Research on the Propagation Characteristics of THz Waves in Spatial Inhomogeneous and Time-Varying and Weakly Ionized Dusty Plasma

Dusty plasma differs from ordinary plasma, and its unique properties have always been an active research branch of plasma science. In this article, a finite-difference time-domain (FDTD) method is used to study the propagation characteristics of terahertz (THz) waves in spatially inhomogeneous and time-varying weakly ionized and weakly colliding dusty plasma. The reflection and transmission coefficients are analyzed for the concentration and radius of dust particles, the time-varying rate of electron density, and the effective collision frequency. Results show that increasing the concentration and radius of dust particles will enhance the adsorption ability of the dust particles toward electrons, thereby weakening the electron density in dusty plasma, which will increase the penetration ability of THz waves into the dusty plasma layer. The increase in the effective collision frequency in the dusty plasma will enhance the collisional absorption of dusty plasma and restrain the ability of electromagnetic (EM) waves to penetrate the plasma layer. However, the ability of EM waves to penetrate the dusty plasma layer can be effectively improved by increasing incident wave frequency. Therefore, using THz technology to penetrate spatially inhomogeneous and time-varying dusty plasma is feasible.