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
Transistor laser that would normally be sent out through the electrical output. These electrons then undergo a process of radiative recombination, during which electrons and positively charged "holes" recombine in the base. While this process occurs in all transistors, it has an exceedingly short lifespan of only 30 picoseconds in the transistor laser, allowing for faster operation. Photons are then released through stimulated emission. Light bounces back and forth between reflective walls inside the 2.2 micrometer wide emitter that acts as a resonant cavity. Finally, light is emitted as a laser. The device was initially constructed out of layers of indium gallium