Radiation source capable of dynamically tuning radiation parameters and radiation parameter tuning method

Abstract

The invention discloses a radiation source capable of dynamically tuning radiation parameters and a radiation parameter tuning method. The radiation source comprises a dielectric substrate, a waveguide and an electrode array are arranged on the dielectric substrate, a plurality of graphene strips are arranged on the waveguide, a gap is formed between every two adjacent graphene strips, and the electrode array is used for adjusting the bias voltage of each graphene strip so as to dynamically tune the radiation parameter of the radiation source under the condition that the radiation frequency is not changed. The metasurface structure formed by the graphene strip is adopted, a waveguide mode is radiated into the space, and on the basis that the grating structure is formed, under the condition that the radiation frequency is not changed, radiation parameters such as the line width and the grating period are actively and dynamically tuned by changing the bias voltage on the graphene strip; in addition, the line width can be tuned in a wider range and can be narrowed to 1 * 10 <-8 > times of the radiation frequency to the minimum, and the radiation power density is remarkably enhanced.

Description

technical field [0001] The invention relates to the field of coherent radiation sources, in particular to a radiation source capable of dynamically tuning radiation parameters and a method for dynamically tuning radiation parameters. Background technique [0002] Smith-Purcell radiation (S-P radiation) is an electromagnetic wave generated by free electron injection through a diffraction grating, and plays an important role in free electron light sources and particle accelerators. [0003] Existing terahertz radiation sources using S-P radiation generally have a structure composed of a substrate and a periodic dielectric grating, and generally electron beams moving in parallel excite surface plasmon polaritons (SPPs) to generate terahertz radiation. Patent CN110571626A discloses a terahertz radiation source for a planar multi-electron injection excitation graphene sub-wavelength integrated grating. By setting a grating structure and laying a graphene layer on the grating stru...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a radiation source and a radiation parameter tuning method that can dynamically tune the radiation parameters, so as to solve the problem that the radiation parameters such as the line width, amplitude, and radiation direction of the radiation source cannot be dynamically tuned under the condition of constant frequency in the prior art. To achieve the purpose of dynamically tuning the radiation parameters such as line width, grating period, radiation direction, radiation harmonic order, photon yield, radiation power density and so on by changing the bias voltage of graphene under the condition of constant frequency

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