Which technology enables the addition of new wavelengths in a fiber-optic network?

IPoDWDM describes an architecture for integrating IP routers directly with DWDM systems, rather than the underlying technology for adding wavelengths.

Coarse Wavelength Division Multiplexing (CWDM) also adds wavelengths but is typically limited to fewer channels and shorter distances compared to the high-capacity expansion offered by DWDM.

Dense Wavelength Division Multiplexing (DWDM) is a technology that allows multiple optical carrier signals, each at a different wavelength, to be multiplexed onto a single optical fiber. It is the primary technology enabling the addition of new wavelengths to significantly increase the capacity of fiber-optic networks.

A Reconfigurable Optical Add/Drop Multiplexer (ROADM) is a component used within DWDM systems to dynamically manage and route individual wavelengths, not the core technology for adding them.