Preparation method of all-dielectricthree-dimensional broadband gradient refractive index lens

Abstract

The invention discloses a preparation method of a full-medium all-dielectric three-dimensional broadband gradient refractive index lens. The preparation method comprises the steps of achieving a part with lower dielectric constant by utilizing a metamaterial-scale three-dimensional photonic crystal with a gradually-changed space structure parameter, achieving a part with a larger dielectric constant by adopting a mixed liquid medium in different mixing ratios, assembling a space structure parameter gradient metamaterial-scale three-dimensional photonic crystal structure the metamaterial-scale three-dimensional photonic crystal with a gradually-changed space structure parameter and a multi-layer frame filled with the mixed liquid medium according to dielectric constant distribution, and then obtaining the prepared full-medium all-dielectric three-dimensional broadband gradient refractive index lens. The lens can achieve a very broad refractive index variation range, can achieve impedance matching with an air background, and has the advantages of low loss, broadband and the like due to the non-resonance characteristic of the lens and the low loss characteristic of a material.

Description

technical field [0001] The invention belongs to the field of metamaterials and gradient refractive index lenses, and relates to a preparation method of an all-medium three-dimensional broadband gradient refractive index lens. Background technique [0002] Gradient-index materials play an important role in gradient-index devices used to control electromagnetic wave propagation. The traditional preparation methods of graded-refractive-index materials, such as ion exchange, sol-gel, chemical vapor deposition, organic polymerization, crystal growth, and neutron irradiation, all have different limitations, such as too high production Cost and complex manufacturing process, limited range of refractive index variation, large electromagnetic wave loss of the medium used, etc. [0003] Gradient index lenses, such as Maxwell fisheye lenses, Lunbo lenses, Eaton lenses, etc., are typical gradient index devices. They have important application value in imaging, radar, antenna and other...

AI Technical Summary

Problems solved by technology

However, the development brought about by transformation optics and metamaterials is still constrained by the realization of three-dimensional gradient index materials. How to realize its broadband performance and large refractive index range is also difficult: the use of resonant metal metamaterials will lead to greater losses. and a single bandwidth; non-resonant metal metamaterials have a wide operating frequency band, but it is still difficult to expand to three dimensions; holes with sub-wavelength dimensions on layered dielectric plates can achieve three-dimensional gradient refractive index changes, but due to Due to the limitations of its manufacturing materials, it is difficult to achieve a large range of refractive index changes, and its inherent two-dimensional cylindrical hole structure damages three-dimensional isotropy; based on all-medium mixed particle materials such as titanate, three-dimensional refraction can also be achieved However, the control of the refractive index is inconvenient, and it is still subject to a small range of refractive index variation, which does not match the air impedance

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