We report a theoretical investigation for extremely bright terahertz (THz) radiation generation by mixing of dichromatic Hermite–Cosh–Gaussian (HChG) laser beams in periodically rippled density plasma in the presence of external dc magnetic field. The magnetic field is applied perpendicular to the direction of propagation and to the polarization states of laser beams. THz field amplitude significantly increases with applied dc magnetic field. Our investigations reveal that frequency resonance shifts with the applied magnetic field. As a result, THz frequency tuning is possible with applied magnetic field. The electron neutral collisions have no effect on resonance condition but THz amplitude and efficiency decreases with increase in frequency of electron neutral collisions. We find that THz field profile strongly depends on laser parameters like Cosh decentred parameter $b$ and order of Hermite function $s$ , and independent of applied magnetic field. Our theoretical investigations predict that GV/m THz field with efficiency ~7% for laser field ~50 GV/m and 80-kG applied dc magnetic field can be obtained for optimized set of laser and plasma parameters.

中文翻译：

---

密度调制冷磁化等离子体中 Hermite-Cosh-Gaussian 激光束的混频产生太赫兹辐射

我们报告了在外部直流磁场存在的情况下，通过在周期性波纹密度等离子体中混合二色厄米-科什-高斯 (HChG) 激光束来产生极亮太赫兹 (THz) 辐射的理论研究。磁场垂直于激光束的传播方向和偏振态施加。太赫兹场振幅随着施加的直流磁场显着增加。我们的研究表明，频率共振随施加的磁场而变化。因此，可以通过外加磁场进行太赫兹频率调谐。电子中性碰撞对共振条件没有影响，但太赫兹振幅和效率随着电子中性碰撞频率的增加而降低。 $b$ 和 Hermite 函数的顺序 $s$ ，并且与外加磁场无关。我们的理论研究预测，对于激光场 ~50 GV/m 和 80-kG 施加的直流磁场，可以获得效率 ~7% 的 GV/m THz 场，以获得优化的激光和等离子体参数集。