laser

Definition

Light Amplification by Stimulated Emission of Radiation. Optical electronic device that generates an intense (very narrow) beam of single color (monochromatic) light by pumping (amplifying) photons with more energy through collisions with other photons. Laser beams can travel vast distances without dispersion and can carry enormous amounts of energy (100 million watts per square centimeter, and more). Different types of lasers are used for purposes as diverse as CD/DVD writing and reading, communications, land mapping, metal cutting and welding, surgery, and anti-missile defenses.