With the increasing demand for bandwidth, 100g network has developed rapidly. In order to meet the needs of 100g long-distance transmission, a variety of solutions have been produced: 4x25g NRZ series, 100g pam4 series and coherent series.
4*25g NRZ technology is the most mainstream 100g optical module solution at present, which is composed of four groups of transmitters and receivers. Under the demand of long-distance transmission, in order to save optical fiber resources, wavelength division multiplexing technology is usually used to multiplex four optical signals to one optical fiber for transmission. There are many kinds of 4x25g NRZ optical modules, including LR4 (10km) /er4 (40km) /zr4 (80km).
Among them, the cfp/cfp2/cfp4/qsfp28 packages are reduced in turn, and the power consumption is getting lower and lower under the same transmission distance. Customers can choose the product with the best power consumption according to the packaging and transmission distance required by the equipment.
100g coherent optical module is mainly used for line side optical transmission of 100g wavelength division system. Compared with other forms of line side optical modules, it has good OSNR performance, sensitivity, dispersion tolerance and DGD tolerance. DWDM wavelength division multiplexing technology with coherent modules is widely used in 100g man to meet the needs of high capacity and long distance.
Among them, in the data center field, due to the high-density and low-power connection requirements of the data center, qsfp28 optical modules with smaller packaging and power consumption are mostly used, and then they are selected according to the needs of transmission distance.
4x25g adopts NRZ scheme, with more mature technology and lower cost of single device, and can be directly interconnected with 25G optical modules. The 100g single wave optical module uses 100g pam4 modulation. By reducing the number of optical transmitters and receivers from 4 to 1, the optical complexity and cost are reduced compared with the 4x25g scheme. At the same time, the emergence of single wave 100g transmission technology has laid the foundation for the development of 400g (4x100g) Ethernet. When selecting, if it is a 25g/100g data center, the 4x25g scheme is selected; If it is a 100g/400g data center, the 100g pam4 scheme is selected.
The technology of 100g network will develop more and more mature. The 100g long-distance optical modules of rollback are complete. Customers can choose according to application requirements, transmission distance, network deployment, etc.