Multimode optical fiber OM1 OM2 OM3 OM4 OM5 parameter comparison

Optical fibers are generally divided into single mode fibers and multi-mode fibers. This time we will mainly start with multimode fibers. When multimode fiber transmits signals, it allows a variety of different transmission modes. Due to the influence of modal dispersion caused by multimode transmission, the transmission distance is limited. Let’s start directly by introducing the OM series of multimode fibers.

Multimode Fiber Standards

There are many standards for multimode fiber, specifically the multimode fiber standard defined by the TIA organization and later adopted by the ISO/IEC organization.

“OM”is optical mode, is the standard for multi-mode fiber to express fiber grade. The bandwidth and maximum distance of different levels of transmission are different.

If you want to know the specific parameters of these 5 specifications as quickly as possible, just click to enlarge the table below.

OM1 OM2 OM3 OM4 quick comparison

Let’s start with the comparison of OM1/2/3/4.

OM5 is a new type of broadband optical fiber, single-mode optical fiber/multi-mode optical fiber/step optical fiber/gradient optical fiber. We will analyze it separately.

Comparison of technical parameters

【OM1】

Refers to 50um or 62.5um core diameter multimode fiber with 850/1300nm full injection bandwidth above 200/500MHz.km.

【OM2】

Refers to 50um or 62.5um core diameter multimode fiber with 850/1300nm full injection bandwidth above 500/500MHz.km.

【OM3】

It is an 850nm laser optimized 50um core diameter multi-mode optical fiber. In a 10Gb/s Ethernet using 850nm VCSEL, the optical fiber transmission distance can reach 300m.

【OM4】

It is an upgraded version of OM3 multi-mode optical fiber, and the optical fiber transmission distance can reach 550m.

Comparison of internal structure of optical fiber

【OM1 and OM2】

Both OM1 and OM2 use LED (Light Emitting Diode) as the basic light source in terms of standard and design.

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【OM3 and OM4】

OM3 and OM4 are optimized on the basis of OM2, making them suitable for transmission where the light source is LD (Laser Diode). Compared with OM1 and OM2, OM3 has higher transmission rate and bandwidth, so it is called optimized multimode fiber or 10G multimode fiber.

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Comparison of fiber optic functions and features

【OM1】

The core diameter and numerical aperture are large, and it has strong light-gathering ability and anti-bending properties.

【OM2】

The core diameter and numerical aperture are relatively small, which effectively reduces the modal dispersion of multi-mode optical fiber, significantly increases the bandwidth, and reduces the production cost by 1/3.

【OM3】

The use of flame-retardant outer skin can prevent the spread of flames, prevent the emission of smoke, acidic gases and poisonous gases, and meet the needs of 10 Gb/s transmission rate.

【OM4】

Developed for VSCEL laser transmission, the effective bandwidth is more than double that of OM3.

Comparison of fiber optic application scenarios

OM1 OM2 Application Environment-Inside Buildings

【OM1 and OM2】

OM1 and OM2 have been widely deployed in in-building applications for many years, supporting Ethernet transmission up to 1Gb.

OM3 OM4 application environment-data center

【OM3 and OM4】

OM3 and OM4 optical cables are commonly used in data center cabling environments and support the transmission of 10G or even 40/100G high-speed Ethernet networks.

OM5

After talking about the comparison between them, let’s go into a separate session and introduce OM5.

OM5 fiber, known as broadband multimode fiber patch cord, is a laser-optimized multimode fiber with bandwidth characteristics specifically specified for wavelength division multiplexing.

This new fiber classification method is designed to provide support for a variety of “short” wavelengths between 850nm and 950nm, which when aggregated are suitable for high-bandwidth applications. The design of OM3 and OM4 is mainly to support a single wavelength of 850nm.

Less fiber support, higher bandwidth applications

The working wavelength of OM5 fiber jumper is 850/1300nm and can support at least 4 wavelengths. The usual operating wavelengths of OM3 and OM4 are 850nm and 1300nm. In other words, traditional OM1, OM2, OM3, and OM4 multimode optical fibers have only one channel, while OM5 has four channels, increasing the transmission capacity by four times.

Combining shortwave wavelength division multiplexing (SWDM) and parallel transmission technology, OM5 only requires 8-core wideband multimode fiber (WBMMF) to support 200/400G Ethernet applications, greatly reducing the number of fiber cores and reducing network wiring costs to a great extent.

Longer transmission distance

OM4:100M, OM5:150m, when using 100G-SWDM4 transceiver

The transmission distance of OM5 optical fiber is longer than that of OM3 and OM4. OM4 fiber is designed to support lengths of at least 100 meters with 100G-SWDM4 transceivers. But OM5 fiber can support lengths up to 150 meters with the same transceiver.

Lower fiber loss

The attenuation of OM5 broadband multimode optical cable has been reduced from 3.5 dB/km of previous OM3 and OM4 optical cables to 3.0 dB/km, and the bandwidth requirement at the 953nm wavelength has also been increased.

Fully compatible with OM3 and OM4

OM5 has the same fiber size as OM3 and OM4, which means it is fully compatible with OM3 and OM4, and no changes are required to apply OM5 to existing cabling.

OM5 fiber is more scalable and flexible and can support higher-speed network transmission with fewer multi-mode fiber cores, while the cost and power consumption are much lower than single-mode fiber.