The tell-tale signature of most lasers used in everyday applications—from bar-code scanners to pen-size pointers—is a bright red glow. The color is determined by the lights wavelength, and most lasers emit at only one wavelength. Now a new report published in the current issue of the journal Nature describes a light source measuring only tens of millimeters across that changes color according to temperature.
To make the new laser, Diederik Wiersma and Stefano Cavalieri of the European Laboratory for Non-linear Spectroscopy in Florence, Italy, manipulated the properties of a so-called random laser. Random lasers use light-diffusing material—often in the form of a fine powder—to trap light within the system long enough for amplification to occur. The more the light scatters, the larger the overall gain of the laser.
The researchers placed a liquid crystal inside a random laser source. By heating the crystal and changing the arrangement of its atoms, they could control the amount of light scattering within the laser and hence the color of emitted light. This so-called tunable random laser, the authors conclude, may one day find application as a source in active displays and temperature-sensitive screens or as a remote temperature-sensing device.
Sarah Graham | Scientific American
Stanford researchers develop a new type of soft, growing robot
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Team develops fast, cheap method to make supercapacitor electrodes
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Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
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What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
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