A Theoretical study on Negative Refractive Index Metamaterials (Review)
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Transcript of A Theoretical study on Negative Refractive Index Metamaterials (Review)
A Theoretical study on Negative Refractive Index Metamaterials (Review)
Madhurrya P. Talukdar Tezpur University
Contents
• Introduction• Negative refraction• Electromagnetic Wave propagation• How to make NIM• Conclusion
Introduction
Invisibility
Camouflage Stealth technology
Vacuum property(most effective)
Possible types of materials:
•μ>0, Є>0, being most known materials, natural or otherwise.
•μ>0, Є<0, being materials not well investigated.
•μ<0, Є>0, also being materials not well investigated
•μ<0, Є<0, where these materials do not exist naturally(Metamaterials)
Metamaterials
Man-made materials
First introduced theoretically by Victor Veselago in 1967
Consists of Artificially structured units (meta-atoms)
Meta atoms composed of two or more conventional materials
Negative refraction:
empty glass regular water, n = 1.3
“negative” water, n = -1.3
Group velocity vg is in the opposite direction to the wave (or phase) velocity, vp
The structural array of metamaterials must be smaller than the EM wavelength used.
To achieve negative refraction MM’s must interact with the magnetic component of light.
* ‘Probing the Magnetic Field of Light at Optical Frequencies’ Brussi et.al VOL 326 SCIENCE
Electromagnetic wave propagation and cloaking
Theory
Transformation optics is a simple approach to design MM’s (Pendry et.al)
Light enters n > 0 material deflection
Light enters n < 0 material focusing (“Veselago Lens”)
What happens to light in NIM?
Fermat’s principle states light rays take the shortest optical paths in dielectric media
When n is spatially varying shortest optical paths are usually curved.
Fig: bending of light around a cloaked object (Leonhart 2006)
Cloaking
W. Cai et al., “Optical cloaking with meta-material,” Nat. Photonics 1, 224 (2007).
G. Abajo et al., “Tunneling mechanism of light transmission through metallic films,” Phys. Rev. Lett. 95, 067403 (2005).
T. Ebbesen et al., Nature 391, 667 (1998).
G. Gay et al., Phys. Rev. Lett. 96, 213901 (2006).
W. Barnes et al., Phys. Rev. Lett. 92, 107401 (2004).
A. Alu & N. Engheta, Phys. Rev. E 72, 016623 (2005).
In microwave range: use “perfectly” conducting components to simulate < 0 and < 0, Smith et.al., (2000)
How to make NIM?
Metal poles: = 1 – p2/2 < 0
Split-ring resonators, Pendry’99: “geometric” resonance at M
2/1
log(D/r)
2
D
cp
0 122
2
M
MF
Split Ring Resonators
At frequency> resonant frequency the real part of μ of the SRR becomes negative.
Combining the negative permeability with negative dielectric constant of another material to produce negative refractive index metamaterials.
Challenges: (a) moving to optical frequencies (infrared, visible, UV) (b) simplifying the structure ( < 0 and < 0 from same element)
Optical meta-materials have been shown to have remarkable applications:
Can be used to engineer exotic meta-media: Negative Index Materials plasmonic approach to making a sub-l NIMNIMs and negative e materials can be used to overcome diffraction limit and construct a super-lens
A super-lens enables ultra-deep sub-surface imaging
Very new field lots of work to do (theory and experiments)
Conclusion
References
1.Veselago, V.G. Sov.Phys. Usp. 10, 509-514(1968).2.Pendry, J.B. Phys. Rev. Lett. 85, 3966-3969(2000)3.Pendry, J.B., Schurig, D. & Smith, D.R. Science 312, 1780-1782(2006).4. D. L. Mills and E. Burstein, Rep. Prog. Phys. 37, 817 (1974).5. R. E. Camley and D. L. Mills, Phys. Rev. B 26, 12806.A. Hartstein, E. Burstein, A. A. Maradudin, R. Brewer, and R. F.Wallis, J. Phys. C 6, 1266 (1973).7.D. R. Smith, D. C. Vier, Willie Padilla, Syrus C. Nemat-Nasser, and S. Schultz, Appl. Phys. Lett. 75, 1425 (1999).8.C.R. Simovski, Physical Optics. 107, 766-793.9. D. R. Smith, D. C. Vier, Willie Padilla, Syrus C. Nemat-Nasser, and S. Schultz, Phys. Rev. Lett. 84, 4184-4187(2000)10.Pendry, J. B., A. J. Holden, W. J. Stewart, and I. Youngs, Physical Review Letters, Vol. 76, 4773-4776, (1996).11.Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, IEEE Trans. on Microwave Theory and Techniques,Vol. 47, 2075-2084, (1999).12.C. Sabah, H.G. Roskos, Progress In Electromagnetics Research Symposium Proceedings, Moscow, Russia, August 18-21, 2009.13.A. Grbic and G.V. Eleftheriades, J. App. Phys. 98, 43106 (2005)14.D.R. Smith, J. Opt. soc. Am. B 21, 1032 (2004)15.D.R. Smith, J.B. Pendry, J. Opt. Soc. Am. B 23 391 (2006).16.P.K.L. Drude, Theory of Optics(Longmans, London, 1902; ONTI, Moscow, 1935)17.I.E. Tamm, Z. Phys. 76, 849 (1932).18.C.R. Simovski, Metamaterials 1, 62 (2007)19.C.R. Simovski, Metamaterials 2, 342 (2008)20.C.R. Simovski , Phys. Rev. B 62, 13718 (2000)
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