What does "wavelength division multiplexing" (WDM) achieve?

Wavelength Division Multiplexing (WDM) is a crucial technology in fiber optics that allows for the simultaneous transmission of multiple signals over a single optical fiber. Each signal is transmitted at a different wavelength (or color) of light. This method effectively maximizes the capacity of the fiber by utilizing different wavelengths to carry distinct signals without interference.

By allowing multiple wavelengths to coexist within the same fiber strand, WDM significantly enhances the data-carrying capacity of optical networks, making it possible to transmit far more data than would be achievable using a single channel or wavelength. This is especially beneficial in environments where high bandwidth is essential, such as in telecommunications and data centers.

The other options do not accurately describe the primary function of WDM. Increasing the length of the fiber installation, rearranging fiber layout, or converting wavelengths to different frequencies are not key features or benefits of WDM technology. Instead, WDM is all about expanding capacity through the effective use of multiple wavelengths concurrently within the same fiber infrastructure.