Basic differences between single -mode optical fiber and multi -mode optical cable

Single-mode optical fiber and multi-mode optical fiber are two different types of optical fibers that are used in communication networks. They differ in terms of their core size, the number of modes they support, their bandwidth, and their distance limitations. In this article, we will discuss the basic differences between single-mode and multi-mode optical fibers.

Core Size

The most significant difference between single-mode and multi-mode optical fibers is their core size. Single-mode optical fibers have a smaller core diameter, typically between 8 to 10 microns, while multi-mode fibers have a larger core diameter, typically between 50 to 62.5 microns. The small core size of single-mode fibers allows them to transmit light in a single path or mode, which results in a much narrower pulse of light, with a higher bandwidth and longer transmission distances than multi-mode fibers.

Number of Modes

Multi-mode fibers support multiple modes of light propagation, meaning that light travels along different paths within the fiber core. These paths, known as modes, result in multiple pulses of light that arrive at different times at the receiving end, causing signal distortion, known as modal dispersion. Single-mode fibers, on the other hand, support only one mode of light propagation, which minimizes signal distortion, and leads to high-speed, long-distance transmission.

Bandwidth

Single-mode fibers have a higher bandwidth than multi-mode fibers. The smaller core diameter of single-mode fibers allows for higher bandwidth and longer transmission distances with lower signal attenuation, while multi-mode fibers have a lower bandwidth due to the multiple paths of light propagation that result in signal distortion and attenuation over long distances.

Distance Limitations

Single-mode fibers can transmit signals over longer distances than multi-mode fibers. Single-mode fibers can transmit signals over distances of up to 100 km or more, while multi-mode fibers are limited to shorter distances of up to a few kilometers due to the higher signal distortion and attenuation.

Equipment Compatibility

Single-mode and multi-mode fibers require different types of optical equipment for their operation. For instance, single-mode fibers require more expensive and precise equipment for their installation, splicing, and testing, while multi-mode fibers can be installed using simpler and less expensive equipment. Additionally, single-mode fibers require equipment that is specifically designed for their narrow bandwidth, while multi-mode fibers are compatible with a wide range of equipment.

Conclusion

In conclusion, single-mode and multi-mode optical fibers differ in terms of their core size, number of modes, bandwidth, distance limitations, and equipment compatibility. Single-mode fibers have a smaller core diameter and support only one mode of light propagation, which results in higher bandwidth and longer transmission distances with minimal signal distortion. Multi-mode fibers, on the other hand, have a larger core diameter and support multiple modes of light propagation, which results in lower bandwidth and shorter transmission distances with higher signal distortion. Choosing the right type of fiber for a communication network depends on the network's requirements for distance, bandwidth, and cost.