The technology used for high-speed data transmission over fiber optics is called Wavelength Division Multiplexing (WDM). WDM allows multiple data streams to be sent simultaneously over a single fiber optic cable by using different wavelengths (or channels) of laser light. This method significantly increases the bandwidth capacity of the fiber line, enabling greater data transfer rates. WDM is essential for modern telecommunications, allowing efficient use of existing fiber optic infrastructure to meet growing data demands.