Multi mode  vs Single mode  SFP：What's the difference?

Some customers want to know about the difference between multimode and single mode SFP , so we summarize some information about multimode and single-mode.The following is some concepts and the differences between multimode and single-mode SFP.

According to the wavelength,there are 850nm / 1310nm / 1550nm / 1490nm / 1530nm / 1610nm.850nm wavelength is fit for multimode SFP, transmission distance is below 2KM; 1310/1550nm wavelength is fit for single-mode SFP, transmission distance is over 2KM. Generally, the price of these three wavelengths is lower than the other three.
The raw modules are easily confused if there is no identity, the manufacturers will be distinguished in the color of the ring generally. For example: The black ring is multimode and the wavelength is 850nm; The blue, yellow and purple ring is single-mode, the wavelengths are 1310nm, 1550nm, 1490nm.

The distinguishing factor between Multimode SFP and Singlemode SFP lies in the type of fiber they are designed to work with, the distances they can cover, and the cost associated with each one. Here's an in-depth look at each one.

Multimode SFP:

Multimode SFPs are primarily designed for large-bandwidth application within a relatively short range, generally up to 2 kilometers. They are used in conjunction with multimode fiber, which has a larger core diameter than single mode fiber. The larger core allows multiple paths for light rays or modes (hence "multi" mode) to propagate within the fiber. 

Multimode SFPs operate at 850nm wavelength and are often utilized for their lower cost both for modules and connectors, as well as the fiber itself. The large core size allows for cheaper and less sophisticated equipment to inject light into the cable. Thus, they are typically used for short range, high-speed connections, such as within a data center or campus network.
 

Singlemode SFP:

Singlemode SFPs work with singlemode fiber, which has a smaller core diameter that only allows one path or mode of light (hence "single" mode) to propagate. This smaller diameter eliminates multi-path distortion that can result in signal loss, hence capable of achieving higher transmission speed and greater distance. Singlemode SFPs operate at 1310nm or 1550nm wavelength and can transmit data over a distance up to 120 kilometers.

Due to the fact that light in a singlemode fiber always takes the straight path to reach the other end, there is no signal distortion or loss, offering a higher bandwidth than multimode fibers. However, the tighter tolerances required by singlemode fibers make the connectors and equipment more expensive compared to a multimode setup.

 

What is multi mode SFP?

Multimode SFP, or Small Form-factor Pluggable, is a type of optical transceiver module designed to work with multimode fiber optic cables. 

Multimode fiber optic cables have a larger core diameter than singlemode fibers and are designed to carry multiple beams or modes of light simultaneously. This is where the term "multimode" derives from. Because of these multiple paths, multimode fibers are generally used for shorter distances as the multiple pathways can cause signal dispersion which affects the quality of the data transmission over longer stretches.

Multimode SFPs typically operate at a wavelength of 850nm, connecting over short distances of up to 2 kilometers (approximately 1.2 miles). These transceivers are typically used within buildings or on single campuses for Local Area Networks (LANs), and computer and storage networks where cost is a more significant factor than distance. 

Multimode SFPs are typically less expensive than singlemode SFPs, both in terms of the transceiver itself and the associated connectivity components, making them a cost-effective solution for high-speed, short-distance data transmissions. They are widely used in applications such as Ethernet, Fast Ethernet, Gigabit Ethernet, and other datacom and telecom optical links.

Multi-mode fiber uses a much bigger core and usually uses a longer wavelength of light. Because of this, the optics used in Multi-mode have a higher capability to gather light from the laser. In practical terms, this means the optics are cheaper. The common Multi-mode SFPs work in 850nm wavelength and is only used for short distance transmission reaching 100m and 500m. Though it’s not able to transport for long distance, it can transport many kinds of optical signals.
 

MULTI-MODE SFP COLOR CODING

As with Singlemode SFPs, Multi-Mode SFPs are identified by the color of the Bale Clasp:

• Black color coded bale clasp designates a Multi-mode SFP

• The color of the compatible fiber optic patch cord or pigtail is orange
  
   

What is single mode sfp?

Single Mode SFP, or Small Form-factor Pluggable, is an optical transceiver module designed to work with single-mode fiber optic cables. 

Single-mode fiber optic cables have a smaller core diameter than multimode fibers and are designed to carry only a single beam or mode of light, hence “single mode”. This design, which restricts light propagation to a single straight ray, helps the signal travel directly down the fiber without bouncing off the walls and causing signal loss.

Single Mode SFPs typically operate at wavelengths of 1310nm or 1550nm. They are capable of transmitting data over larger distances, often up to dozens or even a hundred kilometers, making them an ideal choice for long-distance communication. 

Due to the high precision of the lasers used and the complexity of the single-mode fibers, Single Mode SFPs and associated components are often more expensive than their multimode counterparts. Despite the cost, they are essential for applications that require high-speed, long-haul data transmission such as broadband networks, metropolitan area networks, and subsea communications.

SFPs are identified by the color of the Bale Clasp. Though there is still a lack of total conformity; generally speaking, Singlemode SFPs use this color coding:

• Gray color coded bale clasp designates the 1470 nm SFP

• Violet color coded bale clasp designates the 1490 nm SFP

• Blue color coded bale clasp designates the 1510 nm SFP

• Green color coded bale clasp designates the 1530 nm SFP

• Yellow color coded bale clasp designates the 1550 nm SFP

• Orange color coded bale clasp designates the 1570 nm SFP

• Red color coded bale clasp designates the 1590 nm laser SFP

• Brown color coded bale clasp designates the 1610 nm SFP

• The color of the compatible fiber optic patch cord or pigtail is yellow

Comparison:

In essence, the choice between multimode SFP and singlemode SFP depends largely on the specific network demands. If short distances are involved, multimode SFPs can provide a cost-effective solution for swift, large-bandwidth data transmission. In contrast, for longer distances and high-speed requirements, singlemode SFPs are undoubtedly more suitable despite the higher costs involved.

One should keep in mind that while these two types of SFPs are not interoperable due to their differing operational principles, they remain vital parts of modern optical networks catering to the varying needs of different network scales and applications.

 

How to buy And Use Single Mode SFP & Multimode SFP?

When we buying single mode SFP or multimode SFP in the market, we must confirm the transmission distance and wavelength we need. This will help us to choose the right SFP types more efficiently. The cost for transceiver modules is also a significant factor considered by many users. Well, the compatible SFP moduleshould be recommended as a simple and convenient choice. Because it not only sacrifices no quality or reliability but also has a low cost. Hope these tips could help you make an informed decision.

Tips on using Single Mode SFP & Multimode SFP

Single mode SFP and multimode SFP modules are both used in the switch slot and support communication over either fiber optic or copper networking cable. When you use single mode SFP or multimode SFP, you’d better keep these tips in mind:

• Make sure that SFPs in both ends of the fiber patch cord are of the same wavelength and consistent in color coding.

• To ensure the data accuracy, short-wave SFP modules are generally utilized with multimode fibers (ie. orange fiber patch cord), while long-wave SFP modules with single mode fiber (ie. yellow fiber patch cord).

• Protect the optical port by dust plug when not using the SFP.
  
   

Single Mode SFP vs Multimode SFP：Which One to Choose?

After the comparison of single mode SFP vs multimode SFP, we can see that single mode SFP is suitable for long-reach data transmission applications while multimode SFP is generally utilized for short transmission distance. Which to choose depends on the actual needs. FS supplies various kinds of optic transceivers available in both single-mode and multimode. If you have any needs, welcome to visit FS.COM.

 

How to buy And Use Single Mode SFP & Multimode SFP?

When we buy single mode SFP or multimode SFP in the market, we must confirm the transmission distance and wavelength we need. This will help us to choose the right SFP types more efficiently. The cost for transceiver modules is also a significant factor considered by many users. Well, the compatible SFP module should be recommended as a simple and convenient choice. Because it not only sacrifices no quality or reliability but also has a low cost. Hope these tips could help you make an informed decision.