Properties and characteristics Negative-index metamaterial

a split-ring resonator array arranged produce negative index of refraction, constructed of copper split-ring resonators , wires mounted on interlocking sheets of fiberglass circuit board.

the total array consists of 3 20×20 unit cells overall dimensions of 10×100×100 millimeters. height of 10 millimeters measures little more 6 subdivision marks on ruler, marked in inches.

credit: nasa glenn research center.

electrodynamics of media negative-index of refraction first studied russian theorist victor veselago in 1967. proposed left-handed or negative-index materials theorized exhibit optical properties opposite of glass, air, , other transparent media. such materials predicted exhibit counterintuitive properties bending or refracting light in unusual , unexpected ways. however, first practical metamaterial not constructed until 33 years later , produce veselago s concepts.

currently, negative-index metamaterials being developed manipulate electromagnetic radiation in new ways. example, optical , electromagnetic properties of natural materials altered through chemistry. metamaterials, optical , electromagnetic properties can engineered changing geometry of unit cells. unit cells materials ordered in geometric arrangements dimensions fractions of wavelength of radiated electromagnetic wave. each artificial unit responds radiation source. collective result material s response electromagnetic wave broader normal.

subsequently, transmission altered adjusting shape, size, , configurations of unit cells. results in control on material parameters known permittivity , magnetic permeability. these 2 parameters (or quantities) determine propagation of electromagnetic waves in matter. therefore, controlling values of permittivity , permeability means refractive index can negative or 0 conventionally positive. depends on intended application or desired result. so, optical properties can expanded beyond capabilities of lenses, mirrors, , other conventional materials. additionally, 1 of effects studied negative index of refraction.

reverse propagation

when negative index of refraction occurs, propagation of electromagnetic wave reversed. resolution below diffraction limit becomes possible. known subwavelength imaging. transmitting beam of light via electromagnetically flat surface capability. in contrast, conventional materials curved, , cannot achieve resolution below diffraction limit. also, reversing electromagnetic waves in material, in conjunction other ordinary materials (including air) result in minimizing losses occur.

the reverse of electromagnetic wave, characterized antiparallel phase velocity indicator of negative index of refraction.

furthermore, negative-index materials customized composites. in other words, materials combined desired result in mind. combinations of materials can designed achieve optical properties not seen in nature. properties of composite material stem lattice structure constructed components smaller impinging electromagnetic wavelength separated distances smaller impinging electromagnetic wavelength. likewise, fabricating such metamaterials researchers trying overcome fundamental limits tied wavelength of light. unusual , counter intuitive properties have practical , commercial use manipulating electromagnetic microwaves in wireless , communication systems. lastly, research continues in other domains of electromagnetic spectrum, including visible light.