Transmission-type large-angle deflection double-layer uniform grating for 3D printing

Abstract

The invention relates to a double-layer uniform grating capable of realizing high-efficiency transmission-type large-angle deflection of 3D printing, and belongs to the technical field of novel artificial electromagnetic materials and terahertz science. The grating structurally comprises three layers, the lower layer is a uniform medium grating (1), the middle layer is a medium spacing layer (2), and the upper layer is a uniform medium grating (3) which has the same period with the lower layer but has different duty ratios with the lower layer. Each of the upper layer and the lower layer only comprises one grid structurein each period, and one side of the upper grid and one side of the lower grid are kept flush to form an asymmetric double-layer grating. By properly selecting the period of the grating and the size of internal grating bars, vertically incident sub-terahertz waves can be efficiently transmitted and deflected to a large-angle direction close to the surface of the grating. The grating is easy to design and process, can be quickly formed by using a 3D printing technology, is low in cost, and provides a new scheme for the development of extreme sub-terahertz functional devices.

Description

technical field [0001] The invention relates to a 3D printed transmissive large-angle deflection double-layer uniform grating, which belongs to the fields of new artificial electromagnetic materials and terahertz science and technology. Background technique [0002] The control of beam direction is one of the basic functions of various optical systems. Large-angle beam deflection is the physical basis for applications such as large numerical aperture lenses and improved spectral resolution. The deflection direction of beams in traditional components is determined by Snell's law, and metasurfaces composed of subwavelength structural units are used as a A designable boundary impedance provides a new idea for arbitrary control of the beam direction, and then develops the generalized Snell's law based on metasurfaces. How to design the shape and size of the subwavelength unit to meet the required impedance is the key to the realization of related functions. [0003] Studies ha...

AI Technical Summary

Problems solved by technology

However, in the sub-terahertz frequency band, which is highly concerned by applications such as wireless communication and security inspection imaging, the microfabrication process of silicon-based gratings cannot achieve the required thickness, and high-efficiency transmissive large-angle deflection gratings have not been reported.

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