Twisted Terahertz Generation Carrying Angular momentum in plasma

Developing a low-cost and accessible methods for generating twisted terahertz light is necessary, because there are a few methods to produce torsional terahertz and also the efficiency of the methods is low. In this book a new method is proposed to generate twisted terahertz in plasma. Based on the beating of two Laguerre-Gaussian lasers in a rippled plasma medium, can be generated a nonlinear electron current. The nonlinear electron current radiates a terahertz wave having superposition of two orbital angular momenta. For having Laguerre-Gaussian profile and carrying only one of angular momenta, has been proposed a rippled density. Here the pivotal effects on the generation of terahertz radiation, such as self-focusing and cross-focusing are investigated. The propagation of twisted lasers in plasma is studied. Propagating many Laguerre-Gaussian lasers, can produce a great filamentation. The filamentation is affected by the self-focusing and cross focusing effects. As it is seen in this research, the terahertz generation is grown by these effects. Furthermore, the present study surveys the effective parameters on the generation of vortex THz radiation.