DWDM is a laser technology used to increase bandwidth on existing fiber optic backbone networks. More precisely, the technology is to multiplex the tight spectral spacing of a single fiber carrier in a specified optical fiber in order to utilize the achievable transmission performance (for example, to achieve the minimum degree of dispersion or attenuation). In this way, With a given information transmission capacity, the total number of optical fibers required can be reduced. TSo what are the differences in the working principle, application and cost of DWDM transceivers?

Working Principle
Each fixed-wavelength DWDM module is designed with a specific wavelength, so the module can only be deployed in network nodes that require the corresponding wavelength. For example, the C21 wavelength SFP+ transceiver can only be used with the C21 wavelength port on the DWDM MUX. But using a tunable SFP+ optical fiber module, users can use the module to connect any port of the same DWDM MUX through an optical cable, because the wavelength of the tunable transceiver can be adjusted to adapt to different port wavelengths.

Application
Due to different working principles, standard DWDM optical modules are traditionally deployed in networks where there is almost no need to change or add channels. Although the tunable DWDM optical transceiver is conceived as a backup unit to adapt to the network that needs to change the wavelength as the business grows.

Cost
Indeed, the cost of a single fixed-wavelength transceiver is lower than a tunable DWDM module. But in the long run, tunable optics will reduce OPEX. For example, in a large 10G SFP+ DWDM system containing hundreds of nodes with different wavelengths, users must provide up to hundreds of backup standard DWDM SFP+ transceivers to avoid unnecessary failures, which will greatly increase operating costs. In this case, tunable optics can help reduce the need for DWDM SFP+ transceiver inventory, thereby reducing costs and maximizing network flexibility.