Terahertz radiation source based on non-relativistic electron beam excitation of dielectric waveguide

Abstract

The invention discloses a non-relativistic electron beam induced dielectric waveguide-based terahertz radiation source. The non-relativistic electron beam induced dielectric waveguide-based terahertz radiation source includes a pulse laser light source used for emitting a laser pulse string, a frequency adjusting device used for adjusting the repetition frequency of the laser pulse string, an electron gun and a dielectric waveguide; the cathode of the electron gun is used for absorbing the laser pulse string and transmitting an electron beam cluster string; a size-adjustable electric field formed between the cathode and anode of the electron gun is used for accelerating the emitting of the electron beam cluster string into the dielectric waveguide; the dielectric waveguide is excited by the electron beam cluster string to form terahertz radiation; and the repetition frequency of the laser pulse string and the radiation frequency of the dielectric waveguide form resonance. With the non-relativistic electron beam induced dielectric waveguide-based terahertz radiation source adopted, energy conversion efficiency between the electrons and radiations of the terahertz radiation source can be effectively improved, radiation power can be improved, radiation frequency is adjustable. The cost of the terahertz radiation source can be reduced.

Description

technical field [0001] The invention relates to the technical fields of electron accelerators and vacuum electronics, and more specifically relates to a terahertz radiation source based on a non-relativistic electron beam exciting a dielectric waveguide. Background technique [0002] Due to the broad application prospects of terahertz waves in many fields such as life science, material science, communication technology and national security, it has attracted widespread attention of scientists at home and abroad. Terahertz waves refer to electromagnetic waves with a frequency between 0.1-30THz. THz sources are the basis for the development of terahertz science. THz radiation sources based on non-relativistic electron beam excitation mainly include: the return wave oscillator (BWO) of the traditional vacuum electronics method ) and the Smith-Purcell radiation (SMITH-PURCELL radiation) in the THz band excited by electron beam clusters. Among them, the first type of THz radiati...

AI Technical Summary

Problems solved by technology

Among them, the first THz radiation source, namely BWO, is generally used in low-frequency THz radiation sources, but it requires extremely high starting current density. For example, the current density required to generate electromagnetic radiation with a frequency above 1 THz is usually hundreds of A / cm 2 , far exceeding the emission capabilities of existing cathodes

The second THz radiation source is the Smith-Purcell radiation in the THz band excited by electron beam clusters. It does not require high current density electron beams as the excitation source, but its energy conversion rate is low, and the radiation power is only about 1mW; In addition, the interval between the micropulses in the electron beam train it uses cannot be adjusted, so its radiation frequency cannot be adjusted

Using relativistic electron clusters with adjustable intervals to excite the dielectric waveguide to generate THz radiation, although it can generate high-power radiation, but because the electron speed is close to the speed of light, its radiation can only be at a few specific frequencies and cannot be continuously adjusted; In addition, because the high-energy electron beam needs to be generated by a large accelerator, its cost is high and the peripheral support equipment is huge.

In short, due to the use of gratings as the radiation medium in the prior art, the radiation conversion rate is low and the radiation power is low. Since the relativistic electron beam with the speed of light is used as the excitation source for exciting the radiation medium in the prior art, the radiation frequency cannot be determined. tone

Images