0.5 |
LC | φ1.25mm ceramic | 0.25-0.5 |
FC | φ2.5mm ceramic | 0.25-0.5 |
ST | φ2.5mm ceramic | 0.25-0.5 |
What are the advantages of multimode fiber?
While single-mode fiber jumpers offer advantages in terms of bandwidth and longer distances, multimode fiber can easily support most of the distances required by enterprise and data center networks at a much lower cost than single-mode fiber. In addition, multimode fiber optic cable has many significant advantages.
A Multiuser Framework for lossless Interference
Multimode fiber has the characteristic of carrying multiple signals simultaneously in the same line. Most importantly, there is little loss of total power in the signal. Therefore, the network user can send more than one packet in the cable at the same time, and all the information will be delivered to the destination without interference and remain unchanged.
Support multiple protocols
Multimode fiber can support a variety of data transfer protocols, including Ethernet, Infiniband, and Internet Protocol. Therefore, cables can be used as the backbone for a range of high-value applications.
High cost performance
With larger cores and good alignment tolerances, multimode fibers and components are cheaper and easier to use with other optical components such as fiber connectors and fiber adapters, and multimode jumpers are less expensive to operate, install, and maintain than single-mode fiber cables.
Conclusion
Multimode fibers are commonly used for backbone applications in buildings due to their high capacity and reliability. Overall, multimode fiber optic cables remain the most cost-effective option for enterprise and data center applications within 500-600 meters. However, this does not mean that we can replace single-mode fiber with multi-mode fiber cable, as for the choice of single-mode fiber jumper or multi-mode jumper, it depends on the specific needs of the application, such as the transmission distance to cover, the overall budget and so on.
