Effect of DC electric field on THz radiation field and efficiency of dark hollow laser beam in plasma

In the present study, a schematic has been proposed for generating terahertz (THz) radiation by beating of two dark hollow (DH) laser beams in plasma when a DC electric field is applied with a perpendicular direction. The small field amplitude and the radiation’s efficiency produced by DH laser beams in plasma as well as DC electric generation and exertion comfortability motivated us to enhance these parameters by applying a perpendicular DC electric field. It was found that applying a DC electric field in addition to increasing the THz field amplitude and efficiency caused the generation of a special THz field, which has an exclusive pattern tunable by the variation of the electric field amplitude. It is shown that due to mutual effects between the spatial profile of the beams and the electric field, the THz radiation field and efficiency have the maximum point that can be used for the production of a desired THz frequency.