A Periodic Dielectric Grating and Terahertz Wave Focusing Lens

Abstract

The invention relates to a periodic dielectric grating and a terahertz wave focusing lens. The periodic dielectric grating comprises a dielectric substrate with a plane and a plurality of dielectric units arranged on the plane; the dielectric units are periodically arrayed on the plane in the transverse and longitudinal directions of the plane; any of the dielectric units has the same width in thetransverse and longitudinal directions; all the dielectric units have the same height in the direction perpendicular to the plane. The periodic dielectric grating has high transmission transmissivity, can conduct phase regulation on incident terahertz waves and is insensitive to polarization.

Description

technical field [0001] The invention relates to the technical field of terahertz metamaterials, in particular to a periodic dielectric grating and a terahertz wave focusing lens. Background technique [0002] Terahertz is a section of the electromagnetic spectrum between microwave and infrared radiation, and it is also a precious frequency resource that needs to be fully developed and utilized. Its frequency range is 0.3THz-3THz, and its wavelength range is 0.1mm-1mm. With the rapid development of current terahertz science and technology, the important value of terahertz waves has received more and more attention, which has brought a large number of applications in the fields of terahertz communication, imaging, material detection and medical imaging. [0003] The transmission and reception of focused terahertz waves is the key to detecting matter in terahertz sensing and imaging systems. The traditional method of collimating and focusing terahertz waves is to use quasi-opti...

AI Technical Summary

Problems solved by technology

The above terahertz lens using the phase gradient metasurface of the periodic metal structure realizes the phase control of the transmitted terahertz wave by adjusting the size of the metal unit structure, but its transmission coefficient is generally small, because the metal is similar to an ideal conductor in the terahertz band, Its reflection of terahertz waves is relatively large, so the energy of focused terahertz waves is also small

At the same time, the phase change range of the metal structure to the transmitted terahertz wave is also small. Although there is also a method to increase the transmission phase of the terahertz wave by using a multilayer metal structure, this will increase the complexity of the structure.

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