A sonic boom in the world of lasersJune 18, 2009It was an idea born out of curiosity in the physics lab, but now a new type of 'laser' for generating ultra-high frequency sound waves instead of light has taken a major step towards becoming a unique and highly useful 21st century technology. Scientists at The University of Nottingham, in collaboration with colleagues in the Ukraine, have produced a new type of acoustic laser device called a Saser. It's a sonic equivalent to the laser and produces an intense beam of uniform sound waves on a nano scale. The new device could have significant and useful applications in the worlds of computing, imaging, and even anti-terrorist security screening. Where a 'laser',(Light Amplification by the Stimulated Emission of Radiation), uses packets of electromagnetic vibrations called 'photons', the 'Saser' uses sound waves composed of sonic vibrations called 'phonons'. In a laser, the photon beam is produced by stimulating electrons with an external power source so they release energy when they collide with other photons in a highly reflective optical cavity. This produces a coherent and controllable shining beam of laser light in which all the photons have the same frequency and rate of oscillation. From supermarket scanners to DVD players, surgery, manufacturing and the defence industry, the application of laser technology is widespread. 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. Professor Anthony Kent from the University's School of Physics and Astronomy, says "While our work on sasers is driven mostly by pure scientific curiosity, we feel that the technology has the potential to transform the area of acoustics, much as the laser has transformed optics in the 50 years since its invention." The research team at Nottingham, with help from Borys Glavin of the Lashkarev Institute of Semiconductor Physics in the Ukraine, has won the immediate accolade of the publication of their paper on the Saser experiments in this month's leading Physics journal, Physical Review. The team has also won a grant of £636,000 from the Engineering and Physical Sciences Research Council to develop Saser technology over the next four years. University of Nottingham |
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| Related Sound Waves Current Events and Sound Waves News Articles Caltech scientists first to trap light and sound vibrations together in nanocrystal Researchers at the California Institute of Technology (Caltech) have created a nanoscale crystal device that, for the first time, allows scientists to confine both light and sound vibrations in the same tiny space. Berkeley researchers create first hyperlens for sound waves Ultrasound and underwater sonar devices could "see" a big improvement thanks to development of the world's first acoustic hyperlens. Created by researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), the acoustic hyperlens provides an eightfold boost in the magnification power of sound-based imaging technologies. New structure discovered in butterfly ears A clever structure in the ear of a tropical butterfly that potentially makes it able to distinguish between high and low pitch sounds has been discovered by scientists from the University of Bristol. Berkeley Lab Scientists' Computer Code Gives Astrophysicists First Full Simulation of Star's Final Hours The precise conditions inside a white dwarf star in the hours leading up to its explosive end as a Type Ia supernova are one of the mysteries confronting astrophysicists studying these massive stellar explosions. New type of sirolimus-eluting stent demonstrates superior results A new type of sirolimus-eluting stent (SES) successfully showed significantly greater neointimal suppression than the paclitaxel-eluting stent (PES) with greater vessel wall integrity surrounding the stent, confirming the finding of superiority of the SES over the PES stent for the trial's primary endpoint of in-stent late loss. APS Podcast Updates Research on Elephant Seismic Communication Caitlin O'Connell-Rodwell's insight that elephants 'talk' and 'listen' to vocalizations that they send through the ground grew from long hours of observation and experimentation, as well as her own in-depth knowledge of insects that communicate seismically. Scripps research scientists identify genetic cause for type of deafness A team led by scientists from The Scripps Research Institute has discovered a genetic cause of progressive hearing loss. A new cloaking method University of Utah mathematicians developed a new cloaking method, and it's unlikely to lead to invisibility cloaks like those used by Harry Potter or Romulan spaceships in "Star Trek." Instead, the new method someday might shield submarines from sonar, planes from radar, buildings from earthquakes, and oil rigs and coastal structures from tsunamis. Nanoelectronic transistor combined with biological machine could lead to better electronics If manmade devices could be combined with biological machines, laptops and other electronic devices could get a boost in operating efficiency. Dark Energy From the Ground Up: Make Way for BigBOSS Several ways have been proposed to examine dark energy, in hopes of finding out just what it is. One of them, "supernovae" for short, certainly works: it's how dark energy was discovered in the first place. Other independent techniques, such as weak gravitational lensing and baryon acoustic oscillation, also promise great power but are as yet unproven. More Sound Waves Current Events and Sound Waves News Articles |
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