DWDM

ISP & telecom

Stands for: Dense Wavelength Division Multiplexing

Dense Wavelength Division Multiplexing - many independent light colors down one fiber. The reason a single strand can carry terabits and the backbone of every long-haul network.

DWDM packs dozens of tightly-spaced wavelengths (the ITU-T G.694.1 grid in the C-band, 100/50 GHz spacing and now flexible grids) onto one fiber pair, each lambda its own independent link. Erbium-doped fiber amplifiers made it practical by boosting all channels at once without electronics, and coherent optics pushed each wavelength from 10G to 100G, 400G and beyond. It is how submarine cables, national backbones, and metro rings scale - and why leasing 'a lambda' is a product. Its coarser sibling CWDM spaces channels wider for cheaper short-haul gear.

Also known as: dwdm, wdm, cwdm, wavelength division, lambda

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