Difference Between Single Mode and Multimode Fiber (With Table)

Fiber optics, also known as optical fiber, is an innovation that sends data as light pulses across a glass or plastic fiber. The number of glass fibers in a fiber optic cable can tend to fluctuate from hundreds to thousands. Single-mode fiber and multimode fiber are just two types of optical fiber.

Single-mode Fiber vs Multimode Fiber

The difference between single-mode and the multimode optical fiber is that light rays perpetuate only through a straight route in single-mode optical fiber. On the other hand, numerous rays of light distribute through the waveguide at the very same time in multimode optical fiber. Along with this, several other factors are differentiating between the two.

Single-mode fiber is a type of optical fiber that is used for transmitting over large distances. It is basically a single mode fiber which is used to transmit a single ray of light or a single mode. It has only one transmission mode. It is sometimes called as mono-mode optical fiber.

Multimode fiber is yet another type of optical fiber that is used for transmitting numerous rays of light or modes. These rays can be transmitted at different angles and at much shorter distances. It is composed of glass fibers. Multimode fiber is also more commonly known as multimode optical fiber.

Comparison Table Between Single Mode and Multimode Fiber


Parameters of Comparison
Single Mode FiberMultimode Fiber
DiameterThe central diameter of a single mode fiber is approximately about 8-10 micrometers in length.The central diameter of a multimode fiber is approximately about 50-62.5 micrometers in length.
Optical SourceThe optical source of a single mode fiber is a laser because it requires a source of light with a thin spectral size.The optical source of a multimode fiber is a LED because it requires a huge, central diameter which eliminates the need for a focused beam.
AttenuationBecause a single mode fiber transmits a single ray of light, the result is in less attenuation.Because a multimode fiber transmits numerous rays of light, the result is in more attenuation.
CostSingle mode optical fibers are less expensive, but the instruments needed with it make it a bit costly sometimes.Multimode optical fibers are much more expensive, but the instruments needed with it do not add more cost as in other optical fibers.
BandwidthSingle-mode fiber has a greater bandwidth of about 400 MHz/km.Multimode fiber has a much lesser brandwidth of about 50-60 MHz/km.

What Is Single Mode Fiber?

A single-mode optical fiber is a kind of optical fiber that enables only one ray of light to propagate along with it. The diameter of the centre to the enclosure is 9 to 125 micrometers in this case. It is also referred to as mono-mode optical fiber or uni-mode optical fiber. All of the benefits connected with single-mode optical fiber make it appropriate for usages with arising optical innovations.

Because the diameter of the centre is so tiny, only a single light beam passes via the same.  A single optical fiber is recognized to have three basic components: the core, the cladding, and the coating or the buffer.

The centre, or vital part, is made up of only one fiber strand. The beam radiated by the origin passes via this segment. The minuscule diameter of the centre necessitates the utilisation of a sharply focused beam of light as its origin. As a result, it employs a LASER as its optical point of origin.

Single-mode optical fiber has low waveform deformation because it transmits only a solitary light ray. As a result, modal distribution is not observed, allowing for long-distance frequency transfer with noticeably increased flow pace. As a consequence, the bandwidth is increased, which is an additional benefit of single-mode optical fiber.

What Is Multimode Fiber?

Multimode optical fiber is also another form of digital fiber. Numerous rays of light perpetuate through a multimode optical fibre at the same moment, but each tends to reflect at a distinct slant than the others during transfer.

In the scenario of multimode optical fiber, the centre to cladding diameter ranges from 50-62.5 to 125 micrometres. Due to their reliability and performance, multimode fibers are often the first preference whenever a link within a building is considered necessary. The costs might be a bit expensive, but in the end, it is worth it for the users.

In this scenario, the diameter of the centre point is enormous, enabling innumerable light waves to cross through it and thereby utilising LED as its optical source. There are too much possibilities for modes to communicate with one another since many modes intensify through the centre point. As a consequence, intermodal transmission can occur in multimode fibres.

Because long-distance transfer increases the possibility of scattering within the fibre, these are most often used in applications requiring small distances. Although multimode fiber is a costly optical fiber, the transfer hardware affiliated with it is less pricey, thus making it a suitable choice for most users.

Main Differences Between Single Mode and Multimode Fiber

  1. The central diameter of a single-mode optical fiber is around 8 to 10 micrometres, but the central diameter of a multimode optical fiber is approximately 50 to 62.5 micrometres.
  2. Because single-mode optical fibers have tiny diameters, they are more difficult to handle and couple than multimode optical fibers.
  3. In single-mode optical fiber, the transmission of a single light beam results in reduced attenuation. However, attenuation in multimode optical fiber is greater due to many bounces of light rays.
  4. Single-mode optical fibers are less costly than multimode optical fibers; yet, the equipment connected with single-mode optical fibers are more pricey than multimode optical fibers.
  5. Because single-mode optical fibre has lower losses than multimode optical fibre, it can transport a specific signal across a greater range. When opposed to multimode fibre, the transfer range of single-mode fibre is roughly 50 times larger.

Conclusion

Single mode and multimode fibers each have their unique distinct properties. As a result, their application is determined by the system’s requirements. It is worth noting that the transfer wavelength of single-mode fiber ranges from 1260 to 1640 nm and that of multimode fibre ranges from 850 to 1300 nm.

Single mode fiber has a narrower center than multimode fiber and is best suited for long-distance deployments. In general, single mode systems are more costly. Multimode fibre has a bigger core and is suited for shorter fibre lines of less than 400 metres (1300 feet). 

The distance and bandwidth capacities of multimode fibre are affected by its grade. In general, multimode systems are less costly. Single mode is only compatible with single mode, while multimode is only compatible with multimode. This is applicable for cable, connections, and electrical components.

References

  1. https://www.osapublishing.org/abstract.cfm?uri=oe-13-6-2019
  2. https://ieeexplore.ieee.org/abstract/document/4811119/
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