Artificial super-surface electromagnetic wave amplitude modulator based on graphene

Abstract

The invention provides an artificial super-surface electromagnetic wave amplitude modulator based on graphene, and mainly solves the problems of small modulation scope and narrow modulation bandwidth of a conventional electromagnetic wave amplitude modulator. The artificial super-surface electromagnetic wave amplitude modulator comprises a DC power supply and a frequency selection surface, three layers of dielectric substrates and a reflecting plate laminated from top to bottom sequentially, wherein a dielectric layer with relative dielectric constant less than three is arranged between the second dielectric layer and a reflecting plate to expand wave absorption bandwidth, the frequency selection surface is formed by m*n cross period units, a rectangular-ring metal paster embedded in a graphene film is arranged in the center of each cross period unit, metallic branches are connected to the upper and lower sides of the rectangular-ring metal paster, and the horizontal metallic fine leads connect the single cross units in an entire row into one body. The structure is simple, and metal pasters embedded in the graphene films are used to widen the modulation bandwidth and increase the reflection wave modulation amplitude. The reflecting plate with high conductivity is used to reduce the transmission of electromagnetic waves by a wave absorption device. The artificial super-surface electromagnetic wave amplitude modulator is applicable to active electromagnetic hiding and electro-optical switch equipment.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic stealth, and mainly relates to an amplitude modulator, in particular to a graphene-based artificial metasurface electromagnetic wave amplitude modulator, which can be used for active electromagnetic stealth and electro-optic switch equipment. Background technique [0002] Graphene is a honeycomb two-dimensional film material composed of a single layer of hexagonal primitive cells of carbon atoms. It has a unique two-dimensional structure and a zero-gap electronic energy band. It has extremely high electron and hole mobility, excellent mechanical Electrical, optical properties and good conductivity tunable characteristics, suitable for optical devices and transparent electromagnetic devices, such as polarizers, filters, reflectors, modulators and surface plasmon polariton (SPP) transmitters, etc. , is a new material with adjustable performance and great potential. [0003] The artificial e...

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Problems solved by technology

[0004] At present, many artificial electromagnetic metasurface structures can realize the modulation of electromagnetic wave amplitude, but considering factors such as modulation bandwidth and modulation amplitude, their modulation results are not completely satisfactory, and there is still a lot of room for improvement in their modulation amplitude and bandwidth.

For example, in 2012, Sensale-Rodriguez et al. published "Extraordinary Control of Terahertz Beam Reflectance in Graphene Electro-absorption Modulators" in the NANO LETTERS journal (2012,12(9):4518-4522.), in which the electrically tuned single-layer graphite was used The method of Graphene realizes the design of reflective terahertz wave amplitude modulator. The surface structure of the modulator is only composed of a graphene film. This structure overcomes the problem of small amplitude modulation range, but the relative operating bandwidth of the modulator is 10%, the modulation bandwidth is relatively narrow

In 2014, David S. Jessop et al. published "Low-bias terahertz amplitude modulator based on split-ringresonators and graphene" in American Chemical Society journal (2014,8(3):2548-2554.), in which split-ring resonators and graphene were used The composite structure of graphene superposition can dynamically modulate the reflected wave intensity by adjusting the bias voltage of the metamaterial, but the modulation depth of the modulator is only 18%, the amplitude modulation range is small, and the modulation bandwidth is lower than 20%, and the relative working bandwidth is very narrow , which will limit the scope of application of this modulator, and the practicability is not good enough

On the one hand, the modulation bandwidth of this type of modulator designed in the prior art is narrow, and it is difficult to meet the modulation of a wide frequency range; on the other hand, its modulation method is not convenient and flexible enough, and the amplitude modulation range is very small, which greatly affects the modulation effect

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