WDM (Wavelength Division Multiplexing)

WDM is a wavelength-multiplexing technique that lets you transmit multiple independent data channels through a single optical fiber simultaneously, each on a different wavelength of light.

How does WDM work?

At the transmitting end, a multiplexer combines signals from multiple lasers operating at different, precisely defined wavelengths into a single fiber. At the receiving end, a demultiplexer separates these wavelengths back into individual channels, routing them to dedicated receivers. Channels must be spectrally spaced apart appropriately to avoid crosstalk.

Applications

WDM is the foundation of modern long-haul telecommunications networks, metro networks, and data center interconnects, allowing the capacity of a single fiber to be multiplied without laying new infrastructure.

Related terms

DWDM

EDFA

Ring resonator