Near-ultraviolet to near-infrared band full-angle reflector based on photonic crystals

Abstract

The invention discloses a near-ultraviolet to near-infrared band full-angle reflector formed by overlaying two photonic crystals. The structure of the reflector is [A / B]m[C / D]n, lattice constant of the two photonic crystals is identical and is d which is equal to 160nm, dielectric constant of A and C is 1.96, the dielectric constant of B and D is 16, the thicknesses of A, B, C and D are d1 which is 0.76d, d2 which is 0.24d, d3 which is 0.5d and d4 which is 0.5d respectively, and m and n are cycle life of the two photonic crystals and are equal to 9. The near-ultraviolet to near-infrared band full-angle reflector can achieve full-angle reflection of near-ultraviolet to near-infrared bands, and the reflectivity is as high as more than 99%. When normal incidence of light is carried out, the forbidden band range is 375nm-1,189nm, and when incidence of the light is at an angle of 0 degree to 85 degrees, the forbidden band range can always be cover on the near-ultraviolet to near-infrared bands (375nm-893nm).

Description

technical field [0001] The invention relates to a photonic crystal reflector, in particular to a photonic crystal reflector capable of full-angle reflection in the near-ultraviolet to near-infrared band. Background technique [0002] As a new type of artificial optoelectronic functional material, photonic crystal has attracted much attention because of its good optical properties. A photonic crystal is an artificial crystal formed by a dielectric material that is periodically distributed in space. Its important feature is that it can form a photonic band gap. Light waves that fall within the band gap frequency range will not be able to propagate in the crystal. Using this feature can Use photonic crystals to make reflectors. Most of the materials used in photonic crystals are dielectric materials with low absorption coefficient, so the reflectivity is high, which can reach more than 99%. One-dimensional photonic crystals are simpler in structure and easier to prepare than ...

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Problems solved by technology

[0004] A. Mouldi et al. (Design of an omnidirectional mirror using one dimensional photonic crystal with graded geometric layers thicknesses, Optik. 2012, Vol:123, 125-131) mentioned that a wider band gap can be obtained by using the method of material thickness gradient, but the obtained forbidden The band width still does not cover the UV to NIR light band, and cannot be used for all-angle reflectors in the UV to NIR light band

[0005] Han Peide et al. (Omni-directional mirror for visible light based on one-dimensional photonic crystal, Chinese Optics Letters. 2011, Vol:9, 071603-071603) proposed to use four kinds of crystal phase superposition to obtain an all-angle reflector in the visible light band, but The band gap still cannot cover the near-ultraviolet to near-infrared light band, and this method requires a large number of crystal cycles and a complex structure

[0006] The 201210139917.0 patent application provides a photonic crystal-based full-visible light band full-angle reflector, which uses a one-dimensional photonic crystal with a composite structure of lithium fluoride and germanium [A / B] m [C / D] n , but its working range only covers the entire visible light band, and fails to cover the near-ultraviolet to near-infrared light bands in the full angle range

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