Metamaterials

Metamaterials

The new metamaterial world has liberated theorists to dream and challenged experimentalists to make them happen.
keister Pendry
Metamaterials argon artificially structured materials that have properties that cannot be effectuate in nature. The literal definition comes from the Greek meta, meaning beyond. From the technological and engineering viewpoint, the interest in metamaterials is based on the possibility of designing devices and systems with new properties or functionalities, able to control surface up new fields of application or to cleanse existing ones.
There argon several types of metamaterials, each with contrastive applications. The first type of metamaterials that will be discussed are photonic metamaterials, which are designed to interact with optical frequencies. These structures are made from at least two different materials, usually involving both metals and dielectrics. They are normally periodic, with the period being small compared to the optical wavelength. Therefore, the excess optical properties do not arise from photonic bandgaps, but instead from an interaction which is more similar to that of atoms or ion in a normal solid medium.

Figure 1. Band structure in insulators or semiconductors
A bandgap is an energy range in a solid where no electron states can exist.



In other(a) words, the bandgap is the difference between the bottom of the conduction band and the exculpate of the valence band (Figure 1) in insulators and semiconductors. This is equal to the energy demand to free an outer shell electron from its orbit roughly the nucleus.
The next type of metamaterial, which is the most studied one, is an electromagnetic metamaterial. prior to understanding electromagnetic metamaterials, a brief explanation of the electromagnetic spectrum must be presented.

Figure 2: The electromagnetic spectrum
The electromagnetic spectrum is the range of frequencies existing due to electromagnetic radiation, ranging from short wavelengths such(prenominal) as gamma rays to...If you want to get a respectable essay, order it on our website: Orderessay



If you want to get a full essay, wisit our page: write my essay .