Optical module is the device of receiving luminous signal in the optical fiber transmission system, which is used to connect two electrical devices (such as server, switch, etc.) together with optical fiber. According to different types of applicable optical fibers, optical modules can be divided into single-mode optical modules and multi-mode optical modules.
About single-mode light module and multi-mode light module
As the name implies, single-mode light module is the light module used with single-mode fiber. LD or LED with narrow spectral line is used as the light source, which can transmit extremely high bandwidth data signal, so the transmission distance is very long. However, multi-mode optical module is used together with multi-mode optical fiber, which takes light-emitting diode or laser as light source, and the transmission distance is short.
The difference between single-mode light module and multi-mode light module
Transmission rate and distance - both single-mode and multi-mode optical modules can support 10G and 40G transmission, but the transmission distance is quite different. The maximum transmission distance of multi-mode optical module is about 550 m, while the transmission distance of single-mode optical module can reach 10 km, 40 km, 80 km or even more.
Price - the devices used in single-mode optical modules are twice as expensive as those used in multi-mode optical modules, so they are slightly more expensive than those used in multi-mode optical modules.
Performance - generally speaking, single-mode optical module can only be used with single-mode optical fiber, and multi-mode optical module can only be used with multi-mode optical fiber, not mixed.
Power consumption - the power consumption of multi-mode optical modules is lower than that of single-mode optical modules.
Use of single mode/multi-mode optical modules
When using single-mode/multi-mode optical modules, the following points should be noted:
Ensure that the optical modules at both ends of the fiber link have the same working wavelength; In order to reduce the packet loss rate, multi-mode optical module is used for short distance transmission and single-mode optical module is used for long distance transmission. Do not bend the optical cable between the optical modules to prevent excessive optical loss.
