A collaboration between Nottingham University and Lashkarev Institute of Semiconductor Physics in Ukraine report the development of an acoustic version of the laser, able to create highly focused beams of sound in the terahertz frequency range. Considering the impact that lasers had on optics and the world as a whole, the possibilities for an acoustic version must be wide ranging as well.
From Nottingham University:
The Saser mimics this technology but using sound, to produce a sonic beam of ‘phonons’ which travels, not through an optical cavity like a laser, but through a tiny manmade structure called a ‘superlattice’. This is made out of around 50 super-thin sheets of two alternating semiconductor materials, Gallium Arsenide and Aluminium Arsenide, each layer just a few atoms thick. When stimulated by a power source (a light beam), the phonons multiply, bouncing back and forth between the layers of the lattice, until they escape out of the structure in the form of an ultra-high frequency phonon beam.
A key factor in this new science is that the Saser is the first device to emit sound waves in the terahertz frequency range… the beam of coherent acoustic waves it produces has nanometre wavelengths (billionths of a metre). Crucially the ‘superlattice’ device can be used to generate, manipulate and detect these soundwaves making the Saser capable of widespread scientific and technological applications. One example of its potential is as a sonogram, to look for defects in nanometre scale objects like micro-electric circuits. Another idea is to convert the Saser beam to THz electromagnetic waves, which may be used for medical imaging and security screening. High intensity sound waves can also change the electronic properties of nanostructures so a Saser could be used as a high-speed terahertz clock to make the computers of the future a thousand times faster.
Press release from Nottingham University: A sonic boom in the world of lasers…