Study on Propagation Properties of 6-GHz EM Wave Along Single Laser Plasma Filament by Simulation

Research on the radiation and transmission characteristics of the electromagnetic (EM) wave along the plasma filament, especially the spatial field distribution, has not been carried out sufficiently so far. Therefore, the propagation of the EM wave along a plasma filament produced by intense femtosecond laser pulses is investigated with the EM simulation software XFDTD. The simulated results show that the plasma filament can guide the EM wave, acting as a Cu wire. Besides, one can note that the amplitude of the electric field monotonically decreases with increasing the EM wave propagation length along the filament except the terminal. We can also conclude that the wavelength of the EM wave along the plasma filament is about 4.98 cm, which is slightly less than that of the incident 6-GHz signal. Furthermore, the electric field enhancement phenomenon appears at the filament terminal due to the impedance mismatch. Finally, the direction of the electric field, the magnetic field, and the induced current around the filament is obtained. The research results show that the plasma filament can provide efficient transport of the microwave energy, which greatly reduces the diffusion attenuation in the transmission process relative to freely propagating the signal.