Laser
Laser - A device that can emit laser light. In 1954,
the first microwave quantum magnifier was built and a highly coherent microwave beam was obtained.
In 1958, A. L. Sholow and C. H. Towns applied the principles of microwave quantum amplifiers to the optical frequency range.
In 1960, T. H. Meyman and others produced the first ruby laser. In 1961 A. Javen et al. made a helium-neon laser. In 1962, R.N. Haller and others created a gallium arsenide semiconductor laser. In the future, there will be more and more kinds of lasers.
Divided by working medium, lasers can be divided into gas lasers, solid-state lasers, semiconductor lasers, and dye lasers.
Recently, free electron lasers have also been developed. High-power lasers are usually pulsed outputs.