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Negative-index materials made easy
Richard wrote in message ...
Sam Wormley wrote: Ref: http://physicsweb.org/article/news/7/10/10 Physicists have observed negative refraction in an ordinary crystal for the first time. The material, made by researchers at the National Renewable Energy Laboratory in the US, could now be used to make lenses that do not reflect light and to study novel optical phenomena (Y Zhang et al. 2003 Phys. Rev. Lett. 91 157404). See: http://physicsweb.org/article/news/7/10/10 I prefer this one http://physicsweb.org/article/news/4/7/8/1 This is a majorly important result if true. There was some doubt such materials really were created: Negative reaction to negative refraction News: August 2002 "Physicists are involved in an unusually heated debate over the reality of a new kind of refraction and about the possibility of making perfect lenses. Edwin Cartlidge reports." http://physicsweb.org/article/world/15/8/8/1 Doubt cast on 'left-handed' materials 8 May 2002 "The surprising optical properties of so-called 'left-handed' materials have been thrown into doubt by physicists in Spain and the US. Researchers in Madrid say that claims that such materials could act as perfect lenses violate the principle of energy conservation. Meanwhile, physicists in Texas say that 'negative refraction' in left-handed materials would breach the fundamental limit of the speed of light. But other researchers in the field stand by their earlier discoveries and dispute the new results." http://physicsweb.org/article/news/6/5/4 I am puzzled by some claims for these materials: Nanotechnology creates ideal optical medium By R. Colin Johnson EE Times August 27, 2002 (11:12 a.m. ET) "Conventional lenses cannot focus light in an area smaller than the wavelength of the light, but with our nanomaterials you can focus light down much smaller than its own wavelength," said Shalaev. "These metallic nanostructures might even be able to detect a single molecule of a substance, which will never be possible for conventional optics." http://www.eetimes.com/story/OEG20020827S0019 Then we could use a "light microscope" to see objects smaller than the wavelength of visible light? I thought you need to have x-ray microscopes or electron microscopes for this. And you could make a perfect lens for a telscope? 'Metamaterial' holds promise for antennas, optics By R. Colin Johnson EE Times (05/11/01, 4:22 p.m. EDT) "Likewise, with a negative index of refraction, it should be possible to build a completely planar (flat) lens that nevertheless focuses light to a perfect geometric point. Instead of grinding the lens to specific convex or concave angles, metamaterials combined with traditional materials should be able to serve all lens needs with easy-to-make planar surfaces. "We think our principles can be extended to all wavelengths of electromagnetic radiation, eventually including visible light," said Smith." http://www.edtn.com/story/OEG20010430S0110 Bob Clark ------------------------------------------------------------- For email response, send to same userid as above, but append Hotmail.com instead of Yahoo.com. ------------------------------------------------------------- |
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