Making negative refraction with positive index material

In summary: I recognize the fact that people have attempted to do this, but I am looking for actual proof that this is possible.In summary, the conversation discusses the possibility of using positive index materials to mimic the effects of metamaterials, specifically negative refraction. The participants also mention existing examples of positive index materials, such as layered semiconductors and ferromagnets, and the challenges of using them in applications. The conversation ends with a suggestion to explore this idea further and a request for concrete evidence of its feasibility.
  • #1
St. Aegis
38
0
I was thinking about and I think it might be possible, but before I do anything stupid, anything have an opinion about this?
 
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  • #2
Are you referring to metamaterials?
 
  • #3
positive index material is any material that is not meta-material
like glass, meaning index n>1
 
  • #4
St. Aegis said:
positive index material is any material that is not meta-material
like glass, meaning index n>1

Er.. technically, the rods and split rings that make up the metamaterial ARE positive index material! It is how the geometry of the various components of the metamaterial that causes it to have the left-handed property.

There are others, such as layered semiconductors:

http://physicsworld.com/cws/article/news/31554;jsessionid=412475B70D3407BA28ADCE13778A3672

The only "natural" material that I know of is a ferromagnet that was reported recently:

A. Pimenov et al. Phys. Rev. Lett. 98, 197401 (2007);
http://physicsworld.com/cws/article/news/30020 (free registration required).

But I'm not sure if this is the "positive index material" that you're looking for, which, as I've described above, is rather strange, since the metamaterial and layered semiconductors are made up of positive index material.

Zz.
 
  • #5
It is called "anomalous dispersion" the permittivity is positive and can be greater than one, but it decreases with increasing frequency. It usually occurs near a resonance of the material, and is difficult to use because the absorption is very high there.
 
  • #6
They are calling these 'metamaterials'. Originally negative index of refraction was demonstrated in the microwave region. The push is on to develop materials toward the visible range of the spectrum. As clem indicates, as developed, they are frequency selective. Wikipedia has an article on metamaterials.
 
  • #7
well yes i know that all matter, except metamaterials exhibit this, but I was thinking, for like things like glass, it is definitely impossible right?
 
  • #8
St. Aegis said:
well yes i know that all matter, except metamaterials exhibit this, but I was thinking, for like things like glass, it is definitely impossible right?

The fact that you already know that glass has a positive index of refraction makes the question puzzling. I'm guessing you don't intend to use glass to construct either layered or a metamaterial.

Zz.
 
  • #9
I swear, when I posted #6 only the initial post and Clem's were visible... What gives?
 
  • #10
The op made 2 identical threads, which is a no-no on PF. Since both already had responses, I merged both of them into one.

Zz.
 
  • #11
couldnt you orient some materials such that negative refraction occurs?
 
  • #12
ZapperZ said:
The op made 2 identical threads, which is a no-no on PF. Since both already had responses, I merged both of them into one.

Zz.

Thanks, Zapper
 
  • #13
St. Aegis said:
couldnt you orient some materials such that negative refraction occurs?

Assuming that you're still stuck with "glass" or other positive index material, then isn't this what is done with the metamaterial in the first place? I mean, look at the orientation of the rods and split rings, for example, with respect to the orientation of the E and B fields of the EM radiation.

This is getting puzzling all the time, because it appears that you are aware of the development in this field, but then you continue to ask things that, to me, are rather obvious. Can you tell me what it is that you're looking for that is not satisfied by the metamaterial? I can tell you right off the bat that so far, the characteristics that you're asking (material with positive index, having a certain orientation) fit with the metamaterial. So why isn't that sufficient? How about being a bit more verbose in your question and what exactly you're trying to get at, rather than just a one-line response? What I've typed here in this post alone is more than what you've typed in all of your posts in this thread combined, and frankly, I'm getting tired of putting all this one-sided effort.

Zz.
 
  • #14
no no no,
imagine, that you have slabs of material right? Now light strikes one material, but let's say that this material is tilted in one direction, such that when light strikes this medium, what occurs is that light will bend (let us assume the second material's index is much higher than the original material). Right? This means that light can be directed in the same direction of negative refraction when light is shone through. I find this quite awkward I do not mean just electromagnets and everything, I mean the actual meta-materials. I find it awkward that this effect can be mimicked. Now say that you can use this in application; then we won't have to create meta-materials but rather know how to arrange positive refraction material to bend light in that manner. Do you see where I am going with this?
 
  • #15
bump?
 
  • #16
St. Aegis said:
no no no,
imagine, that you have slabs of material right? Now light strikes one material, but let's say that this material is tilted in one direction, such that when light strikes this medium, what occurs is that light will bend (let us assume the second material's index is much higher than the original material). Right? This means that light can be directed in the same direction of negative refraction when light is shone through. I find this quite awkward I do not mean just electromagnets and everything, I mean the actual meta-materials. I find it awkward that this effect can be mimicked. Now say that you can use this in application; then we won't have to create meta-materials but rather know how to arrange positive refraction material to bend light in that manner. Do you see where I am going with this?

Nope. This makes no sense.

Besides, do you think physicists and engineers are that dumb to not even think or attempted such a thing, especially when they could come up these matematerial?

Zz.
 
  • #17
well besides considering that physicists should explore everything around them, I say why not and be that dumb. Hell, people spend government money playing around with computer programs, I don't see why not.
Besides, what I am looking for is actual proof.
 

FAQ: Making negative refraction with positive index material

What is negative refraction?

Negative refraction is an optical phenomenon where light is bent in the opposite direction of what is expected, based on the traditional laws of refraction. This means that the light waves will bend away from the normal line, instead of towards it.

How is negative refraction achieved with positive index materials?

Negative refraction can be achieved with positive index materials by using a specialized structure known as a metamaterial. These materials are engineered to have an effective negative refractive index, allowing for the manipulation of light waves to create negative refraction.

What are the potential applications of negative refraction with positive index materials?

The potential applications of negative refraction with positive index materials are vast and include advancements in imaging, telecommunications, and optical computing. It can also be used to create superlenses with the ability to resolve objects smaller than the wavelength of light.

Are there any challenges or limitations to creating negative refraction with positive index materials?

Yes, there are some challenges and limitations to creating negative refraction with positive index materials. One major challenge is the fabrication of metamaterials with the precise engineering needed to achieve negative refractive index. Another limitation is the narrow range of wavelengths that can be manipulated using current techniques.

How does negative refraction with positive index materials differ from traditional refraction?

Negative refraction with positive index materials differs from traditional refraction in two main ways. First, the direction of the refracted light waves is opposite of what is expected in traditional refraction. Second, negative refraction can occur at angles greater than the critical angle, which is not possible with traditional refraction.

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