Abstract-Generation of Elliptically Polarized Terahertz Waves from Laser-Induced Plasma with Double Helix Electrodes

Xiaofei Luhttp://prl.aps.org/abstract/PRL/v108/i12/e123903² and X.-C. Zhang^1,2,* 
1Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
²Department of Physics, Applied Physics, and Astronomy, Center for Terahertz Research, Rensselaer Polytechnic Institute, Troy, New York 12180, USA

Received 6 June 2011; published 21 March 2012

By applying a helical electric field along a plasma region, a revolving electron current is formed along the plasma and an elliptically polarized far-field terahertz wave pattern is observed. The observed terahertz wave polarization reveals the remarkable role of velocity retardation between optical pulses and generated terahertz pulses in the generation process. Extensive simulations, including longitudinal propagation effects, are performed to clarify the mechanisms responsible for polarization control of air-plasma-based terahertz sources.

© 2012 American Physical Society

URL:

http://link.aps.org/doi/10.1103/PhysRevLett.108.123903

DOI:

10.1103/PhysRevLett.108.123903

PACS:

42.65.Re, 32.80.Fb, 52.50.Jm