Femtosecond Plasma Terahertz Radiation Power Postgraduate In Technology And Applications

The generation of terahertz by femtosecond plasma is a current research hotspot.This method can provide high-power and ultra-wideband terahertz radiation,which is widely used in many fields.However,the terahertz wave generated by this method has serious absorption and loss in the transmission process,so it is necessary to further improve its terahertz radiation efficiency and conduct application research.This paper first uses a photocurrent model to numerically simulate the gas terahertz radiation under different pressure conditions;secondly,a femtosecond plasma terahertz radiation system is constructed,and its mixed terahertz radiation enhancement effect is tested using a mixed gas;finally,Radiation-enhanced terahertz sources have been used in terahertz spectroscopy for four energetic materials.Research indicates:(1)A numerical simulation was performed using a photocurrent model.The simulation results show that within the range of 50-700 torr pressure,the generation of terahertz is proportional to the pressure of the gas medium,so the terahertz radiation power can be increased by increasing the pressure of the gas medium.(2)By constructing a femtosecond plasma terahertz radiation system,an experimental study of argon and air in equal proportions has been conducted.The results show that in a mixed gas,a two-color laser generates plasma filaments and radiates terahertz waves outward,producing terahertz waves.The intensity of the terahertz radiation is about 2.5 times that in the atmospheric environment,and the terahertz power generated is about 5 times that in the atmospheric environment.It is proved that the terahertz radiation intensity and power generated in the mixed gas medium environment will be significantly enhanced.(3)The application research of radiation-enhanced terahertz sources has been carried out.The experimental results show that the terahertz absorption peak positions of the four energetic material samples detected will not change with the sample concentration,and the degree of absorption will change with the sample concentration.Prove that terahertz radiation enhancement systems can detect explosives.This paper proposes the use of mixed gas as a filament medium to generate terahertz waves,which provides a new method for terahertz generation technology.At the same time,the application research of terahertz radiation enhanced by this method for explosives detection is terahertz for explosives.Testing provides new ideas.