Lasers in acoustics

The thirtieth anniversary of the discovery of the laser is celebrated in 1990. Modern lasers emit in a wide range of wavelengths and major progress has been made in the development of tunable dye lasers, as well as of gas and solid-state lasers. Semiconductor lasers are now mass-produced and represent the smallest was well as the most reliable components of quantum electronics.1 In the last 30 years lasers have become generally accepted in science and technology, as well as in industry, medicine, and protection of the environment. In practically all applications the introduction of lasers has led to or will lead to revolutionary changes.2