As an optical conversion device, optical module is the most common product in the optical communication network. Among the characteristics of optical modules, transmission capacity is the most central and most concerned parameter. In addition, the transmission distance of optical modules is another core parameter that cannot be ignored. In different areas and links of optical communication network transmission, the characteristics of optical modules are also different.
According to the different transmission distance of optical modules, they can be divided into three types: short-distance optical modules, medium-distance optical modules, and long-distance optical modules, of which long-distance optical modules refer to optical modules with a transmission distance of 30 km or more, which can meet the needs of long-distance network data transmission.
In the actual use of long-distance optical modules, in many cases can not reach the maximum transmission distance of the module, this is because the optical signal in the fiber transmission process will appear a certain degree of dispersion, in order to solve this problem, long-distance optical modules use only one main wavelength is I DFB laser as the light source, so as to avoid the problem of dispersion.
Among these types of SFP optical modules, SFP+ optical modules, XFP optical modules, 25G optical modules, 40G optical modules and 100G optical modules, there are long-range optical modules. Among them, the long-distance SFP+ optical module uses EML laser components as well as optical detector components to reduce the power consumption of the optical module while improving the accuracy; the long-distance 40G optical module uses drivers and modulation units in the transmitting link, and optical amplifiers and photoelectric conversion units in the receiving link to achieve a maximum transmission distance of 80km.
However, the transmission distance of the optical module is not the farther the better, and a suitable solution should be taken when and where necessary. The long-distance applications are mainly in the field of server ports, switch ports, network card ports, security monitoring field , telecommunication field, Ethernet, synchronous fiber optic networks, etc.
