Malik Anil K, Malik Hitendra K, Stroth Ulrich
Department of Physics, Plasma Waves and Particle Acceleration Laboratory, Indian Institute of Technology Delhi, New Delhi - 110 016, India.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Jan;85(1 Pt 2):016401. doi: 10.1103/PhysRevE.85.016401. Epub 2012 Jan 11.
Resonant excitation of terahertz (THz) radiation based on beating of two spatial-Gaussian lasers having different frequencies and wave numbers but the same electric field amplitudes is proposed in a spatially periodic density plasma in the presence of a static magnetic field applied perpendicular to the direction of propagation of the lasers. In this process, the ponderomotive force is developed with its components parallel and perpendicular to the direction of propagation of the lasers. This leads to a nonlinear oscillatory current that resonantly excites the THz radiation with the frequency of the order of the upper hybrid frequency. The contribution of magnetic field, laser beamwidth, and amplitude and periodicity of the density ripples is discussed for the efficient THz radiation generation. With the optimization of these parameters, the efficiency on the order of 10(-3) or larger can be achieved in the present scheme.
提出了在垂直于激光传播方向施加静态磁场的空间周期性密度等离子体中，基于两个频率和波数不同但电场振幅相同的空间高斯激光拍频来共振激发太赫兹（THz）辐射。在此过程中，产生了具有平行和垂直于激光传播方向分量的有质动力。这导致了一个非线性振荡电流，该电流以高频混合频率量级的频率共振激发太赫兹辐射。讨论了磁场、激光束宽以及密度波纹的幅度和周期性对高效太赫兹辐射产生的贡献。通过优化这些参数，在本方案中可以实现10^(-3) 或更大的效率。
