Erbium-Doped Fiber is a type of optical fiber that has been infused with the rare earth element erbium. This doping process enhances the fiber's ability to amplify light signals, making it essential for long-distance telecommunications. The unique properties of erbium allow it to efficiently amplify signals in the 1550 nm wavelength range, which is commonly used in fiber optic communication. The use of erbium-doped fibers is crucial in modern fiber optic networks, as they help maintain signal strength over long distances without the need for electrical repeaters. This technology supports high-speed internet, television, and telephone services, contributing to the overall efficiency of data transmission.