DWDMsystem

DWDMsystem is a dense wavelength-division multiplexing system, a fiber-optic communications technology that transmits multiple data streams on a single fiber by using different wavelengths of light. Each channel is modulated with its own data, allowing a very high aggregate data rate over a single fiber.

A typical DWDMsystem includes transmitters, a multiplexer to combine channels, the optical fiber, a demultiplexer, and receivers. In modern networks, add-drop multiplexers (ROADMs) enable flexible routing of channels at intermediate nodes. Optical amplifiers, such as EDFAs and Raman amplifiers, compensate loss along the link. Dispersion management and, increasingly, coherent detection are used to improve reach and spectral efficiency.

DWDM channels are spaced on ITU-T standard grids, commonly 50 GHz or 100 GHz, though tighter spacing is used in ultra-dense systems. The bandwidth scaling is achieved by increasing the number of channels, using higher order modulation, and employing coherent technology.

Applications include long-haul telecommunications, metro networks, and data center interconnects, enabling terabit-per-second-class capacity on a single fiber. Operating considerations include cost, design complexity, amplification and nonlinear effects, and the need for network management and protection switching.