Construction of one-dimensional photonic crystals based on the incident angle domain

An effective method used to extend the band gap of hybrid one-dimensional photonic crystals is proposed. This method does not require one-dimensional photonic crystals used in the construction of hybrid photonic crystals to have omnidirectional photonic band gaps. This property gives the designers more freedom to select materials used in the design. Another advantage of this method is the ability to obtain very large omnidirectional photonic band gaps of hybrid structures without using too many one-dimensional photonic crystals. Some structures are constructed by this method to prove it. By using TiO2 and SiO2, the structure composed of four one-dimensional photonic crystals based on this method has been calculated and fabricated. The theoretical relative bandwidth of an omnidirectional photonic band gap is 41.33%, and the experimental result is up to 37%, which is very large in the visible region. By comparison, the theoretical relative bandwidth of the conventional method based on the frequency domain is only 14.26%.