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Scientists build the world's first anti-laser | Scientists build the world's first anti-laser |
(about 6 hours later) | |
Physicists have built the world's first device that can cancel out a laser beam - a so-called anti-laser. | Physicists have built the world's first device that can cancel out a laser beam - a so-called anti-laser. |
The device, created by a team from Yale University, is capable of absorbing an incoming laser beam entirely. | The device, created by a team from Yale University, is capable of absorbing an incoming laser beam entirely. |
But this is not intended as a defence against high-power laser weapons, the researchers said. | But this is not intended as a defence against high-power laser weapons, the researchers said. |
Instead they think it could be used in next-generation supercomputers which will be built with components that use light rather than electrons. | Instead they think it could be used in next-generation supercomputers which will be built with components that use light rather than electrons. |
Professor Douglas Stone and colleagues at Yale University had initially been developing a theory to explain which materials could be used as the basis of lasers. | Professor Douglas Stone and colleagues at Yale University had initially been developing a theory to explain which materials could be used as the basis of lasers. |
Strange lasers | Strange lasers |
Recent advances in laser design have resulted in a number of unusual devices that do not fit the traditional concept of a laser, Professor Stone explained. | Recent advances in laser design have resulted in a number of unusual devices that do not fit the traditional concept of a laser, Professor Stone explained. |
"So we were working on a theory that could predict what could be used to form a laser," he said. | "So we were working on a theory that could predict what could be used to form a laser," he said. |
That theory also predicted that instead of amplifying light into coherent pulses, as a laser does, it should be possible to create a device that absorbs laser light hitting it, said Professor Stone - an anti-laser. | That theory also predicted that instead of amplifying light into coherent pulses, as a laser does, it should be possible to create a device that absorbs laser light hitting it, said Professor Stone - an anti-laser. |
They have now succeeded in building one. | |
Their device focuses two lasers beams of a specific frequency into a specially designed optical cavity made from silicon, which traps the incoming beams of light and forces them to bounce around until all their energy is dissipated. | Their device focuses two lasers beams of a specific frequency into a specially designed optical cavity made from silicon, which traps the incoming beams of light and forces them to bounce around until all their energy is dissipated. |
In a paper published in the journal Science they demonstrated that the anti-laser could adsorb 99.4 per cent of incoming light, for a specific wavelength. | In a paper published in the journal Science they demonstrated that the anti-laser could adsorb 99.4 per cent of incoming light, for a specific wavelength. |
Light speed | Light speed |
Altering the wavelength of the incoming light means that the anti-laser can effectively be turned on and off - and that could be used in optical switches, Professor Stone told BBC News. | Altering the wavelength of the incoming light means that the anti-laser can effectively be turned on and off - and that could be used in optical switches, Professor Stone told BBC News. |
Building something which can absorb light over a wide range of wavelengths is pretty simple, said Professor Stone, but only doing so for a particular wavelength makes the anti-laser potentially useful in optical computing. | Building something which can absorb light over a wide range of wavelengths is pretty simple, said Professor Stone, but only doing so for a particular wavelength makes the anti-laser potentially useful in optical computing. |
The anti-laser's big advantage is that it is built using silicon, which is already widely used in computing. | The anti-laser's big advantage is that it is built using silicon, which is already widely used in computing. |
It would not, however, be much use as a laser shield, according to Professor Stone. | It would not, however, be much use as a laser shield, according to Professor Stone. |
"The energy gets dissipated as heat. So if someone sets a laser on you with enough power to fry you, the anti-laser won't stop you from frying," he said. | "The energy gets dissipated as heat. So if someone sets a laser on you with enough power to fry you, the anti-laser won't stop you from frying," he said. |
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