An Interstellar Communication laser of the First Federation era
Any device that emits a beam of electromagnetic radiation through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym in Old Earth first century English for "Light Amplification by Stimulated Emission of Radiation". The resulting light is highly coherent and so can be focused much more tightly and projected as a beam for much greater distances than radiation produced by other means.
Laser is a broad term, since there are many different ways of generating light in this way; two important methods of creating coherent beams are free-electron lasers and optical phased arrays. Using very large superconducting loop arrays, it is possible to induce laser emissions using stellar flares.
Sometimes lasers which produce radiation that is invisible to baseline human eyes are given alternative labels such as grasers (gamma ray laser) or masers (microwave ray laser). However these labels are rarely used, since unaugmented human baselines are very rare in most parts of the Terragen Sphere.
In the Current Era many systems use coherent light for various reasons, such as weaponry, communication and transportation. The Known Net, the God Web and many persons who travel using the Engenerator system use the network of powerful laser tranceivers known as the Lightways.