The full form of DWDM is Dense Wavelength Division Multiplexing,

• Dense wavelength division multiplexing (DWDM) is a fiber-optic technology that increases the bandwidth capacity of fiber cable.
• Dense wavelength division multiplexing combines data from different sources on a single optical fiber by carrying each signal on a separate wavelength of light.
• With dense wavelength division multiplexing, up to 80 data channels can be multiplexed into a single optical fiber. Each channel can carry 2.5 Gbps, enabling bandwidth of 200 billion bits per second on one fiber cable.
   

Dense wavelength division multiplexing has been a part of fiber optics for more than 20 years. Yet for many, the definition and benefits of this essential technology are a bit vague. What is dense wavelength division multiplexing, exactly, and what advantages does it offer an organization? Here’s a brief introduction to “What is dense wavelength division multiplexing?” that answers these questions and others.