Wavelength Division Multiplexing (WDM) is a technology used in fiber-optic communications to transmit multiple signals over a single optical fiber simultaneously. Here's a brief overview of how WDM works: 1. Wavelengths (Colors) of Light: WDM takes advantage of the fact that different wavelengths (colors) of light can be transmitted independently without interfering with each other. Each wavelength carries a separate data stream. 2. Multiplexing: In WDM, multiple signals, each operating at a distinct wavelength, are combined (multiplexed) onto a single optical fiber. This is typically achieved using a WDM multiplexer. 3. Transmission and Reception: The multiplexed signals are transmitted over the optical fiber to the receiving end. 4. Demultiplexing: At the receiving end, a WDM demultiplexer separates the different wavelengths back into individual signals. WDM comes in two main forms: - Coarse Wavelength Division Multiplexing (CWDM): CWDM uses fewer wavelengths (typically up to 1...