Amplification of microwave radiation by substances not in thermal equilibrium

This paper briefly discusses the possibility of obtaining coherent microwave radiation from crystals and gases. It will be shown that it is possible to obtain coherent microwave radiation by such methods, provided that a certain non equilibrium energy distribution is first produced. Methods are discussed for producing such a distribution. The amount of amplification which can be produced by such methods is very small Tinder ordinary circumstances and does not appear to be able to compete with other methods. The method may have certain special applications.