Metamaterial structure for modulating terahertz wave

Abstract

The invention relates to a metamaterial structure for modulating a terahertz wave, comprising a central medium layer, an upper surface grid layer and a lower surface grid layer. The central medium layer is made of a polyethylene materials transparent to the terahertz wave and has a thickness smaller than the one-tenth wavelength of an incident terahertz wave; the upper surface grid layer adopts metal material and comprises a series of parallel grids periodically distributed on the upper surface of the central medium layer; each grid and gaps at both sides of the grid form a period, and the thickness of each grid is smaller than the width thereof; the lower surface grid layer adopts a metal material and comprises a series of parallel grids periodically distributed on the lower surface of the central medium layer; each grid and gaps at both sides of the grid form a period,, and the thickness of each grid is smaller than the width thereof; and the grids of the upper surface grid layer and the lower surface grid layer are symmetrically distributed in a mirror mode. The invention has the advantage that the modulation range of the terahertz wave is widened by a modulator because the transmission of the terahertz wave is constantly enhanced by a surface plasma wave.

Description

technical field [0001] The invention belongs to the technical field of metamaterials, in particular to a metamaterial structure used for terahertz wave modulation. Background technique [0002] Terahertz waves are usually defined as coherent electromagnetic radiation with frequencies in the range of 0.1 to 10 THz. The English corresponding to terahertz is teraherta, abbreviated as THz, 1THz=1012Hz (hertz), the oscillation period is 1ps (picosecond), the wavelength is 30μm (micron), and the energy of photons is 4.1meV (millielectron volts). The terahertz waves that are currently studied are usually in the range of 0.3~3THz, and their bands are located between microwaves and infrared rays. They belong to the category of far infrared rays and submillimeter waves, and are sometimes called T-rays. Their notable features are: 1. Transient: The typical pulse width of terahertz waves is on the order of picoseconds, which can not only facilitate time-resolved research on various mat...

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Problems solved by technology

However, the resonance absorption of the buckle itself is very obvious, which still cannot meet the modulation of THz broadband

Due to the limitation of the material structure characteristics of the metamaterial used in the modulator, the above method results in a small modulation range and high requirements for the use environment, which is not conducive to the popularization and application of terahertz wave technology.

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