Transcript Negative Refractive Index And Metamaterial :Current

Negative Refractive Index And
Metamaterial :Current Scientific
Progress and Applications
-Shiv Ashish Kumar
Outline
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Introduction of Metamaterial and NIM.
Concepts to reality
Structure for NIM
Application
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Metamaterial
• Meta means Beyond in greek
• Meta material literally means beyond
conventional material.
• They are typically man made material .
• Having a properties not found in nature.
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Negative refractive index
In naturally exiting substances permittivity and permiability are
positve (except the cases of noble metals like gold silver etc where
permitivitty is negative for certain range of frequency).
Now lets consider that :
neff 
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0
 0
( )(  )
Shiv Ashish Kumar
    n
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Negative refractive index
• So we see that a negative refractive index can
be obtained in principle if both permittivity
and permeability are negative simultaneously.
• This makes the left hand material.
• Why we want negative refractive index ??
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Negative Refractive index
Snell`s Law
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Negative refractive index

•Snell`s law is still valid
 2
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Concept
•The first theoritical study was performed by V.G VESELAGO and
it took nearly 30 years for experimental verification.
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Concepts to reality
D.R Smith has shown for the first time simultaneously
negative Permeability and Permittivity
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Concepts to reality
Sir J.B Pendry has given the concept of
perfect lens using negative refractive index.
This is one of the great break though work in
the world of meta material.
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Concepts to reality
Till 2007, shortest Wavelength 725nm at which
 0
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Different structures used for designing
NIM.
• The famous SRR(split ring resonator
suggested by Sir Pendry)
• First Realized by D.R Smith group in 2001.
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Structure for NIM
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Structure for NIM
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Negative Refractive index in optics
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Application
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Applications
Cloaking
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Applications
Watching your back !!
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Problems
High Dissipative losses is a big problem and limits the application .
We are still far from having a practical device.
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The famous people in the world of
meta material
• V.G Veselago
• Sir John Brian Pendry , imperial college
,London.
• Professor David R. Smith ,Duke University
• Vladimir M. Shalaev , Perdue university.
• Xiang Zhang , University of California
,Berkeley.
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