Metamaterial terahertz oscillator and control method therefor

Abstract

The invention discloses a metamaterial terahertz oscillator and a control method therefor. The metamaterial structure comprises a periodical sub-wavelength metallic slit array; the metamaterial terahertz oscillator comprises the metamaterial structure, electron guns, drifting cavities, energy extraction structures, electron collectors and a magnetic focusing system; the overall device has the advantages of relatively small structural dimension and compactness; in addition, the energy extraction is more convenient and rapid; the metamaterial structure is filled with dielectric, so that the equivalent refractive index of the metamaterial structure can be further increased; the equivalent refractive index of any value can be obtained within any terahertz frequency according to the parameter design of the metamaterial structure, so that great convenience is brought to the low-voltage operation of the device; furthermore, the upper surface and the lower surface of the metamaterial structure emit electron beams concurrently, so that the interaction efficiency and the output power can be further improved; and meanwhile, the metamaterial terahertz oscillator provided by the invention also has the characteristic of low loss.

Description

technical field [0001] The invention relates to the technical field of terahertz (THz) electromagnetic wave sources, in particular to a metamaterial terahertz oscillator and a control method thereof. Background technique [0002] Metamaterials, that is, materials with artificial structures, also known as left-hand materials, are a type of special materials that do not exist in nature. Due to its special structure, the response characteristics of metamaterials to electromagnetic waves are often different from those of conventional materials, such as metals and media. The dielectric constant ε and magnetic permeability μ of common materials in nature are both real numbers greater than zero (ε>0, μ>0), so the electromagnetic waves they support can only be in the state of propagation, that is, double positive coal quality. However, one of the permittivity and permeability of metamaterials must be a negative number, that is, there is a single negative metamaterial (the per...

AI Technical Summary

Problems solved by technology

At present, the devices with the largest output power in the terahertz band are vacuum electronic devices. Gyrotrons and free electron lasers can reach kilowatt-level outputs at terahertz, but gyrotrons often rely on external magnetic fields, and free electron lasers rely on peripheral devices such as Accelerators, etc., so these two high-power devices are difficult to develop into compact terahertz sources

Other linear devices such as return wave oscillators, klystrons, traveling wave tubes, etc. are often compact, but when the operating frequency increases to terahertz, the size of the device is often small due to its scaling effect. Therefore, the thermal capacity is limited, and the output power is difficult to reach the watt level

And other terahertz radiation sources based on free electron beams, such as Smith-Purcell radiation (Smith-Purcell radiation) (Y.Shin, J.So, K.Jang, J.Won, A.Srivastava and G.Park, Appl .Phys.Lett.,90,031502,2007), Cherenkov radiation (J.So,J.Won,M.A.Sattorov,S.Bak,K.Jang,G.Park,D.S.Kim and F.J. Garcia-Vidal, Appl.Phys.Lett., 97, 151107, 2010) and Diffraction radiation (S.Liu, M.Hu, Y.Zhang, Y.Li and R.Zhong, Phys.Rev.B ,80,036602,2009) can work in the terahertz band, but it requires high electron beam energy and low radiation efficiency

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