Wavelength Division Multiplexing (WDM) is a technique in fiber-optic communication systems that enables multiple optical signals with different wavelengths to be combined, transmitted, and separated over a single optical fiber. The article explains the fundamental principle and its. Corning's R&D scientists are constantly searching for new ways to improve wavelength division multiplexing (WDM) technology. They are a cost effective method to expand the capacity of existing fiber optic cables. Learn when to use WDM, how it works, and how open.