Laser Technologies and Future Applications

A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word laser is an acronym that originated as an acronym for light amplification by stimulated emission of radiation. The first laser was built in 1960 by Theodore Maiman at Hughes Research Laboratories, based on theoretical work by Charles H. Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light that is coherent. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. It also allows a laser beam to stay narrow over great distances (collimation), a feature used in applications such as laser pointers and lidar (light detection and ranging). Lasers can also have high temporal coherence, which permits them to emit light with a very narrow frequency spectrum. Alternatively, temporal coherence can be used to produce ultra-short pulses of light with a broad spectrum but durations as short as a femtosecond.