Generation of largely elliptically polarized terahertz radiation from laser-induced plasma

A novel all-optical control scheme is proposed to continuously tune the THz radiation polarization, where the driving laser is based on a three-pulse configuration with adjustable time delays or intensity ratio. With this scheme, not only is the circularly polarized THz radiation realized, the continuous tuning from circular polarization to linear polarization can also be obtained conveniently just by adjusting time delays or intensity ratio. Moreover, the left or the right chirality of THz radiation can be transformed between each other with suitable time delays.