Wavelength Selective Switch (WSS) in Fiber Optics Explained

This page explains the basics of WSS used in the fiber optic domain.

The full form of WSS is Wavelength Selective Switch. It’s an optical device, a circuit pack that performs the following functions:

• Wavelength Switching
• Optical Power Control for ROADM (Reconfigurable Optical Add Drop MUX)
• Optical Power Control for Wavelength Switch Nodes.

Figure depicts a WSS of a degree-4 node type.

For mesh connectivity, a 1 x 5 WSS with a degree-4 node is typically used. It supports ring-to-ring interconnection. Three WSS units are required for each degree to support mesh connectivity as well as colorless ADD/Drop ports.