WDM is a three-letter abbreviation with multiple meanings, as described below:

Survivable WDM mesh networks
Survivable WDM mesh networks. II. Restoration
Survivable WDM mesh networks. II. Restoration
Survivable WDM mesh networks. Part I-Protection
Survivable WDM Mesh Networks, Part I-Protection
Traffic grooming in an optical WDM mesh network
Control architecture in optical burst-switched WDM networks
Control architecture in optical burst-switched WDM networks
QoS performance of optical burst switching in IP-over-WDM networks
A Review of Routing and Wavelength Assignment Approaches for Wavelength-Routed Optical WDM Netrowks