It is a method for combining multiple data signals onto a single optical fiber by assigning each data stream a distinct light wavelength. 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. The chapter begins with a quick historical account of the origin of optical communication and its exponential growth following the invention of erbium oped fiber amplifier (EDFA) leading to the widespread adoption of WDM. This makes it possible to scale capacity cost-effectively by using existing infrastructure more efficiently. Read on to learn the fundamentals of this useful technology. To begin with, we assume that we have the element parameters from a known process design kit (PDK).
