Sound amplification by stimulated emission of radiation

Sound Amplification by Stimulated Emission of Radiation (SASER) is a process that is analogous to the operation of a laser, but instead of light, it amplifies sound waves. The concept of SASER is based on the principle of stimulated emission, which is the fundamental principle behind laser technology. In a SASER, a medium (often a crystal or a gas) is energized to create a population inversion, where more particles are in an excited state than in the lower energy state.