A new device uses a reflective cavity, a tiny bead and an electrode to create a laser beam of sound particles ten times more powerful and much narrower than other “phonon lasers” https://www.newscientist.com/article/2421719-sound-laser-is-the-most-powerful-ever-made/ A tiny, levitated bead is at the core of an unprecedentedly bright laser that shoots particles of sound instead of light. Just as a ray of light is made up of many particles called photons, sound consists of particle-like chunks called phonons. For several decades, researchers have been creating “phonon lasers” that output these particles in a narrow beam, similar to the way optical lasers emit photons. Now, Hui Jing at Hunan Normal University in China and his colleagues have created the brightest phonon laser yet.
