Can Sound be used to controll the protesting mass?? ~ Technology Update

We people are very much known to the term LASER an acronym of "Light Amplification by the Stimulated Emission of Radiation."

Pink Laser

The traditional Light Amplification by the Stimulated Emission of Radiation (LASER) uses packets of electromagnetic vibrations called ‘photons’. The result is a continuous photon beam, created via stimulating electrons with an external power source; the release of energy (occurring as the electrons collide) is made in a highly reflective optical cavity. The coherent and controllable shining beam of laser light is due to the photons’ homogenous frequency and rate of oscillation. But Very few of us have heard about the term SASER that operates on principles remarkably similar to those of a laser.

Saser is the acronym for Sound Amplification by Stimulated Emission of Radiation.

The Saser mimics the laser technology, but instead of light waves it employs sound waves, and instead of photons it sends phonons. In addition, instead of sending waves through an optical cavity, the sonic Saser travels through a tiny structure called a ‘superlattice’. This structure is made out of 50 super-thin sheets of two alternating semiconductor materials, Gallium Arsenide and Aluminum Arsenide. In order to achieve the exact effect, each layer must be as thin as air – just a few atoms thick. When the phonons are inside the superlattice, they bounce, multiply and eventually escape in the form of an ultra-high frequency photon beam.

Previous researches have tried to develop sound-emitting devices, but this is the first time a device emits sound waves in the terahertz frequency range. As for the beam itself, it consists of coherent acoustic waves, produced at nanometer wavelengths. The scientific and technological applications vary; one example of the Saser’s potential is the sonogram, a device that can scan for defects in nanometer scale objects like micro-electric circuits.
The main function of a saser or phonon laser is to produce a highly coherent beam of ultrasound sasers are of much current fundamental and technological interest.

In the 50 years since Theodore Maiman demonstrated the first working laser, physicists have labored to build devices capable of controlling sound waves in the same way that optical lasers manipulate light. This year, two teams of researchers announced the development of successful sound-based lasers, or “sasers.”

Optical lasers use quantum effects to produce an intense beam of light of a single frequency, or color. The big challenge in translating that capability to sound has been finding an analogous way to amplify just one sonic frequency. Physicist Tony Kent and his colleagues at the University of Nottingham in England managed to create such an amplifier from a thin, layered lattice made of two semiconductors, gallium arsenide and aluminum arsenide. The resulting saser can build up an intense, pure sound wave at a specific frequency in the terahertz range (far, far above the limit of human hearing) for a few billionths of a second.

Researchers’ next goal is to lengthen the duration of the sonic amplification. Caltech physicist Kerry Vahala and his group are making progress in that direction with a different type of acoustic laser. Their technique relies on firing an optical laser at tiny glass membranes to amplify sound. Unlike the Nottingham saser, Caltech’s device can run continuously, but it operates at a slower speed of 50 megahertz. Vahala is working to boost that frequency into higher ranges, which will probably be more useful for acoustic imaging.

Other potential applications for sasers include detecting defects in microscopic structures and improving signal processing in semiconductor chips, the scientists say. Vahala has no doubt that once the technology matures, it will quickly find all kinds of other uses as well. After all, optical lasers now perform eye surgery, scan groceries, and play movies off DVDs. “But when the laser first came out,” Vahala says, “no one had the foggiest idea what to do with it.”

Using sound beams to control crowds isn't new, but never before have systems been able to create sounds reaching terahertz frequencies, earning them the name "saser."

Signaling the dawn of the true saser era, physicists from the UK and Ukraine have broken this apparently elusive terahertz sound barrier. Unlike lasers that shoot photons in a tight beam of light, sasers are able to emit dispersed vibrations in high frequences of sound waves, creating nausea and confusion when used on humans.

The latest and most powerful saser has proven to be able to produce phonons—some quantum-level measurement of vibration that could (one day) be used to cure cancer or shoot enemies, among other things—in distant objects. These early tests of the saser reveal its potential of one day (we think) being able to make someone explode, from the inside out, using just a handful of terahertz—similar to what would happen to your brain at a Hannah Montana concert.