Coherent Polarization Control of Terahertz Waves Generated from Two-Color Laser-Induced Gas Plasma

Abstract

Electrons ionized from an atom or molecule by circularly or elliptically polarized femtosecond omega and 2omega pulses exhibit different trajectory orientations as the relative phase between the two pulses changes. Macroscopically, the polarization of the terahertz wave emitted during the ionization process was found to be coherently controllable through the optical phase. This new finding can be completely reproduced by numerical simulation and may enable fast terahertz wave modulation and coherent control of nonlinear responses excited by intense terahertz waves with controllable polarization.

Intense ultrashort terahertz pulses: generation and applications

“…In case of the frequently used type I SHG the polarization of the 400 nm light is mostly perpendicular to that of the fundamental. The relative electric field polarization directions can be controlled by a dual-band waveplate inserted between the SHG crystal and the focus to set them, e.g., parallel [55]. The accumulated temporal retardation of the SHG pulse with respect to the fundamental pulse due to material dispersion can be (pre)compensated by a birefringent plate such as -BBO or calcite.…”

Ultrafast Carrier Dynamics in Graphene under a High Electric Field

“…1(a). We used a collinear air plasma method for generation of intense half-cycle THz pulses [15] [ Fig. 1(b)].…”

Frequency-resolved optical gating capable of carrier-envelope phase determination

“…It is known that the intensity of the infrared pulse generated by four-wave mixing changes with a period of B200 nm by changing the delay between the fundamental and the SH of the Ti:sapphire laser output pulses 18 . The situation is similar to terahertz generation with gas plasma 22,23 . According to the references, the CEP changes by p when the delay is changed by B200 nm.…”