Laser diodes are semiconductor devices that convert electricity into coherent light through stimulated emission in semiconductors. Made of materials like gallium arsenide, they have a structure with an active region, layers, and electrodes. When a forward bias is applied, electrons and holes recombine, emitting a laser beam known for high monochromaticity, directivity, and intensity.
In optical communication, they’re key light sources for high – speed, long – distance data transfer in fiber – optic systems. In optical storage, they read and write data on discs, enabling high – density storage. For laser processing, they’re used in cutting, welding, and surface treatment of materials. In laser display, they provide bright, high – color – gamut light for projectors and useful information in HUDs. In medicine, low – power ones are for therapy, while in imaging, they help obtain tissue structure details non – invasively.