Transparency with plasmonic (aka invisibility)

[5614]

In a recent paper brought out called "Achieving transparency with plasmonic coatings" The idea of using plasmonic coatings to make an object appear transparent was suggested. The proposal involves using plasmons to cancel out the visible light or other radiation coming from an object.

 

This idea only works on a small (microscopic) scale.

 

The full paper can be seen here (for free):

http://arxiv.org/ftp/cond-mat/papers/0502/0502336.pdf

 

And more about plasmons can be found at:

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

http://home.hccnet.nl/ja.marquart/BasicSPR/BasicSpr01.htm

 

I found this link where it was published by Nature but a subscription (which I don't have) is needed so I cannot verify the link works, but it looks hopefull from what I can see:

http://www.nature.com/news/2005/050228/full/050228-1.html

[JPQuiceno]

Thanks dude! Really cool stuff..........

[reyam200]

if you could make a cloth(or just a flexable materal) coated with those plasmons, you could make a invisability cloak like on harry potter. that would be awsome

[Norman Albers]

According to Science News this is indeed happening, and is a channeling of light issue. How would you make a Navy destroyer seem to disappear? I think I could if I could blow a cloud of dense gas in front and behind. What do you think?

[Klaynos]

I'm actually working on metamaterials research which have interesting resonant effect, which are what alot of people are talking about using for this, atm, very interesting work...

 

Wish I could tell you more but can't

[Norman Albers]

Right now it's tuned to one frequency by the construction. I forgot the other part of the plot: negative index of refraction! Yes that would complete my lensing cloud, wouldn't it? Commend me to DARPA. In my paper on gravitation permittivity does all manner of things. On the way to my electron model are three others with different assumptions where it goes negative. I rejected those for electrons but now it's in my face for gravitation and I welcome it. . . . . . . . . Let's see, optics guess: a giant torus of optically more dense gas, blown like a smoke-ring, and/or a center (axial) region of optically thinner gas. The point I guess is to create index gradient outward.

[gcol]

According to Science News this is indeed happening, and is a channeling of light issue. How would you make a Navy destroyer seem to disappear? I think I could if I could blow a cloud of dense gas in front and behind. What do you think?

 

Nice one, Albie, but unless it works like one-way glass, I would not volunteer for lookout duty:

 

Captain to lookout: "There is an iceberg warning, keep your eyes peeled".

Lookout to captain "What icebergs? cant see a damn thing through this plasmonic fog, can't see sh**t".

 

Or even "captain to phalanx, inbound exocet bearing green 045, lock on target". "You must be joking, cant even zap a seagull through this murk".

 

Perhaps "Hey, Abdullah, there's a cloud of that plasmonic stuff on the horizon"

"Must be a damn Yank, lob a heatseaking missile into it".

 

How about "Ooops, crunch smash gurgle gurgle, did not see you there, assumed our radar was on the blink".

 

Loads of laughs.

[Norman Albers]

[bIG TEETH] Good'un, mate! Very funny stuff. Supposedly something weird happened with the Navy in the "Philadelphia incident" in the '40's.

[Severian]

if you could make a cloth(or just a flexable materal) coated with those plasmons, you could make a invisability cloak like on harry potter. that would be awsome

 

That wouldn't be very useful since only the cloak would be invisible - not what was inside.

 

(It would be nice for fashion in cold climates though.)

[Norman Albers]

The idea is to channel the light from behind the object to project out the front, not to make a cloth that is transparent. Not that I'm arguing with your fashion preferences, Severian.

[Severian]

Well. if you take the light in one side of the cloth and channel it out the other side, then it is still going to be reflected by the person's body and come right back at you.

 

To do what you are suggesting one would need for the cloth to know exactly which bit of the cloak is on the other side of the person's body, channel the light to that part of the cloak and fire it out in exactly the same direction...

[Norman Albers]

No, cloaks are not about to happen but spheres and lenses are! Negative index metamaterials can theoretically channel light around a region. In a different game, conductive nanocoatings block emission/scattering, the Goldfinger effect one better. In this case you would not see what's behind, just a lack of light I guess? Gcol's point of not seeing out is well taken. We shall have 100-meter periscopes, I don't know.

[JesuBungle]

Sounds like I better get to work on a metamaterial detector and sell it to whatever army wants it:D

[Klaynos]

Sounds like I better get to work on a metamaterial detector and sell it to whatever army wants it:D

 

Very very very simple to do... You've just got to use a frequency outside that which the metameterial is 'tuned' to...

[Norman Albers]

I need to get straight about relative indices. What is negative here, precisely? Is index of refraction less than one but positive? This would imply negative polarizability, I guess. What is the speed of light here? It is predicted that these things give opposite Doppler shift!

[Norman Albers]

Wikipedia has enough on negative index to mess up my mind. I have only recently myself approached the plus/minus possibility on the square root of permittivity times permeability. These guys are not in Kansas and the index is negative. I am going to my room.

[Norman Albers]

I am currently visualizing magnetic permeability of the vacuum as being proportional to electric permittivity in low energy regimes. If we can engineer the necessary phases for negative results, could we figure how to create a slightly lower value, compared with the vacuum? This would be handy.

[Rocket Man]

i don't know the term for the effect, but a particular compound can be "doped" with a particular wavelength light such that it can no longer interact with any other photons. the experiment was set up such that an IR laser shone onto a crystal rendering it invisible...

[Norman Albers]

The metamaterial rings put around a metal ring (partly) cancelled both reflections and forward shadow.