Multi-mode optical module VS Single-mode optical module

The optical module is a device for receiving and receiving optical signals in the optical fiber transmission system and is used to connect two electrical port devices (such as servers, switches, etc.) together with optical fibers. According to different types of applicable optical fibers, optical modules can be divided into single-mode optical modules and multi-mode optical modules. This tutorial will introduce the differences between these two types of optical modules in detail.

About single-mode optical modules and multi-mode optical modules

As the name implies, a single-mode optical module is an optical module used with a single-mode optical fiber. It uses LD or LED with a narrow spectral line as the light source, and can transmit data signals with extremely high bandwidth, so the transmission distance is very long. The multimode optical module is used together with the multimode optical fiber, and the light-emitting diode or laser is used as the light source, and the transmission distance is relatively short.

The differences between single-mode optical modules and multi-mode optical modules are listed in detail below:

1. Transmission rate and distance—both single-mode optical modules and multi-mode optical modules can support 10G and 40G transmission, but their transmission distances are quite different. The maximum transmission distance of the multi-mode optical module is about 550 m, while the transmission distance of the single-mode optical module can reach 10 km, 40 km, 80 km or even farther.

2. Price—The components used in the single-mode optical module are twice that of the multi-mode optical module, so its price is slightly more expensive than the multi-mode optical module.

3. Performance—Generally speaking, single-mode optical modules can only be used with single-mode optical fibers, and multi-mode optical modules can only be used with multi-mode optical fibers and cannot be mixed.

4. Power Consumption—The power consumption of multi-mode optical modules is lower than that of single-mode optical modules.

Tips for using single-mode/multi-mode optical modules

When using single-mode/multi-mode optical modules, you should pay attention to the following points:

Ensure that the optical modules at both ends of the fiber link work at the same wavelength; In order to reduce the packet loss rate of data, use multi-mode optical modules for short-distance transmission applications, and single-mode optical modules for long-distance transmission applications; do not bend the optical cables between optical modules significantly, To prevent excessive fiber loss.