Department of PhysicsThe localized plasma dipole oscillation technique was first proposed by Kwon K. et al in 2016 as an efficient terahertz radiation source [1]. This can be achieved by cross-shooting two-color ultrashort laser pulses into plasma and can be applied for diagnostic purposes as well. The ensemble of charged particles oscillating like plasma dipoles radiate EM waves at plasma frequency (??p) with the narrowband spectrum and carry meaningful information about the bulk plasma. In particular, by measuring the frequency of radiated signals, local plasma density at the focused point can be detected. Comparing the new idea with the conventionally utilized techniques such as interferometry, reflectometry, and Langmuir probes [2-4], we insist that our method has numerous advantages as a technique for measuring the density [5]. Theoretical estimations accompanied by 1D, 2D, and 3D PIC simulations indicated that embedded plasma dipole oscillators show complex behavior leading to harmonic generations and many nonlinear effects that require further investigation. In this thesis, the dipole formation, radiation scheme, and density reconstruction measurements are reported and the investigations about magnetic field effects and harmonic generations are introduced briefly.clos
