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 Sense of Direction A Sense of Direction A Sense of Direction is an album led by vibraphonist and composer Walt Dickerson recorded in 1961 and released on the New Jazz label. AllMusic awarded the album 4½ stars with its review by Steve Huey stating, "If it's a shade less challenging and inventive than "This Is Walt Dickerson!", "A Sense of Direction" compensates by making Dickerson's innovations more accessible and inviting". Down Beat reviewer Pete Welding wrote "if it is only slightly less adventurous than his initial recording, it is still an ardent collection -- primarily of ballads -- treated with unflagging invention and