INFLUENCE OF FLUCTUATIONS OF THE GEOMETRICAL PARAMETERS ON THE PHOTONIC BAND GAPS IN ONE-DIMENSIONAL PHOTONIC CRYSTALS

The in∞uence of random ∞uctuations in the layer thicknesses in high contrast, one-dimensional Photonic Crystals (PCs) on the transmission spectra and Photonic Band Gaps (PBGs) is investigated. The change in the PBGs depends on the magnitude of the ∞uctuations and increases with an increase in the order of the PBG. Introducing thickness non-uniformity into the PC of up to 0.004 times the value of lattice constant for difierent types of ∞uctuation distributions has a negligible efiect on either the position or the shape of the 1st and nearest PBGs. The approach suggested here allows the determination of the tolerances required in the geometrical parameters of PCs during fabrication. It also allows the optimisation of PC structures using high order PBGs.