A Semiconductor Optical Amplifier (SOA) is a device that amplifies optical signals using semiconductor materials. It works by injecting electrical current into the semiconductor, which stimulates the emission of photons, thereby increasing the intensity of the light signal. SOAs are commonly used in fiber optic communication systems to boost signal strength over long distances. SOAs are compact and can be integrated into various optical systems, making them versatile for applications like telecommunications and data centers. They offer advantages such as low power consumption and the ability to operate over a wide range of wavelengths, enhancing their utility in modern optical networks.