Lasers made of sound. Call them… phasers.
Wired reveals the weird ways nanotechnologists are making sound behave like light… this time, by creating a Star Trek weapon in the lab:
Because laser is an acronym for “light amplification by stimulated emission of radiation,” these new contraptions – which exploit particles of sound called phonons – should properly be called phasers. Such devices could one day be used in ultrasound medical imaging, computer parts, high-precision measurements, and many other places.
“In our work, we got rid of this optical part,” said engineer Imran Mahboob of NTT Basic Research Laboratories in Japan, co-author of a paper describing the new sound lasers that appears Mar. 18 in Physical Review Letters. Because they need one less part, these new phasers “are much easier to integrate into other applications and devices.”
In traditional lasers, a bunch of electrons in a gas or crystal are excited all at the same time. When they relax back to their lower energy state, they release a specific wavelength of light, which is then directed with mirrors to produce a beam.
Sound lasers work on a similar principle. For Mahboob and his team’s phaser, a mechanical oscillator jiggles and excites a bunch of phonons, which relax and release their energy back into the device. The confined energy causes the phaser to vibrate at its fundamental frequency but with at a very narrow wavelength. The sound laser produces phonons at 170 kilohertz, far above human hearing range, which peters out around 20 kilohertz. The entire device is etched onto an integrated circuit that’s about 1 cm by 0.5 cm.
Don’t expect to set your phasers to stun just yet. Light has the advantage of being able to travel through a vacuum, so a laser beam can easily go from its origin point anywhere else, even through space. Phonons require a medium to travel through, which means the phaser waves are confined to their device for the time being.
So they’re probably using them for boring stuff like medical scanners and precise measurement. But soon. Set to stun.