Sound amplification by stimulated emission of radiation a regime in which the phonon plays the role of Stokes wave. Stokes wave refers to a non-linear and periodic surface wave on an inviscid fluid (ideal fluid assumed to have no viscosity) layer of constant mean depth. For this reason it should be also possible to controllably switch between phonon and phonon laser regimes. Compound optical microcavity systems provide beneficial spectral controls. These controls impact both phonon laser action and cooling and define some finely spaced optical levels whose transition energies are proportional to phonon energies. These level spacings are continuously tunable by a significant adjustment of optical coupling.
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