Wavelength Blocker: Basics and Function in Fiber Optics

This page explains the basics of a Wavelength Blocker, a crucial component used in fiber optic networks. We’ll delve into its function, particularly within Reconfigurable Optical Add-Drop Multiplexers (ROADMs).

Wavelength Blocker WB ROADM

The image above illustrates a Wavelength Blocker (WB) ROADM. Let’s explore the key features of this type of ROADM:

  • Dynamic Channel Equalization: It functions as a dynamic channel equalizer, ensuring signal strength consistency across different wavelengths.

  • ON/OFF Switch Functionality: The maximum attenuation setting provides a complete cutoff functionality, effectively acting as an ON/OFF switch for specific wavelengths.

  • ‘Broadcast and Select’ Architecture: It utilizes a ‘broadcast and select’ architecture, allowing any input wavelength to be routed to any output.

  • Long Haul Network Applications: It’s primarily used in long-haul fiber optic networks where signal degradation is a significant concern.

  • Channel Capacity: Typically handles around 80 channels with a spacing of approximately 50GHz between them.

  • Colored Ports: The ports are ‘colored,’ meaning they are designed for specific wavelengths.

  • Cost and Functionality: It tends to be expensive compared to other ROADM types, especially considering the limited functionalities offered.

  • Legacy Systems: Commonly found in older fiber optic systems.