New 'superlens' will revolutionize astronomy, medicine, biology.

These are lenses that operate on a principle of "negative refractive
index". They are able to break the diffraction limit that was believed
to limit the resolution achievable in an optical system based on its
aperture and the wavelength observed:

Angular resolution.
http://en.wikipedia.org/wiki/Angular...on#Explanation

Already they are being used to create sub-diffraction limit images in
microscopy:

Metamaterials found to work for visible light.
Ames Laboratory researchers have found the first metamaterial known to
work for visible light, announcing the discovery in the Jan. 5 issue
of Science.
14:54, January 04, 2007
http://www.physorg.com/news87144852.html

'Superlens' has its reach extended.
Tom Simonite
17:23 01 February 2007
NewScientist.com news service
http://www.newscientisttech.com/arti...-extended.html

New superlens opens door to nanoscale optical imaging, high-density
optoelectronics.
22.04.2005
A group of scientists at the University of California, Berkeley, is
giving new relevance to the term "sharper image" by creating a
superlens that can overcome a limitation in physics that has
historically constrained the resolution of optical images.
http://www.innovations-report.de/htm...cht-43432.html

Sub-Diffraction-Limited Optical Imaging with a Silver Superlens.
Nicholas Fang, Hyesog Lee, Cheng Sun, Xiang Zhang*
Science, 22 April 2005: Vol. 308. no. 5721, pp. 534 - 537.
Recent theory has predicted a superlens that is capable of producing
sub-diffraction-limited images. This superlens would allow the
recovery of evanescent waves in an image via the excitation of surface
plasmons. Using silver as a natural optical superlens, we demonstrated
sub-diffraction-limited imaging with 60-nanometer half-pitch
resolution, or one-sixth of the illumination wavelength. By proper
design of the working wavelength and the thickness of silver that
allows access to a broad spectrum of subwavelength features, we also
showed that arbitrary nanostructures can be imaged with good fidelity.
The optical superlens promises exciting avenues to nanoscale optical
imaging and ultrasmall optoelectronic devices.
http://www.sciencemag.org/cgi/content/full/308/5721/534

However, the superlenses work by detecting near field light waves
which are quite close to the object being observed, within a light
wavelength.
A key question is can their use be extended to work for objects that
are far away, which would be required for astronomy.
There is some research on possible ways this might work:

Telescope resolution using negative refractive index materials.
Jack L. May and Tony Jennetti
Northrop Grumman Mission Systems (USA).
Proceedings of SPIE -- Volume 5166
UV/Optical/IR Space Telescopes: Innovative Technologies and Concepts,
Howard A. MacEwen, Editor, January 2004, pp. 220-227
"Concepts are presented for using negative refractive index (NRI)
materials to design parabolic reflector telescopes and antennas with
resolutions significantly better than the diffractions limit. The main
question we are attempting to answer is can negative refractive
material be used to improve performance of parabolic systems even when
the signal or light source is far away and no evanescent fields are
present when they arrive at the parabolic reflector. The main approach
is to take advantage of any knowledge that we have to recreate the
evanescent fields. Fields are then adapted to improve a performance
measure such a sharper focus or antenna rejection of interference. A
negative refraction index lens is placed between the conventional
reflector and focal plane to shape the point spread function. To
produce telescope resolutions that are better than the diffraction
limit, evanescent fields created by the reflection off of the
parabolic surface are amplified and modified to generate fields that
sharpen the focus. A second approach use available knowledge of an
emitting aperture to synthesize a field at a distance that matches as
closely as possible the field of the emitting aperture. The yet
unproven conclusion is that techniques can be developed that will
improve antenna and telescopes resolution that is better than the
diffraction limit."
http://link.aip.org/link/?PSISDG/5166/220/1 [Abstract only]

If this succeeds then telescope apertures will only need to be a
fraction of their current size to achieve the same resolution. This
will be fundamentally important for space based telescopes.

The revolution in medicine and biology the superlens will allow has
to do with the confirmation of a hypothesized, but controversial, form
of life, the nanobacteria. I believe the nanobacteria will be proven
to exist and will be found to be pathogens for disease in humans.
There are for example some diseases that give the appearance of
infectious disease but for which no infectious agent has been
identified.
One such case is for example kidney stones. Some papers have been
written suggesting nanobacteria as their cause. Very small nanoscale
objects were seen in connection with the kidney stones but these
objects could not be confirmed as being alive.
The problem is these nanoscale objects can be seen for example with
electron microscopes, but this kills any putative life forms being
examined. The new superlens will allow these nanoscale objects to be
observed in optical wavelengths, at smaller sizes than the wavelengths
used, and as I say alive. You could for example do spectroscopy on
them to confirm they contain the organic molecules for life, and
perhaps as well observe their life cycle in real time.
The confirmation of a new form of life previously believed impossible
will certainly be revolutionary. The team that confirms them for
example I believe will be deserving of a Nobel prize. It's just a
matter of time, a short time.


Bob Clark

In article om,
Robert Clark wrote:
"The yet unproven conclusion is that techniques can be developed that will
improve antenna and telescopes resolution that is better than the
diffraction limit."
If this succeeds then telescope apertures will only need to be a
fraction of their current size to achieve the same resolution.

Careful here. "Better than" doesn't necessarily mean "much better than".
If memory serves, the far-field diffraction limit is a fairly direct
consequence of the Uncertainty Principle, which means that you may be able
to cheat on it a bit with a sharp lawyer :-), but it's *not* going to just
go away. Mumbling about "recreating" the evanescent fields ignores the
question of whether enough information is present to do so.

Also note carefully that some of the techniques they are discussing assume
that the shape or some other characteristic of the emitter is *known*.
It's easy to get "resolution" better than the diffraction limit if you
know what you're looking for; for example, a small object can be detected
against a contrasty background even if its size is well below the
diffraction limit. (The classic example is that under good conditions,
astronauts looking down from orbit can see things like roads, which are
demonstrably much narrower than the diffraction limit of their eyes.)

Even the claim that negative-refractive-index microscopy may revolutionize
biology has more hype than substance. There are *already* several methods
for doing *near-field* optical imaging to resolutions much better than the
diffraction limit, and they have proven useful but not revolutionary.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

"Sam Wormley" wrote in message
news:SaJFh.22900$PD2.10812@attbi_s22...
Robert Clark wrote:


If this succeeds then telescope apertures will only need to be a
fraction of their current size to achieve the same resolution. This
will be fundamentally important for space based telescopes.


Bull****--show us the calculations!


they are trying to fool mother nature.

In article SaJFh.22900$PD2.10812@attbi_s22,
Sam Wormley wrote:

Robert Clark wrote:


If this succeeds then telescope apertures will only need to be a
fraction of their current size to achieve the same resolution. This
will be fundamentally important for space based telescopes.


Bull****--show us the calculations!

Yup. Diffraction limiting has to be taken into account somewhere.

Plus, telescopes are "big" for other reasons than resolution -- light
gathering is something that only big apertures can do.

Isaac

On Mar 1, 7:52 pm, (Henry Spencer) wrote:
In article om,

Robert Clark wrote:
"The yet unproven conclusion is that techniques can be developed that will
improve antenna and telescopes resolution that is better than the
diffraction limit."
If this succeeds then telescope apertures will only need to be a
fraction of their current size to achieve the same resolution.

Careful here. "Better than" doesn't necessarily mean "much better than".
If memory serves, the far-field diffraction limit is a fairly direct
consequence of the Uncertainty Principle, which means that you may be able
to cheat on it a bit with a sharp lawyer :-), but it's *not* going to just
go away. Mumbling about "recreating" the evanescent fields ignores the
question of whether enough information is present to do so.

Also note carefully that some of the techniques they are discussing assume
that the shape or some other characteristic of the emitter is *known*.
It's easy to get "resolution" better than the diffraction limit if you
know what you're looking for; for example, a small object can be detected
against a contrasty background even if its size is well below the
diffraction limit. (The classic example is that under good conditions,
astronauts looking down from orbit can see things like roads, which are
demonstrably much narrower than the diffraction limit of their eyes.)

Even the claim that negative-refractive-index microscopy may revolutionize
biology has more hype than substance. There are *already* several methods
for doing *near-field* optical imaging to resolutions much better than the
diffraction limit, and they have proven useful but not revolutionary.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

The Zhang group was able to resolve objects at 1/6th the wavelength,
60 nm as opposed to a 365 nm wavelength. If used with uv light at 200
nm, the lowest wavelength commonly used by biologists in light
microscopy, they could image down to 30 nm. This very likely could
resolve the nanobacteria in real time in "live" conditions.
There are some methods coming into use now that use the near field
light waves to image below the diffraction limit but these are
expensive systems not commonly available to biologists in general:

Near-field Scanning Optical Microscopy.
http://physics.nist.gov/Divisions/Di...nsom/nsom.html

The advantage of these new "near field" lenses is that they will be
much cheaper so every biologists could have one in their tool kit.
Then the existence and prevalence of the nanobacteria will be as
easily determined as microbial cells are now.
It might be though you won't have to create specifically negative
refractive index materials. Here's a another report that easily
creates the same effect:

Phys. Rev. Lett. 94, 057401
(issue of 11 February 2005)
A Microscope from Flatland
"Biologists dream of a point-and-shoot camera that can reveal details
smaller than a wavelength of light in living cells. Now, in the 11
February issue of PRL, researchers show that "two-dimensional" light--
short-wavelength light waves that live on a surface--can improve
resolution without the expensive equipment and special preparations
needed for electron microscopes and other technologies. The team
imaged nanoscale holes as a demonstration, but they believe the
technique could ultimately take instant shots and even movies of the
biological nanoworld."
http://focus.aps.org/story/v15/st3

Note this is still using the near field waves to create this effect.

That negative refractive index materials can be used for the lens far
from the object as in astronomy is indeed not proven but apparently
the Zhang team believes this is possible:

New superlens opens door to nanoscale optical imaging and high-density
optoelectronic devices.
By Sarah Yang, Media Relations | 21 April 2005
http://www.berkeley.edu/news/media/r...uperlens.shtml

The near field effects are purely classical EM effects so are not
dependent on QM for their derivation. It may be that QM will put some
ultimate limitation on how far the subwavelength resolution can go.
Still 1/6th wavelength resolution is still an important advance.


Bob Clark