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What do the fibers OM1, OM2, OM3 and OM4 mean?

When we talk about fiber optic networks, there are many options available to design a network. But the question is, which cable would work best for networking?

SummaryTypes of fiber optic cables are used in telecommunications:A. SEB CABLES. OM CABLESTypes of multimode fiberOM1 fiberOM2 fiberOM3 fiberOM4 fiberOM5 fiberPoints to remember when choosing multimode fiberAdvantages of multimode fiberMulti-user frameworkMulti-protocol supportCost-effectivePackaging

Let's start with the basics to help you understand the critical variations in cable design.

Types of fiber-optic cables are used in telecommunications:

A. Single-mode cable prefixed with "OS".

  1. Multimode cable prefixed with "OM".

A. OS CABLES

OS cables have thinner cores (9 micron core), while OM cables have thicker cores, which can exceed 100 microns.

OS cables are supplied in OS1 and OS2 fiber versions. OS1 is designed for distances less than 2 km, while OS2 is intended for long-range networks up to 200 km.

B. OM CABLES

Multimode fiber is quite cost effective for installations where lengths are a few hundred meters and can be used inside buildings or corporate campuses. By opting for a pre-terminated fiber optic cable , the overall cost can be greatly reduced. In contrast, single-mode fiber is worth longer runs.

Usually, multimode fiber achieves a speed of 10 Gbit/s for a maximum transmission distance of 550 m. Multimode optical fibers have a larger core size, typically a core diameter of 50 µm (OM2-OM5) or 62.5 µm (OM1). More core means that many modes of light are moving through the core simultaneously, which means more data can pass through at any given time. Therefore, the name is "multimode".

Types of multimode fiber

According to ISO 11801, multimode fiber optic cables can be divided into five categories:

  1. OM1 fiber
  2. OM2 fiber
  3. OM3 fiber
  4. OM4 fiber
  5. OM5 fiber (recently released).

But what exactly differentiates them?

These fibers can be differentiated on the basis of core size, data rate, bandwidth, color, distance and optical source.

Starting with the properties of each type of multimode fiber:

OM1 fiber

  • Covered in an orange jacket.
  • Has a core size of 62.5 micrometers.
  • Supports 10 Gigabit Ethernet over lengths up to 33 meters.
  • Often used for 100 megabit Ethernet applications.
  • Uses an LED light source.

OM2 fiber

  • The color of the jacket is orange.
  • Has a core size of 50 micrometers.
  • Supports 10 Gigabit Ethernet over lengths up to 82 meters.
  • Commonly used for 1 Gigabit Ethernet applications.
  • Uses an LED light source.

OM3 fiber

  • The color of the jacket is aqua.
  • Has a core size of 50 micrometers.
  • Works 10 Gigabit Ethernet at lengths up to 300 meters.
  • Can support 40 Gigabit and 100 Gigabit Ethernet up to 100 meters.
  • Commonly used for 10 Gigabit Ethernet applications.
  • Optimized for laser tape equipment.

OM4 fiber

  • In the color of the Aqua jacket.
  • Has a core size of 50 micrometers but an improved version of OM3.
  • Holds 10 Gigabit Ethernet at lengths up to 550 meters and supports 40/100 Gigabit
  • Ethernet over lengths up to 150 meters using an MPO connector.
  • Specially developed for VSCEL laser transmission.

OM5 fiber

  • It was released in 2014 and is also known as Wideband Multimode Fiber (WB MMF).
  • The color of the jacket is lime green.
  • Have similar characteristics to OM4 (same EMB limitations and 10/40/100 Gb Ethernet distance).
  • It is specifically designed to support a minimum of four WDM channels at the lowest speed of 28 Gbps per channel across the 850-953 micron window.
MMF cable type Jacket color Optical source Diameter Bandwidth OM1OrangeLED62.5/125µm200MHz*kmOM2OrangeLED50/125µm500MHz*kmOM3AquaVSCEL50/125µm2000MHz*kmOM4AquaVSCEL50/125µm4700MHz*kmOM5Lime GreenVSCEL50/125µm28000MHz*km

Points to remember when choosing multimode fiber

  • Due to the difference in core size of OM1 (62.5 micrometers), it is not directly compatible with other types of multimode, be it OM2, OM3, OM4, OM5, and none cannot accept the same connectors.
  • Please match core size for mechanical connectors to ensure signal continuity through the connector.
  • The outer sheath of OM1 and OM2 is orange in color. It is always advisable to check the legend printed on the cable if the correct connector is being used.
  • Previously, OM1 and OM2 were designed with LED emitters, but later, due to modulation limitations of LEDs and the need for increased speed, Laser Optimized Multimode Fibers (LOMMF) OM3 OM4 and OM5 have been introduced.

Please note:

  • For short runs, OM1 fibers are economical.
  • The transmission makes a major difference. Although OM1 and OM2 are inexpensive and reach maximum speeds of around 1 Gbps, both use LED transmitters and LEDs are bandwidth limiting.
  • As OM3 and OM4 both use Laser Optimized Multimode Transmission (LOMMF), it is expensive to use but allows for higher bandwidths and can speed up to 10 Gbps and 40 Gbps, respectively.

Advantages of multimode fiber

Multi-user-framework

Multimode fiber carries multiple signals at the same time on the same line without any interference or impairment.

Multiple-protocol support

Multimode fiber can be used for high-value applications as it can support various data transfer protocols such as Ethernet, Infiniband, and Internet protocols.

Profitable

Multimode fiber can work with optical components such as fiber connectors and fiber adapters and is easy and economical to install, operate and maintain.

Pack

Hopefully the above details on multimode fiber would be helpful. Falcon Technologies Inc . has a wide variety of fiber optic cables. Depending on the application, transmission distance and budget, you can choose which fiber cable is suitable for your project? If in doubt, contact our fiber cable experts to help you choose the right fiber cable.