what is a laser

A laser is a device that emits a beam of coherent light through an optical amplification process. The word "laser" is an acronym that stands for Light Amplification by Stimulated Emission of Radiation. Lasers produce a very narrow beam of light, which is different from a light bulb or a flashlight. The light waves in a laser beam are coherent, meaning they are moving in the same direction at the same wavelength. Lasers have many types, including gas lasers, fiber lasers, solid-state lasers, dye lasers, diode lasers, and excimer lasers. All of these types share a basic set of components, including a gain medium capable of sustaining stimulated emission, an energy source to pump the gain medium, a total reflector to reflect energy, a partial reflector, and a laser beam output. Lasers have many uses, including precision tools, cutting through diamonds or thick metal, reading information from disks, bar code scanning, surgical procedures, and manufacturing processes such as cutting, engraving, drilling, and marking a broad range of materials.