Principle and application of long distance optical module

As a photoelectric conversion device, an optical module is the most common product in an optical communication network. Among the characteristics of optical modules, transmission capacity is one of the most important and most concerned parameters. In addition, the transmission distance of the optical module is another core parameter that cannot be ignored. In different fields and links of optical communication network transmission, the characteristics of optical modules are also different.

According to the transmission distance of the optical module, it can be divided into three types: short-distance optical module, medium-distance optical module, and long-distance optical module. The long-distance optical module refers to an optical module with a transmission distance of 30 km or more. The need for long-distance transmission of network data.

In the actual use of the long-distance optical module, the maximum transmission distance of the module cannot be achieved in many cases. This is because a certain degree of dispersion occurs during the transmission of the optical signal in the optical fiber. To solve this problem, the long-distance optical module is adopted. Only one dominant wavelength is my DFB laser as the light source, thus avoiding the problem of dispersion.

Long-range optical modules are available in SFP optical modules, SFP+ optical modules, XFP optical modules, 25G optical modules, 40G optical modules, and 100G optical modules. Among them, the long-distance SFP+ optical module adopts the EML laser component and the photodetector component, which reduces the power consumption of the optical module and improves the accuracy; the long-distance 40G optical module adopts the driver and the modulation unit in the transmitting link, and receives The link uses an optical amplifier and a photoelectric conversion unit to achieve a maximum transmission distance of 80 km.

However, the transmission distance of the optical module is not as far as possible, and the appropriate solution should be taken when appropriate. The long-distance applications are mainly in the fields of server ports, switch ports, network card ports, security monitoring, telecommunications, Ethernet, and synchronous optical networks.