Omnidirectional reflection in one-dimensional ternary photonic crystals and photonic heterostructures

• We design the model of a one-dimensional ternary photonic heterostructure (TPH).
• We propose an approach to design optimal TPHs being able to create omnidirectional band gaps.
• The formula of the thicknesses of materials of the optimized TPHs is derived.
• The formula of the number of sub-ternary photonic crystals of the optimized TPHs is obtained.

Designing dielectric systems to create omnidirectional band gaps (OBGs) is an attractive topic in the field of photonic band gap (PBG) structures. In this Letter, we propose a new approach to create OBGs by ternary photonic heterostructures (TPHs) composed of three kinds of materials with different refractive indices and obtain the formulae of the structures of TPHs, i.e., those of the thicknesses of materials and the number of sub-ternary photonic crystals. It may provide a powerful technique for designing the structures being able to produce OBGs by use of usual materials, lowcost materials, and materials with low refractive indices, etc.