An optical amplifier is a device that boosts the strength of optical signals, which are used in fiber optic communication. By amplifying these signals, optical amplifiers help maintain signal quality over long distances, reducing the need for frequent signal regeneration. They work by using a medium, such as erbium-doped fiber, that can amplify light when pumped with energy. These amplifiers are essential in modern telecommunications, enabling high-speed data transmission across vast networks. They can operate on various wavelengths, making them versatile for different applications. Overall, optical amplifiers play a crucial role in enhancing the performance of fiber optic systems.