One-dimensional Photonic Crystal Angle Reflector

One-dimensionalphotonic crystal is a kind of periodic medium reflector that has very high reflectivity in the whole range of incident angle within a given wave band , which is the band gap of the one-dimensional photonic crystal. It breaks the limits of metal reflector and periodic medium reflector for realization of low loss and omnidirectional reflection. So it can be applied in many fields such as solar power collection, high precision filter, object searching and imaging.One-dimensional photonic crystal is composed of two or more kinds of medium which array periodically in one direction. This paper analyses the reason for the band gap existing in this periodic structure with both electromagnetism theory and thin film optics. The result of analysis points out that for a special periodic structure, there is a wave band in which the incident wave does not match with the optical states in the one-dimensional photonic crystal. So the incident wave in the wave band can not transmit in the one-dimensional photonic crystal and the wave band forms the band gap. Additionally, this paper analyses the optical properties of one-dimensional photonic crystal made of stratified anisotropic medium in theory.The band gap of one-dimensional photonic crystal is determined by the refraction index of medium. The larger the ratio of refraction index, the more obvious is the band gap. For our research emphasizes one-dimensional photonic crystal in visible light and near infrared light bands, we adopt two kinds of material ZnSe and NasAIFg which are both transparent in visible light band.Because the band gap is very narrow in visible light band, we have to pile up several stacks of low and high index film systems with the finalstructure of ( H1L1) 5 ( H2L2) 5 ( H3L3) 5H, which gets good effects in practice.During the practice, a lot of technical problems were met. We analyses the influences of different factors such as substrate temperature and evaporation rate based on many experiments. At last we got the best technical conditions for making one-dimensional photonic crystal.More over we analyze the influence of little disparity of both layer thickness and the refraction index with the method of tolerance analysis.Based on plenty of experiment data and analyzing results, we made several one-dimensional photonic crystals used in visible light and near infrared light which have band gaps from ten to a hundred nm.At last we introduced the progresses in making and property measuring of one-dimensional photonic crystals at home and abroad , and the new applications in practice as well.