Physicists in Germany have devised a new way to make metamaterials that could be used to boost the resolution of optical microscopes. The technique involves depositing alternating layers of semiconductor and metal on a flat surface and then rolling up the layers into a tube that resembles a hollow Swiss or jelly roll.
Because the metamaterial is a cylinder, the path taken by light moving outward along a radius of the tube (and therefore the permittivity) is very different the path taken by light moving tangentially to the layers. For light at the plasma frequency radial light experiences a relatively large permittivity, while light moving tangentially experiences a relatively small permittivity. As a result, the light is focussed into the radial direction. ...
Capturing evanescence
This means that the tube could be used as a hyperlens, which captures "evanescent" light from tiny objects and focuses it into an image that can be further magnified by conventional optics. Evanescent light can resolve features much smaller than wavelength-limited conventional optics – however, it does not travel far from the surface of the object and cannot be seen by a conventional microscope.
Mendach told physicsworld.com that the magnification of the tubes was not great enough to confirm that they could be used as hyperlenses. Instead, they fed their optical measurements into computer simulations, which suggested that they could.
According to Mendach, the magnification can be boosted by creating tubes with a greater ratio of outer and inner diameter – something that the team is working on, along with an invisibility cloak.
via Rolled-up metamaterial could act as hyperlens - optics.org.
The back up Blog of the real Xenophilius Lovegood, a slightly mad scientist.
Sunday, October 25, 2009
Rolled-up metamaterial could act as hyperlens
Hyperlensing is a neat trick. For more on the limits of how light works when used to view very small objects, check out my Rife article.
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