Can YOU bend light backwards?!?

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Offline Mr Andrew

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Can YOU bend light backwards?!?
« on: 15/10/2007 20:55:47 »
http://www.physorg.com/news111593980.html

This is pretty exciting!...So many possibilities!  A negative index of refraction means that it would be possible to create a device that refracted at 180 degrees from the reflected light...possibly of use in quantum entanglement?!  Also by layering materials with negative and positive indices of refraction it would be possible to recover almost all of the light lost refracting through a mirror.  The image might not be clear but the intensity would diminish much slower.
--Life is the greatest experiment that any person will ever conduct.  It should be treated with the same scientific method as any other experiment.

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Offline syhprum

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Can YOU bend light backwards?!?
« Reply #1 on: 15/10/2007 22:03:55 »
I remember an article in the 'Wireless Engineer' in the fifties when materiel's with a negative refractive index at microwave frequencies were developed by embedding metal metal particles in plastic, this enabled a lens shaped as would normally diverge a beam to concentrate it
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lyner

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Can YOU bend light backwards?!?
« Reply #2 on: 16/10/2007 10:22:25 »
Quote
Also by layering materials with negative and positive indices of refraction it would be possible to recover almost all of the light lost refracting through a mirror
Looks like you are referring to the well known process of blooming lenses.
For this, you do not need a negative refractive index - just an intermediate value between that of the two layers on either side. Then you use good old interference filter techniques with quarter wave thicknesses.
Mirrors do not involve refraction, though - if you want a 'good' mirror as in a telescope, you silver the front surface. It's all reflection.
You can make good reflectors using interference filtering too . Then, again, total internal reflection is pretty good - SLR cameras, binoculars and even bicycle reflectors use it.