Most powerful 'sound laser' to shake up acoustics - tech - 15 June 2009 - New Scientist

Most powerful 'sound laser' to shake up acoustics - tech - 15 June 2009 - New Scientist:

"Most powerful 'sound laser' to shake up acoustics

16:39 15 June 2009 by Colin Barras

Half a century since the first working laser kick-started a technological revolution in the field of optics, a new device promises to do the same for acoustics. UK and Ukrainian physicists have built the first 'saser', or sound laser, able to generate terahertz-frequency sounds.

A laser produces photons that travel in a tight beam instead of dispersing outwards like a regular beam of light. A saser achieves the same for sound waves, says Tony Kent at the University of Nottingham, UK.

Although it's not the first saser ever constructed, it is the first able to produce beams at terahertz frequencies, much higher even than those used for medical ultrasound imaging. Terahertz sound may be largely a curiosity today, says Kent, but being able to produce it in controllable beams could unleash new ideas and applications.

'Fifty years ago many eminent scientists said that light amplification by the stimulated emission of radiation [lasers] was no more than a scientific curiosity,' says Kent, but lasers are now used for everything from digital storage and cancer treatment to weaponry."