History of metamaterials

The history of metamaterials begins with artificial dielectrics in microwave engineering as it developed just after World War II. Yet, there are seminal explorations of artificial materials for manipulating electromagnetic waves at the end of the 19th century. Hence, the history of metamaterials is essentially a history of developing certain types of manufactured materials, which interact at radio frequency, microwave, and later optical frequencies. As the science of materials has advanced, photonic materials have been developed which use the photon of light as the fundamental carrier of information. This has led to photonic crystals, and at the beginning of the new millennium, the proof of principle for functioning metamaterials with a negative index of refraction in the microwave- (at 10.5 Gigahertz) and optical range. This was followed by the first proof of principle for metamaterial cloaking (shielding an object from view), also in the microwave range, about six years later. However, a cloak that can conceal objects across the entire electromagnetic spectrum is still decades away. Many physics and engineering problems need to be solved. Nevertheless, negative refractive materials have led to the development of metamaterial antennas and metamaterial microwave lenses for miniature wireless system antennas which are more efficient than their conventional counterparts. Also, metamaterial antennas are now commercially available. Meanwhile, subwavelength focusing with the superlens is also a part of present-day metamaterials research. Classical waves transfer energy without transporting matter through the medium (material). For example, waves in a pond do not carry the water molecules from place to place; rather the wave's energy travels through the water, leaving the water molecules in place. Additionally, charged particles, such as electrons and protons create electromagnetic fields when they move, and these fields transport the type of energy known as electromagnetic radiation, or light.