How soon before we can buy better than diffraction limited optics?

[g__day]

It was interesting reading in Nov 2006 Australian Scientist that metamaterials with a negative refraction index promises better than differaction limited view - initially to half the wave length of light, in the near future.

Has anyone read much about this and have any idea how far this idea (at the prototyping stage) is from commercial production?

About 2 years ago I read research in to nano-tube Hartman masks offerred possibilities - but this seemed far more promising!

http://www.ee.duke.edu/~drsmith/negative_index_about.htm

[xelasnave]

Very interesting proposition G Day It is hard to imagine that any material could have a negative index I would love to read more do you have a link to anything showing the materials that are able to produce negative refraction?. I assume this would mean in the practical sense that one would use a concave lens as an objective in place of the convex objective lens in a refractor:shrug: . If thats the case better performance would come from less "glass" for the light to travel thru I suppose??
alex
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[g__day]

Google it and you'll find hundreds of links and alot of controversy over the last 4 years. Metamaterials moved from theory to reality - but where the could bounce visible light with negative refraction index was a very recent advance, with compelling benefits.

I'll search some more...

[g__day]

http://networking.engadget.com/2006/05/02/japanese-reseachers-invent-completely-transparent-material/2

http://en.wikipedia.org/wiki/Metamaterial

http://betterhumans.com/blogs/brianwang/archive/2006/06/29/8656.aspx

or

http://www.sciencedaily.com/releases/2007/01/070104144655.htm

Source:Ames Laboratory (http://www.external.ameslab.gov/)Date:January 9, 2007
Metamaterials Found To Work For Visible Light

Science Daily (http://www.sciencedaily.com/) — For the first time ever, researchers at the U.S. Department of Energy's Ames Laboratory have developed a material with a negative refractive index for visible light. Ames Laboratory senior physicist Costas Soukoulis, working with colleagues in Karlsruhe, Germany, designed a silver-based, mesh-like material that marks the latest advance in the rapidly evolving field of metamaterials, materials that could lead to a wide range of new applications as varied as ultrahigh-resolution imaging systems and cloaking devices.

The discovery, detailed in the Jan. 5 issue of Science and the Jan. 1 issue of Optic Letters, and noted in the journal Nature, marks a significant step forward from existing metamaterials that operate in the microwave or far infrared -- but still invisible --regions of the spectrum. Those materials, announced this past summer, were heralded as the first step in creating an invisibility cloak.
Metamaterials, also known as left-handed materials, are exotic, artificially created materials that provide optical properties not found in natural materials. Natural materials refract light, or electromagnetic radiation, to the right of the incident beam at different angles and speeds. However, metamaterials make it possible to refract light to the left, or at a negative angle. This backward-bending characteristic provides scientists the ability to control light similar to the way they use semiconductors to control electricity, which opens a wide range of potential applications.


"Left-handed materials may one day lead to the development of a type of flat superlens that operates in the visible spectrum," said Soukoulis, who is also an Iowa State University Distinguished Professor of Liberal Arts and Sciences. "Such a lens would offer superior resolution over conventional technology, capturing details much smaller than one wavelength of light to vastly improve imaging for materials or biomedical applications," such as giving researchers the power to see inside a human cell or diagnose disease in a baby still in the womb.
The challenge that Soukoulis and other scientists who work with metamaterials face is to fabricate them so that they refract light at ever smaller wavelengths. The "fishnet" design developed by Soukoulis' group and produced by researchers Stefan Linden and Martin Wegener at the University of Karlsruhe was made by etching an array of holes into layers of silver and magnesium fluoride on a glass substrate. The holes are roughly 100 nanometers wide. For some perspective, a human hair is about 100,000 nanometers in diameter.

"We have fabricated for the first time a negative-index metamaterial with a refractive index of -0.6 at the red end of the visible spectrum (wavelength 780 nm)," said Soukoulis. "This is the smallest wavelength obtained so far."

While the silver used in the fishnet material offers less resistance when subjected to electromagnetic radiation than the gold used in earlier materials, energy loss is still a major limiting factor. The difficulties in manufacturing materials at such a small scale also limit the attempts to harness light at ever smaller wavelengths.

"Right now, the materials we can build at THz and optical wavelengths operate in only one direction," Soukoulis said, "but we've still come a long ways in the six years since negative-index materials were first demonstrated."

"However, for applications to come within reach, several goals need to be achieved," he added. "First, reduction of losses by using crystalline metals and/or by introducing optically amplifying materials; developing three-dimensional isotropic designs rather than planar structures; and finding ways of mass producing large-area structures."

[robagar]

Can you imagine just how cloudy it's going to be when these are released? :p

[xelasnave]

thanks G day
alex

[g__day]

Alex

It seems to be almost more the material structure then the material itself. They are boring millions of tiny, tiny holes thru a substance to create this impressive effect - nano tubes a thousandth the size of the diameter of a human hair.


Lens shape could be flat! Its the tubes that do the work. Imagine either a static piece of glass that looked like window pane but was almost a perfect - far better than difraction limited lens. Secondly I read that more exotic materials and composite structures may have dynamically alterably refractive index. Imagine a flat 3 metre cylinder of glass that could act as a perfect parabolic mirror, alterable in a split second between F1 up to F30 , depending on how you run a current through it - wouldn't that be something!

[xelasnave]

Yes G day I have been thinking about the possibilities and I now also ask.... when and where can we buy one:D . Imagine the possibility of having one perfect eye piece ... mmm more batteries I guess.
Spent until 4 am reading everything I could find and I now know so much less than when I started...;)
alex

[xelasnave]

Talk about the more you read the less you understand, can I ask this question G day.. do you see the rearrangement as akin to effectively placing small mirrors as it seems to me that the change in the structure in effect "reflects"as oppossed to the way I see refraction?
Still learning about it so excuse my greater than normal ...ignorance of the science involved.
alex