Such media have special microstructures, designed to provide overall (dynamic) material properties that natural materials can never hope to attain and lead to the seemingly rather strange notions of negative refraction
, wave redirection, the holy grail of cloaking.
Unique properties of HM can lead to a wide variety of applications; among these are negative refraction
[10, 11], subwavelength imaging [12-17], spontaneous and thermal emission engineering [18-21], and broadband light trapping [22, 23].
Pendry, "Negative refraction
makes a perfect lens," Physical Review Letters, vol.
There exist abnormal negative refraction
effect , inverse Cerenkov radiation, reverse Doppler effect , and negative radiation pressure  in NIMs because the electromagnetic wave group velocity and phase velocity of these materials are oriented in the opposite direction; based on these principles, optical film contained NIMs has broad application prospects in microwave communication, large capacity storage medium, and superresolution imaging.
Revolutionary devices that can get around the diffraction limit include so-called superlenses made from metamaterials with negative refraction
indices that bend light in an opposite sense to conventional materials.
Vaselago had introduced the concept of negative refractive index materials (left handed materials (LHM)) in 1968  which exhibits a negative refractive index due to the simultaneous negative permeability and permittivity and these materials have electromagnetic properties such as negative refraction
, reversed Doppler shift and reversed Cerenkov radiation.
It was stated through theoretical and experimental results that anisotropic chiral media can have a negative refraction
index like isotropic media with both negative permittivity and permeability.
In 2009, Leonhardt proposed that perfect imaging can be achieved without a negative refraction
Forester, "Negative refraction
and focusing of circularly polarized waves in optically active media," Physical Review Letters, vol.
Veselago in detail studied the interesting property of negative refraction
in left handed materials .
The results can be utilized for realization of a helical array metamaterial which has demonstrated the negative refraction
This edition has been updated with new examples, exercises, and sections on optical control of spin, quantum dots, diamond NV centers, carbon nanostructures, negative refraction
, and plasmonics.