Semiconductor for Photonic Structures

SEMICONDUCTOR FOR PHOTONIC STRUCTURES

PHOTONIC CRYSTALS

• Photonic crystals are spatially a periodic structures of dielectric materials with different refractive indices. It is a medium in which refractive index varies periodically on the order of wavelength of light.

• Photonic crystals can guide the motion of photons using the photonic band gap. This is analogous to the electronic band gap semiconductor crystals to guide electrons.

• Photonic crystals are made from periodic patterns of materials with different permittivities. When a photon travels through an interface between two materials of different permittivity, the photon may be reflected.

• The reflection depends the arrangement of atoms in a material's crystal lattice.

• The photons of certain wavelengths pass through the material, while photons of a specific range of wavelengths will be reflected. This represents the photonic band gap that is a range of photon wavelengths (frequencies) are forbidden.

• They cannot pass through the photonic crystal.

• Opal is an example of a naturally occurring photonic crystal. A typical spacing between material layers in a photonic crystal is in the order wavelength of light (about 500 nm).

• A photonic crystals can organize photons based on their energy, confine the photons them to small cavities, or guide the photon.

Types of Photonic Crystals

They are '3' type of photonic crystals. They are

(i) 1D photonic crystal 

(ii) 2D photonic crystal.

(iii) 3D photonic crystal.