Tunable terahertz radiation generation by nonlinear photomixing of cosh-Gaussian laser pulses in corrugated magnetized plasma

This paper presents a scheme of THz generation by nonlinear photomixing of two cosh-Gaussian lasers pulses having different frequencies (omega(1), omega(2)) and wave numbers ((k) over right arrow (1), (k) over right arrow (2)) and same electrical field amplitude in a corrugated plasma embedded with transverse static magnetic field. Cosh-Gaussian laser pulses have steep gradient in intensity profile along with wider cross-section, which exerts a stronger nonlinear ponderomotive force at omega(1) - omega(2) and (k) over right arrow (1) - (k) over right arrow (2) on plasma electrons imparting a nonlinear oscillatory velocity to plasma electrons. Oscillatory plasma electrons couple with the density ripple n' = n(alpha 0) e(i alpha x) to produce a nonlinear current, which is responsible for resonant THz radiation at frequency similar to (omega(2)(c) + omega(2)(p))(1/2). The amplitude, efficiency and beam quality of THz radiation can be optimized by choosing proper corrugation factor (alpha of the plasma), applied magnetic field (omega(c)), decentered parameter (b), and beam width parameter alpha(0) of cosh-Gaussian lasers. An efficiency of similar to 10(-2) - 10(-1) is achieved for laser electric field E = 3.2 x 10(9) V/cm.