What are the differences between single-mode optical modules and multi-mode optical modules and how to choose them?

With the rapid development of data centers and 5G applications, optical modules are gradually known by more and more people and have been widely used. As we all know, optical modules can be distinguished according to parameter types, such as the single-mode optical module and multi-mode optical module that we often mention. Do you know what single-mode and multi-mode mean in single-mode optical modules and multi-mode optical modules? What are the differences between single-mode optical modules and multi-mode optical modules? How to choose between different application situations? This article will tell you the difference between the two in detail and how to choose the question, you can read with questions.

1.What are single-mode optical modules and multi-mode optical modules?

Optical modules are divided into single-mode optical modules and multi-mode optical modules according to the applicable optical fiber types. The optical fiber wavelength of single-mode optical modules is 1310nm, 1550nm and WDM wavelength, while the optical fiber wavelength of multi-mode optical modules is 850nm or 1310nm. Currently, the optical fiber wavelength is mainly 850nm. Single-mode optical module and multi-mode optical module Single-mode optical module and multi-mode optical module refer to the transmission mode of optical fibers in the optical module. Therefore, they must be used together with single-mode optical fibers and multi-mode optical fibers. The linear diameter of single-mode optical fibers is 9/125μm, and the linear diameter of multi-mode optical fibers is 50/125μm or 62.5/125μm.

2.Difference between single-mode optical module and multi-mode optical module

In fact, the single-mode optical module and the multi-mode optical module are not only different in the type of fiber used, but also different in other aspects, as shown below:

①Transmission distance

Single-mode optical modules are often used for long-distance transmission, and the transmission distance of single-mode optical modules is different with different optical fiber wavelengths. The single-mode optical module with the optical fiber wavelength of 1310nm has a large loss but small dispersion during the transmission process, and the transmission distance is generally within 40km, while the single-mode optical module with the optical fiber wavelength of 1550nm has a small loss but large dispersion during the transmission process, and the transmission distance is generally more than 40km, and the farthest can be directly transmitted without a relay 120km. Multi-mode optical modules are often used for short-distance transmission, and the transmission distance is generally within 300 to 500m.

②Scope of application

From the above introduction, it can be seen that single-mode optical modules are often used in networks with long transmission distances and high transmission rates, such as metropolitan area networks and passive optical fiber networks, while multi-mode optical modules are often used in networks with short transmission distances and low transmission rates, such as data center equipment rooms and local area networks.

③Illuminant

The light source used by the single-mode optical module and the multi-mode optical module is different, the light source used by the single-mode optical module is a light emitting diode or laser, and the light source used by the multi-mode optical module is LD or LED.

④Power dissipation

The power consumption of single-mode optical modules is generally larger than that of multi-mode optical modules, but the power consumption of optical modules is mainly determined by factors such as the parameters, model and brand of the optical module, so the power consumption of single-mode optical modules with different parameters, models and brands will also be the same.

⑤Price

Compared with multi-mode optical modules, single-mode optical modules use a larger number of devices, the use of laser light source is more expensive, so the price of single-mode optical modules is higher than the price of multi-mode optical modules.

3.How to choose a single-mode optical module and a multi-mode optical module?

As mentioned above, single-mode optical modules and multi-mode optical modules are different in terms of transmission distance, application range, use of light source, power consumption and price, so the choice needs to be based on the actual application environment. For example, the metropolitan area network with a long transmission distance should choose a single-mode optical module, and the local area network with a short transmission distance should choose a multi-mode optical module. In simple terms, multi-mode optical modules should be selected in the network environment with many nodes, many connectors, many bends and large amounts of connectors and couplers, and single-mode optical modules should be selected in long-distance trunk lines.

4.Summarize

Through the above introduction, I believe you should have a clear understanding of single-mode optical modules and multi-mode optical modules. To avoid link failure, it is recommended that you choose a single-mode optical module or a multi-mode optical module according to your actual application situation. More importantly, it is best not to mix a single-mode optical fiber with a single-mode optical module.