In fiber-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i. This technique enables bidirectional communications over a. Wavelength division multiplexers are fundamental to the functioning and performance of integrated photonic circuits, with applications ranging from optical interconnects to sensing and quantum technologies. To begin with, we assume that we have the element parameters from a known process design kit (PDK). This makes it possible to scale capacity cost-effectively by using existing infrastructure more efficiently. Learn when to use WDM, how it works, and how open.