Multi-stage terahertz modulator based on flexible graphene field effect transistor structure

Abstract

The invention belongs to the technical field of terahertz wave application, and provides a multi-stage terahertz modulator based on a flexible graphene field effect transistor structure. The multi-stage terahertz modulator is used for overcoming the defects that an existing graphene transistor terahertz modulator is small in modulation depth and only the switch-on state and the switch-off state can be achieved. The terahertz modulator is of an up-and-down-symmetry structure, and comprises a substrate, graphene films, ionic gum, source electrodes, drain electrodes and gate electrodes, wherein the graphene films, the ionic gum, the source electrodes, the drain electrodes and the gate electrodes are symmetrically arranged on the upper surface and the lower surface of the substrate, the graphene films are arranged on the surfaces of the substrate, the source electrodes, the ionic gum and the drain electrodes are arranged on the surfaces of the graphene films, and the gate electrodes are arranged on the surfaces of the ionic gum. According to the terahertz modulator, two flexible graphene field effect transistors are arranged on the two sides of the same flexible substrate, the modulation depth of the modulator can be increased by 37% or above, and meanwhile four-stage modulation of the amplitude of terahertz waves can be achieved through cascade controlling.

Description

technical field [0001] The invention belongs to the technical field of terahertz wave applications, and relates to a terahertz modulation device, in particular to a multi-level terahertz modulator based on a flexible graphene field-effect transistor structure. Background technique [0002] Terahertz wave (terahertz wave) refers to electromagnetic waves with a frequency of 0.1-10THz and a wavelength of 30μm-3mm. Its wave band is located between microwave and infrared waves. It has unique electromagnetic characteristics and occupies an important position in the electromagnetic spectrum. Terahertz waves have very important applications in the fields of biomedical diagnosis, wireless communication, radar imaging, electronic countermeasures, homeland security and environmental monitoring, and are of great significance to the national economy and national defense construction. Terahertz modulators, a key core component of terahertz communication systems and radar imaging systems, ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a multi-level terahertz modulator based on a flexible graphene field effect transistor structure to overcome the defects of low modulation depth and only two switching states of the existing graphene transistor terahertz modulator The core of the present invention is to adopt a double-layer flexible graphene field-effect transistor structure, and two flexible graphene field-effect transistors are respectively arranged on both sides of the same flexible substrate, which can greatly improve the modulation depth of the device to more than 37%; at the same time, through Reasonable control of two flexible graphene field-effect transistors can obtain multiple modulation states and realize multi-level modulation of terahertz wave amplitude, so that terahertz modulators can achieve higher data rate transmission in a single channel, and can also be widely used Used in systems such as terahertz imaging and detection; in addition, the modulator of the present invention also has the advantages of flexibility, broadband, low insertion loss, etc.

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