Dolphin-shaped cellular circular array super surface

Abstract

A new type of dolphin-shaped cellular circular array super surface producing a local composite polarized light field is provided. The super-surface is a circular array-shaped micro-nano metal structure, which consists of N (N>=3 and N is a positive integer) dolphin-shaped metal cellular structures which are rotatably arranged at the equal angle to form a circular array. Each dolphin-shaped metal cellular structure binds the incident light energy to the structural surface and eventually a local focusing strong field is produced at the tip of each dolphin-shaped cellular, so as to change the structural factor m (m> 1) to adjust the enhancement factor of the focusing field. Due to the structure of the dolphin-shaped metal cellular and the circular array structure formed by the equal-angle arrangement, and the incident linearly polarized light can be converted into a spiral phase beam. The ratio of the intensity of the z-direction component Ez of the transmitted field to the intensity of the total light field E decreases with increased in the propagation distance, and the Ez phase spiral effect is getting better with increased in the propagation distance. The dolphin-shaped cellular circular array super surface can be used as optical tweezers and optical angular momentum regulators, and has an important application value in broadband optical communication, optical imaging, nano-manipulation and other fields.

Description

technical field [0001] The invention belongs to the field of optics and optoelectronics technology, and relates to light field polarization modulation, nanometer manipulation, and surface plasmon excitation, in particular to a novel dolphin-shaped cellular circular array metasurface for generating local compound polarized light fields. Background technique [0002] When light passes through a structured material with subwavelength features, its propagation constant can depend on its polarization state, even if all its components are optically isotropic. At present, many kinds of subwavelength optical devices have been designed, which can control the polarization state of the light field, that is, the spin angular momentum. At the same time, the orbital angular momentum related to the space degree of freedom of the light field can also be adjusted. Orbital angular momentum has been identified as a useful degree of freedom to enhance the information-carrying capacity of photo...

AI Technical Summary

Problems solved by technology

However, in the existing research results, there is still insufficient research on how to control linearly polarized light into a vortex beam.

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