The Effect Of Electromagnetic Conduction By Characteristic Of Femtosecond Laser Plasma Filament

In 1995, scientists first discovered that a femtosecond laser in air can form a long distance transmission plasma filament. The plasma filament was caused by balance between the self-focused Kerr nonlinearity of air and defocusing produced by plasma. After that, the scientists found and researched the potential applications of femtosecond laser in many fields. The researchers found that the plasma channel is conductive, virtual, high hidden and can be released at anytime, it is a good material for RF signal transduction. In this paper, we research the use of plasma filament in this direction.Firstly, according to physical characteristics of femtosecond laser, we discuss the interaction mechanism of the plasma channel and radio frequency electromagnetic signals. Then the conductive properties of radio frequency electromagnetic wave by single plasma wire, double plasma filaments and plasma circular waveguides are studied comprehensively.Secondly, we simulate the three plasma transmission wire configuration by using High Frequency Structure Simulation software(HFSS). We got the relationship between the femtosecond laser plasma filament electron density, radius and geometrical arrangement and the reflection coefficient and transmission coefficient about single plasma wire, double plasma filaments structure and circle waveguide transmission of RF signal.In this thesis, the theoretical and experimental investigations of plasma filaments have demonstrated the unique capability of plasma transmission lines. Our work is also expected to promote the development of filament into the area of communications and electricity.