Laser Laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light "coherently". Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial
Blue laser Blue laser A blue laser is a laser that emits electromagnetic radiation with a wavelength between 360 and 480 nanometres, which the human eye sees as blue or violet. Blue beams are produced by helium-cadmium gas lasers at 441.6 nm, and argon-ion lasers at 458 and 488 nm. Semiconductor lasers with blue beams are typically based on gallium(III) nitride (GaN; violet color) or indium gallium nitride (often true blue in color, but also able to produce other colors). Both blue and violet lasers can also be constructed using frequency-doubling of infrared laser wavelengths from diode lasers or diode-pumped solid-state lasers.