Understanding Various Types of Fiber Optic Cabling: Multimode vs. Singlemode

Multimode vs. Singlemode: The Basics

At the heart of the distinction between multimode and singlemode fibers lies the size of their optical cores. Multimode fibers have a larger core typically ranging from 50 to 62.5 micrometers, while singlemode fibers boast a significantly smaller core, around 9 micrometers in diameter.

Here are some useful facts to consider:

• OM1 (62.5 µm) fiber has reached its performance limit
• In lab testing, 50 µm fiber offers as much as ten times the bandwidth of 62.5 µm fiber
• OM3 and OM4 fibers will support upcoming 40 and 100 Gb/s speeds. Only OM3 and OM4 Multimode fibers are included in the IEEE 802.3ba standard for next-generation 40 and 100 Gb/s Ethernet. OM1 and OM2 fibers are not supported media types for these applications.
• Mixing fiber types is strongly not recommended.
  Please read the above article for more information on this.

This core size differential leads to fundamental differences in their transmission properties.

In this video we discuss the different types of fiber optic cable and their connection to speed and distance.

Types of classifications for multimode core sizes

The Multimode core sizes come in different classifications: OM1, OM2, OM3, OM4, and OM5 while singlemode only has one.

Multimode fiber solutions, featuring larger cores for transmitting multiple modes, can handle more data than single-mode options.

However, they operate at slower speeds and carry a higher risk of attenuation, making them suitable for short-range networks. These cables come with either step or graded index cladding, each affecting mode refraction differently.

OM1

OM1 or 62.5/125 Fiber is the largest fiber core, therefore the light has more time to bounce around or reflect, and it takes longer for it to reach the end point.

OM1 Fiber supports 1 Gigabit Ethernet to 275 meters and can support 10 Gigabit Ethernet up to 33 meters.

OM1 fiber is not the best choice for a 10 Gig network as it has the lowest data carrying capacity and shortest distance limitations.

OM2

OM2 Fiber is in the 50/125 classification but is more in line with OM1 fiber in terms of speed and distance.

OM2 fiber can support 1 Gigabit ethernet up to 550 meters but can only support 10 Gigabit Ethernet up to 82 meters.

With the advance of OM3 fiber, OM2 has become essentially phased out in the industry.

OM3

OM3 is usually just referred to as 10 Gig since it's generally the best choice for 10 Gigabyte networks. Multimode fiber was designed specifically for that purpose.

OM3 fiber can support 1 Gigabit ethernet up to 550 meters and can support 10 Gigabit Ethernet up to 300 meters. In addition, it can also support 40 Gig up to 100 meters, and 100 Gig up to 70 meters.

OM4

OM4 fiber is backwards compatible with OM3 fiber and was developed for VCSEL laser transmission.

OM4 fiber can support 10 Gigabit ethernet up to 550 meters and it can also support 40 and 100 Gig up to 150 meters.

OM5

OM5 fiber also known as SWDM or Shortwave Wavelength-division multiplexing fiber is downwards compatible with OM4 fiber and has the ability to use four wavelengths across the 850 to 950 nm range.

But for comparative purposes as a single signal, OM5 fiber can support 10 Gigabit ethernet up to 550 meters and it can also support 40 and 100 Gig up to 150 meters.

Singlemode

Singlemode fiber has the smallest fiber core, and therefore there is less room for the light to reflect and has less attenuation.

Single-mode cables, with their thin glass fiber cores transmitting single rays of light, are optimal for long-distance connections due to their resistance to attenuation. However, their intricate production processes make them pricier than their multimode counterparts.

Singlemode fiber can transmit light at much longer distances, but OM3/OM4/ and OM5 multimode fiber supports a higher data rates.

Singlemode fiber can support 1 Gigabit ethernet up to 5 kilometers and it can also support 10 Gigabit ethernet up to 10 kilometers.

How far can multimode and singlemode fiber travel?

One of the first considerations when choosing between multimode and singlemode fibers is the maximum distance they can transmit data.

Multimode fibers are well-suited for shorter distances, typically ranging from a few hundred meters up to a few kilometers. Beyond these distances, multimode fibers may experience signal loss and dispersion, making them unsuitable for long-haul applications.

Multimode fibers are commonly used for lower-speed applications, such as local area networks (LANs) and short-distance connections within buildings. They are cost-effective and provide sufficient bandwidth for these purposes.

On the other hand, singlemode fibers excel in long-distance transmission. They can carry signals for tens of kilometers, reaching distances that are simply unattainable for multimode fibers.

Singlemode fibers have minimal signal loss and dispersion due to their smaller core size, making them the preferred choice for intercontinental and high-capacity data transmissions.

In contrast, singlemode fibers are the go-to choice for high-speed, long-distance transmissions, including metropolitan area networks (MANs) and wide area networks (WANs). They offer low signal attenuation and dispersion, making them ideal for high-capacity data transfers.

Limitations of various fiber core types

As you can see from the chart below, different Fiber core types have vastly different limitations for speed and maximum distance.

The 62.5/125 µm (AKA: OM1) has been the most popular multimode fiber choice throughout the 80's, 90's and into the early 2000's and was the most common multimode fiber used and yet it has the lowest data carrying capacity and shortest distance limitations as compared with other Multimode fiber types. It is generally accepted that 62.5/125 Multimode will soon be obsolete for the purpose of new installations.

NOTE: If you currently have 62.5/125 µm fiber installed in your office, building or campus you need to continue to use 62.5/125 µm fiber patch cables to connect to it. Attempting to mate two different fiber core sizes can lead to high loss and is therefore strongly not recommended.

The 50/125 µm core size comes in three different classifications (OM2, OM3 and OM4). Please note that OM3 is usually just referred to as 10GIG since it is generally the best choice for 10 Gigabit Ethernet over Multimode fiber and was designed specifically for that purpose (unless you need the extra distance provided by OM4).

How to Select the Correct Fiber Optics Cable

Fiber optic cables find use in both indoor and outdoor settings, each demanding specific installations.

Outside-plant networks typically utilize buried single-mode solutions, while underwater implementations, like transatlantic submarine cables, are commonplace.

On-premises installations, dealing with existing structures and building codes, often employ multimode fiber for local area networks (LANs). Centralized fiber cabling is gaining popularity for its simplicity, not requiring grounding, power, or temperature control. Installers typically specialize in either outside-plant or on-premises applications due to the differing work requirements.

Choosing the right fiber optic cable involves considering various factors, including the distance of the transmission, data speed requirements, and budget constraints. Here are some key considerations:

Distance

For short-distance connections within a building or data center, multimode fiber is suitable. For longer distances or intercontinental connections, singlemode fiber is the preferred choice.

Data Speed

If your network demands high data speeds, singlemode fiber is the better option. However, for lower-speed applications, multimode fiber can be cost-effective.

Budget

Multimode fiber tends to be more budget-friendly, making it a practical choice for shorter distances and when cost constraints are a concern.

In recent years, the cost of singlemode fiber and related components has decreased significantly. This development has led to increased versatility in fiber optic network design.

It is now possible to use singlemode fiber in short lengths for specific applications where it was previously considered too expensive.

Additionally, multimode fibers continue to excel in short-distance scenarios, providing ample bandwidth for high-speed data transfers within confined spaces. As a result, they remain a valuable choice for many modern applications.

Future-Proofing

Consider future expansion plans and the potential need for higher data speeds. Choosing singlemode fiber may be a wise investment if future scalability is a priority.

Compatibility

Ensure that the chosen fiber type aligns with the optical transceiver modules and equipment used in your network.

Example Scenarios for choosing one over the other

Data Centers

Consider a data center requiring a reliable, high-speed connection between two locations within the same building. In this case, multimode fiber would be the ideal choice due to its compatibility with short to medium-range transmissions.

Suppose a large corporation is expanding its data center infrastructure, requiring both short-distance connections within the data center (multimode) and long-distance connections to remote offices (singlemode).

In this scenario, a carefully planned network design would involve using appropriate mode conditioning patch cables and ensuring that power levels match the specific fiber type and module.

Telecommunications

Imagine a telecommunications company aiming to upgrade its long-distance communication infrastructure. In this case, singlemode optical transceiver modules are indispensable, as they can harness the capabilities of singlemode fibers to transmit data across vast distances with minimal signal loss.

University Campus

Picture a university campus with multiple buildings requiring internet connectivity.

Multimode fibers may be sufficient for connecting different departments within a building, while singlemode fibers would be essential for linking buildings scattered across the campus, ensuring high-speed and reliable data transmission.

Small start ups

A small startup company is setting up its office network. While they initially only require a basic LAN setup, they anticipate rapid growth and future expansion. In this case, it would be wise to install singlemode fiber from the outset to accommodate future high-speed data requirements.

Conclusion

In the world of fiber optic cabling, the choice between multimode and singlemode fibers is a critical decision that can significantly impact the performance and cost-effectiveness of your network.

Understanding the differences between these fiber types and their applications is essential for making.

FAQ

What is the difference between singlemode and multimode optical transceiver modules?

Optical transceiver modules play a pivotal role in fiber optic networks, acting as the interface between the fiber cable and networking equipment. These modules come in both singlemode and multimode variants, designed to match the specific fiber type being used. The primary difference between the two lies in the light source they employ.

Multimode optical transceiver modules utilize light-emitting diodes (LEDs) as their light source, which produce a broader spectrum of light. This allows them to work with the larger core of multimode fibers effectively. Singlemode optical transceiver modules, on the other hand, use laser diodes, emitting a narrower, more focused beam of light suitable for the smaller core of singlemode fibers.

Can singlemode/multimode fiber be mixed with singlemode/multimode optical modules?

Mixing fiber types and optical modules may be necessary in certain network configurations.

Here at LANshack, we never recommend mixing fiber types as there would be too much attenuation (data loss) in the connection.

That being said, it is possible to mix singlemode and multimode fibers. You must ensure that the optical power levels are compatible as mismatched power levels can lead to signal loss and poor network performance.

Select the Right Fiber Provider

The market is saturated with fiber optic cable providers, varying in product quality and support. With the recent surge in demand, many networking resource providers have entered the fiber market. To ensure a successful fiber adoption, businesses should thoroughly vet potential partners, seeking those offering proven solutions, prompt technical support, and fast shipping.

By adhering to these best practices, organizations can implement efficient and productive fiber-based networks without exceeding budget constraints.

Is your organization ready for fiber optic technology? Consider partnering with LAN Shack, specializing in pre-terminated fiber optic assemblies supporting businesses across industries for over 20 years. Contact us today to discover how we can help keep your enterprise connected.