Sound amplification by stimulated emission of radiation of the laser. In a SASER device, a source (e.g., an electric field as a pump) produces sound waves (lattice vibrations, phonons) that travel through an active medium. In this active medium, a stimulated emission of phonons leads to amplification of the sound waves, resulting in a sound beam coming out of the device. The sound wave beams emitted from such devices are highly coherent. The first successful SASERs were developed in 2009. Instead of a feedback-built wave of electromagnetic radiation (i.e., a laser beam), a SASER delivers a sound wave. SASER may also be referred to as "phonon laser",
A Sound of Thunder (band) feels like it flies by in hail of harmony, wailing vocals, and addictive riffs. Despite the wealth of melody and energetic feel of the record, A Sound of Thunder did not short change the listener on substance or depth. Every track feels like a mini-masterpiece unto itself. Each spin through the album reveals more details and invites another journey through. Every individual performance is on point, and while they all shine on their own, it is in the collective that they ascend to something greater. While the band may not see it as such, It Was Metal is A Sound