Sound amplification by stimulated emission of radiation despite the difference in phonon and exciton dimensionalities. Phonon laser action has been stated in a wide range of physical systems (e.g. semiconductors). A 2012 publication from the Department of Applied Physics in California Institute of Technology (Caltech), introduces a demonstration of a compound micro-cavity system, coupled with a radio-frequency mechanical mode, which operates in close analogy to a two level-laser system. This compound micro-cavity system can also be called ""photonic molecule"". Hybridized orbitals of an electrical system are replaced by optical supermodes of this photonic molecule while the transitions between their corresponding energy levels are induced by a phonon
Sound amplification by stimulated emission of radiation of a coherent amplification of THz sound. The THz stimulated phonon induced transitions between the electron superlattice states lead to this coherent amplification while processing a population inversion. An essential step towards coherent generation ("sasing") of THz sound and other active hypersound devices has been provided by this achievement of THz sound amplification. Generally, in a device where the threshold for "sasing" is achieved, the technique described by this proposed scheme could be used to measure the coherence time of the emitted hypersound. Sound amplification by stimulated emission of radiation Sound amplification by stimulated emission of radiation (SASER) refers to