The study of dielectric materials as photonic crystals based on the mechanism of photonic band gap

We report theoretical concepts and experimental verification for three-dimensional photonic crystal. The occurrence of photonic band gap, tunability and mechanism are given. We have theoretically formulated expressions for refractive index, central wavelength and temperature tuning of the photonic band gap. The lowest limit of refractive index contrast to yield a gap for closed packed face centered cubic lattice is also reported, which will pave the way to fabricate photonic crystals of materials of lower refractive index in comparison to that of silicon. The work reported also includes the recent advances on the fabrication of photonic crystals.