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
Quantum well laser cascade laser design. The story of the origin of the quantum well concept, its experimental verification, and the invention of the quantum well laser is told by Henry in more detail in the Foreword to "Quantum Well Lasers," ed. by Peter S. Zory, Jr. Quantum well lasers are important because they are the basic active element (laser light source) of the Internet fiber optic communication. Early work on these lasers focused on GaAs gallium arsenide based wells bounded by Al-GaAs walls, but wavelengths transmitted by optical fibers are best achieved with indium phosphide walls with indium gallium arsenide phosphide based