Editing Wavelength-division multiplexing (section)

===CWDM Applications===
CWDM is being used in [[cable television]] networks, where different wavelengths are used for the ''downstream'' and ''upstream'' signals. In these systems, the wavelengths used are often widely separated. For example, the downstream signal might be at 1310&nbsp;nm while the upstream signal is at 1550&nbsp;nm.{{Citation needed|date=February 2019}}

The [[10GBASE-LX4]] {{nowrap|10 Gbit/s}} [[physical layer]] standard is an example of a CWDM system in which four wavelengths near 1310&nbsp;nm, each carrying a {{val|3.125|u=Gbit/s}} data stream, are used to carry {{nowrap|10 Gbit/s}} of aggregate data.<ref name=":2">{{Cite journal|last=Hornes|first=Rudy. L|year=2008|title=The Suppression of Four-Wave Mixing by Random Dispersion|jstor=40233639|journal=SIAM Journal on Applied Mathematics|volume=69|issue=3 |pages=690–703|doi=10.1137/070680539 }}</ref>

Passive CWDM is an implementation of CWDM that uses no electrical power. It separates the wavelengths using passive optical components such as bandpass filters and prisms. Many manufacturers are promoting passive CWDM to deploy fiber to the home.{{Citation needed|date=February 2019}}