THz emission with X-mode laser pulses

We propose to investigate the THz emission using laser–plasma interaction, when two X-mode lasers beat and interact with inhomogeneous plasmas. Pulse steepness varies from slow rise and fall to the steep rise and steep fall in spatial electric field envelope as Gaussian pulse changes into non-Gaussian (triangular and round triangular) laser pulse. X-mode of Gaussian (G), round triangular (RT) and triangular (T) laser pulses are used to investigate the THz emission. THz amplitude varies with magnetic field, transverse distance and resonance frequency. THz radiation intensifies and attains peak value at resonance condition. For exact phase matching condition, THz efficiency of the order of 10−4 can be achieved for Gaussian pulses. X-mode lasers are more favourable to produce high-amplitude THz radiations in comparison with ordinary laser mode. Present study concludes that Gaussian and non-Gaussian laser pulses influence THz emission differently in ordinary and extraordinary laser modes. (author)