Explore 14 top manufacturers and suppliers of Fiber Optic Dense Wavelength Division Multiplexers in our comprehensive photonics buyers' guide. As 5G, cloud, and AI workloads soar, DWDM is no longer a telecom-only domain—it's a digital economy enabler. This technique enables bidirectional communications over a. Corning's dense wavelength division multiplexers (DWDMs) are integrated optical modules that combine, or multiplex, and separate, or demultiplex multiple optical signals of different wavelengths in a single fiber.