CWDM/DWDM wavelength division multiplexing equipment usage As people’s requirements for bandwidth are getting higher and higher, Dense Wavelength Division Multiplexing (DWDM) devices have made great progress in reducing costs, and are therefore more and more favored in the market. However, coarse wavelength division multiplexing equipment (CWDM) still has a higher price advantage in scenarios where connection rates are lower than 10G and short-distance transmission. In the network construction of low data rate, it is still the most feasible equipment at present. Hybrid transmission of CWDM/DWDM wavelength division multiplexing equipment CWDM wavelength division multiplexing equipment and DWDM wavelength division multiplexing equipment have their own advantages in OTN networks. The advantages of CWDM wavelength division multiplexing equipment are that it can use relatively low-cost distributed feedback lasers that do not require cooling and low prices. The passive filter, therefore the CWDM wavelength division multiplexing equipment system is currently widely used in the DWDM wavelength division multiplexing equipment system. Although CWDM technology can be used in DWDM systems to use cheaper optical modules, the CWDM channel spacing is relatively large, so the number of wavelengths available in the system will be reduced, and this also limits the transmission capacity of the system, so in a certain To some extent, it still can’t keep up with the non-hybrid DWDM wavelength division multiplexing equipment.