Semiconductor lasers, also known as laser diodes, are devices that convert electrical energy into light through a process called electroluminescence. They are made from semiconductor materials, typically gallium arsenide or indium phosphide, which allow electrons to recombine with holes, releasing energy in the form of photons. This process occurs in a specially designed structure that amplifies the light, producing a coherent beam. These lasers are widely used in various applications, including optical communication, barcode scanners, and laser printers. Their compact size, efficiency, and ability to produce specific wavelengths make them essential in modern technology, enabling advancements in data transmission and imaging systems.