Polarization of terahertz radiation from laser generated plasma filaments

Journal Article · Sun Nov 15 00:00:00 EST 2009 · Journal of the Optical Society of America. Part B, Optical Physics

DOI:https://doi.org/10.1364/JOSAB.26.002016· OSTI ID:22046830

Dietze, Daniel; Darmo, Juraj; Roither, Stefan; Pugzlys, Audrius; Unterrainer, Karl ^[1]; Heyman, James N ^[2]

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1. Vienna University of Technology, Photonics Institute, Gusshausstr. 25-29, 1040 Vienna (Austria)
2. Macalester College, Physics Department, 1600 Grand Avenue, St. Paul, Minnesota 55105 (United States)

An analysis of the polarization of terahertz (THz) radiation from a laser-induced plasma source is presented. THz emission is achieved by mixing a laser pulse with its second harmonic after focusing through a {beta}-BaB{sub 2}O{sub 4} ({beta}-BBO) crystal. Numerical calculations, based on the nonlinear four-wave mixing model and the microscopic polarization model, are compared with experimental results. The main focus lies on the study of the dependence of THz polarization on the polarization and relative phase of the incident fundamental and second-harmonic pulses. We show that the modulation of the fundamental pulse by the BBO crystal has to be taken into account in order to describe experimental observations. By including the finite extension of the plasma and considering cross- and self-phase modulation of the two-color pump pulse, we are able to explain the observed ellipticity of the THz pulse as well as the orientation of the polarization axis.

• OSTI ID: 22046830
• Journal Information: Journal of the Optical Society of America. Part B, Optical Physics, Vol. 26, Issue 11; Other Information: (c) 2009 Optical Society of America; Country of input: International Atomic Energy Agency (IAEA); ISSN 0740-3224
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BARIUM COMPOUNDS
BORATES
COLOR
CRYSTALS
HARMONIC GENERATION
LASER RADIATION
LASER-PRODUCED PLASMA
MODULATION
NONLINEAR PROBLEMS
PHOTON EMISSION
PLASMA FILAMENT
POLARIZATION
PULSES
VISIBLE RADIATION