Metamaterial
Download as PPTX, PDF
3 likes2,650 views
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.
Metamaterial
- 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.
- 6. Definition of Metamaterial: Metamaterial coined in the late 1990s 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 (SRRs) 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 袖r and 竜r are negative negative 袖r and 竜r occur in nature, but not simultaneously silver, gold, and aluminum display negative 竜r at optical frequencies resonant ferromagnetic systems display negative 袖r at resonance rrn ワ 1 ))(( ))(( 2/2/ 2/1 緒 逸 逸 ワ j jj jj rr e ee ee
- 9. Negative Refraction n > 0 n > 0n < 0 Snells Law at the interface between a negative index material and a positive index material: ti nn 縁 sinsin 21 件 э it n n 縁 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 1990s 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