Photonic Crystal Technology
3. Photonic Crystal Essentials
The key to understanding photonic crystals is the dependancy of the interaction between
light waves and the structure on the period of the structure. The most widely know example
of a multilayer optical film is the Bragg reflector.
The Bragg reflector employs the phenomenon of total reflection, which occurs as a result
of the intensity of the reflected light increasing at each layer as shown in the figure below.
Research on the electron transmitted as (an electromagnetic wave) in periodic atomic structures
of the atom is established as band theory. A similiar model is applicable to the interaction
of a photonic crystal and light.
Despite the periodicity of photonic crystals being on the order of 100nm, they are referred to as crystals
by analogy to molecular structures with a periodicty on the order of angstroms (1 Angstrom=0.1nm).
The wavelength range over which light is transmitted through the crystal is called
the "Photonic Band" and the range over which light is not transmitted the "Photonic Bandgap".
