Abstract-Terahertz radiation generation by propagation of circularly polarized laser pulses in axially magnetized plasma

Pooja Sharma, Navina Wadhwani, and Pallavi Jha

http://aip.scitation.org/doi/10.1063/1.4973325

An analytical study is developed for the generation of terahertz radiation by propagation of a circularly polarized laser pulse in axially magnetized plasma, in the mildly relativistic regime. A perturbative technique is used to obtain the electric and magnetic wakefields within and behind the laser pulse. The emission of terahertz radiation via generated transverse wakefields is analyzed by determining mutually perpendicular electric and magnetic wakefields oscillating at the plasma frequency and having the same amplitude. It is shown that the generated transverse electric and magnetic wakefields constitute two off-axis, linearly polarized terahertz electromagnetic fields propagating along the laser pulse direction.

Abstract-Tunable Circularly Polarized Terahertz Radiation from Magnetized Gas Plasma

W.-M. Wang, P. Gibbon, Z.-M. Sheng, and Y.-T. Li

Phys. Rev. Lett. 114, 253901 – Published 23 June 2015

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.253901

It is shown, by simulation and theory, that circularly or elliptically polarized terahertz radiation can be generated when a static magnetic (B) field is imposed on a gas target along the propagation direction of a two-color laser driver. The radiation frequency is determined by ω2p+ω2c/4−−−−−−−−√+ωc/2, where ωp is the plasma frequency and ωc is the electron cyclotron frequency. With the increase of the B field, the radiation changes from a single-cycle broadband waveform to a continuous narrow-band emission. In high-B-field cases, the radiation strength is proportional to ω2p/ωc. The B field provides a tunability in the radiation frequency, spectrum width, and field strength.

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