Design of omnidirectional reflectors based on a cascaded one-dimensional photonic crystal structure

The omnidirectional transmission properties of photonic heterostructures composed of cascaded one-dimensional photonic crystals (1DPCs) with the same materials and different thickness ratios of the alternate high- and low-refractive index layers were studied theoretically. A criterion for designing omnidirectional reflectors with a maximum bandgap width is presented for heterostructures with an arbitrary number of cascaded 1DPCs. Omnidirectional reflectors based on two and three cascaded 1DPCs are designed according to the criterion.