Multi-structure combined artificial electromagnetic surface

Abstract

The invention discloses a multi-structure combined artificial electromagnetic surface that produces a local composite polarized light field with high locality and high longitudinal field component ratio characteristics. The artificial electromagnetic surface has three combinations of a metal dolphin-shaped cell circular array metal cylinder, a dolphin-shaped cell circular array graphene layer, anda metal dolphin-shaped cell circular array metal cylindrical graphene layer. The substrate is a commonly used dielectric material in the visible light band, and a linearly polarized Gaussian beam inthe visible light band is used as an incident source. The radius of the circular array is R1, the radius of the metal cylinder is R2, the thickness of the metal material layer is D1, and the thicknessof the graphene layer is D2. Metal dolphin-shaped cell circular array metal cylinder composite structure can excite high locality and high longitudinal field component ratio of vector vortex light field and metal cylinder. The larger the radius, the stronger the locality of the light field and the larger the proportion of the longitudinal field component. The metal dolphin-shaped cell circular array graphene layer combination structure can generate a high locality vector vortex light field. The vector vortex light field excited by the metal dolphin-shaped cell circular array metal cylindricalgraphene layer combined structure takes into account the high locality and high longitudinal field component ratio. The electromagnetic surface has important application value in the fields of quantum communication, molecular screening and nano manipulation.

Description

technical field [0001] The invention belongs to the field of micro-nano optics, and is designed for light field regulation, nano-manipulation, and surface plasmon excitation, especially a multi-structure combined artificial electromagnetic field that produces a local composite polarized light field that takes into account both localization and high longitudinal field component ratio characteristics. surface. Background technique [0002] Vortex beams carrying orbital angular momentum are attracting increasing attention. The properties of vortex beams are exploited to extend their applications, such as optical communication, optical tweezers and quantum computing. The vortex beams were created a decade ago by spiral phase plates, spatial light modulators and computer-generated holograms. At present, in most cases, vortex beams are generated by miniaturized and integrated sub-wavelength scale artificial optical components. [0003] Nonetheless, vector beam generation with s...

AI Technical Summary

Problems solved by technology

First, the components that convert a linearly polarized beam into a vortex beam are very difficult to fabricate

The integrated micro-nano helical cone structure of the optical device can realize the excitation of the vector vortex beam when the linearly polarized light is incident, by using only the components used to directly convert the linearly polarized laser beam into the vortex beam without the polarization converter, however. It is difficult to fabricate the vertices of the nanohelical cones whose mesoscale is only a few nanometers in practice, which will greatly affect the resolution and localization of the transmitted field

Second, easily fabricated subwavelength optics can only convert circularly polarized light into vortex beams in most cases

Nowadays, many researchers use two-dimensional artificial subsurfaces with subwavelength scales to excite vortex beams. However, on the basis of the Pancharatnam-Berry phase principle, in most cases only circularly polarized light can be obtained by using artificial electromagnetic surface to be converted into a vortex beam, so there is little mention of producing a vortex beam by illumination with linearly polarized light

In previous studies, metal dolphin-shaped cell circular array metasurfaces were used to convert linearly polarized light into vector vortex beams, thus taking into account the above two problems, but the locality of the transmitted field and the longitudinal field component accounted for The ratio is not very ideal, which will affect the precise manipulation and manipulation sensitivity of nanoparticles, thus greatly affecting the application of two-dimensional artificial electromagnetic surfaces in actual production and life.

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