Related Experiment Video
Updated: Feb 15, 2026

Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters
Published on: July 8, 2013
Polarization control of terahertz radiation from two-color femtosecond gas breakdown plasma
Abstract:
We individually control polarizations of 800 and 400 nm beams, which form a two-color femtosecond plasma filament in air irradiating a linear-to-elliptical THz signal. We detected a threshold-like appearance of THz ellipticity at the angle of ∼85° between the fundamental and second-harmonic field polarization directions. The simulations confirm the abrupt change of THz polarization and reveal that the weak ellipticity of the second harmonic is sufficient to generate essentially elliptical THz radiation.
Related Concept Videos
Molecular Shape and Polarity
Group Polarization
Biological Effects of Radiation
Physical Methods for Controlling Microbial Growth: Radiation and Filtration
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
Color Vision

