Cerenkov terahertz radiation source based on cylinder graphene surface plasma wave

Abstract

The invention discloses a Cerenkov terahertz radiation source based on cylinder graphene surface plasma wave. The Cerenkov terahertz radiation source completely covers a graphene ribbon of a cylindrical dielectric rod, the cylindrical graphene dielectric rod structure has the 2pai periodicity in a circumference direction, so that the surface plasma wave chromatic dispersion can penetrate through the medium light speed line, the surface plasma wave can be matched with the transmission wave vector in the dielectric, so that the surface plasma wave motivated by the annular electron can be directly converted into the coherent Cerenkov terahertz radiation in the dielectric rod without using the wave vector compensation; the radiation power density is enhanced to two to three order of magnitudeby the surface plasma wave. The Cerenkov terahertz radiation source can be used for developing the radiation source which works at room temperature, has coherence and high power and is capable of covering the whole terahertz waveband.

Description

technical field [0001] The invention belongs to the technical field of radiation source engineering, and relates to a Cerenkov terahertz radiation source based on cylindrical graphene surface plasma waves, specifically a coherent terahertz radiation source that can be used in systems such as terahertz imaging, security inspection and communication. source of terahertz radiation. Background technique [0002] Terahertz waves lie between microwaves and infrared rays on the electromagnetic spectrum. Terahertz waves have many unique properties. First, their photon energy is low, which is lower than the bond energy of various chemical bonds, and can be used for non-destructive and safe detection of the human body and various organisms. Secondly, the wavelength of terahertz is longer than that of visible light, so it can see through smoke, etc., and has good penetration to many substances (ceramic, fat, carbon plate, cloth, plastic). Furthermore, the terahertz spectrum has a wid...

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Problems solved by technology

However, the grating structure also faces the problems of low efficiency and difficult implementation

First of all, the graphene-loaded dielectric grating structure is a periodic system. The graphene SPPs and the field in the space are the superposition of infinitely many spatial harmonics, but the SPPs only carry a small amount of energy carried by the negative first-order spatial harmonic, which is converted into Radiation field, so energy conversion is less efficient

Secondly, the surface finish of the grating whose period is only on the order of microns is very poor, and the graphene covering the surface of the grating is extremely fragile, and there are great difficulties in technical implementation

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