Metamaterials are artificial materials engineered to have properties not found in nature. They are composed of periodic microscopic structures that interact with electromagnetic waves in ways that allow properties like a negative index of refraction. This presentation outlines metamaterials, how they achieve unusual properties, their timeline of development, applications like cloaking and terahertz devices, and remaining challenges in fabricating optical metamaterials.

1. MetamaterialsAnd Its
clocking
Presented
By
P. KIRAN (09F01A0488)
Under the esteemed guidance
of
B. V. V. Ravindra Babu ,M.Tech.
ELECTRONICS AND COMMUNICATION ENGINEERING

2. Presentation Outline
 Introduction to Metamaterials
 Definition of Metamaterial
 How Metamaterials work
 Time Line
 What are Negative Index Metamaterials (NIMs)?
Negative Index Metamaterial Features
Negative Refraction
 Applications
 Conclusion

3. Introduction to Metamaterials
Meta: Greek prefix meaning “Beyond”

4. Introduction to Metamaterials:
Why are they called Metamaterials?
 Existing materials only exhibit a small subset of electromagnetic
properties theoretically available
 Metamaterials can have their electromagnetic properties altered
to something beyond what can be found in nature.
 Can achieve negative index of refraction, zero index of refraction,
magnetism at optical frequencies, etc.

5. Introduction to Metamaterials :

6. Definition of Metamaterial:
“Metamaterial” coined in the late 1990’s
 Any material composed of periodic, macroscopic
structures so as to achieve a desired electromagnetic
response can be referred to as a Metamaterial
very broad definition:
 Others prefer to restrict the term Metamaterial to
materials with electromagnetic properties not found in
nature
 Still some ambiguity as the exact definition

7. Veselago first studies the effect a negative permittivity and permeability has on
wave propagation 1968
Pendry proposes wire structures to realize a negative
permittivity1996
Pendry proposes Split Ring Resonators (SRR’s) to realize a
negative permeability
Pendry proposes another wire structures to realize a
negative permittivity
1999
2000
T
I
M
E
L
I
N
E

8. How Metamaterials Work
• Example: How to achieve negative index of refraction
• negative refraction can be achieved when both µr and εr are negative
• negative µr and εr occur in nature, but not simultaneously
• silver, gold, and aluminum display negative εr at optical frequencies
• resonant ferromagnetic systems display negative µr at resonance
rrn 
 
1
))((
))((
2/2/
2/1










j
jj
jj
rr
e
ee
ee

9. Negative Refraction
n > 0 n > 0n < 0
Snell’s Law at the interface between a negative index material and a positive
index material:
ti nn  sinsin 21 






 
it
n
n
 sinsin
2
11
Refracted beam will be opposite to the normal
as shown in the animation above.

10. Metamaterials beyond negative index
Low index metamaterials
Indefinite media
High index
metamaterials
Shrinkage of devices
Cloaking
Single-negative media
Parallel beam
formation

11. Applications
• Terahertz requirement
• Photonic applicati
• Cloaking devices
• Radar applications
• Mobile applications

12. conclusion
Introduction of metamaterials in 1990’s opened new
possibilities in electromagnetics.
 Successful implementation of metamaterial technology
in the microwave spectrum.
 Inherent difficulties exist in fabricating optical
metamaterials
 Most work to date related to modeling proposed designs

13. References:
• Smith, D. R., et al., Phys. Rev. Lett. (2000) 84, 4184
• Pendry, J. B., et al., IEEE Trans. Microw. Theory
Tech. (1999) 47, 2075
• Veselago, V. G., Sov. Phys. Usp. (1968) 10, 509
• www.google.com
• www.nanotechnology.bilkent.edu.tr/research%20areas
/documents/mm-waveleft-handed.htm
• http://en.wikipedia.org/wiki/Metamaterial

14. Copyright
2003
Applied
Logic
Engineering

15. Copyright
2003
Applied
Logic
Engineering