DWDM

Dense Wavelength-Division Multiplexing (DWDM) is a technology which multiplexes a large number of optical carrier signals onto a single optical fibre by using different wavelengths (i.e., colors) of laser light.

ITU has standardized a channel spacing grid for DWDM (ITU-T G.694.1) using the wavelengths from approximately 1530 to 1565nm with a channel spacing of 100Ghz (0.8nm) or 50GHz (0.4nm).