论文标题
相对论振荡窗口中光的高谐波产生和旋转轨道相互作用
High-Harmonic Generation and Spin-Orbit Interaction of Light in a Relativistic Oscillating Window
论文作者
论文摘要
当高功率激光束在固体箔靶上辐照一个小光圈时，强的激光场在该孔的周围驱动表面等离子体振荡，该孔径充当“相对论振荡窗口”。通过这种孔径传播的衍射光包含基本激光频率的高弹药。当驱动激光束圆两极化时，高谐波产生（HHG）过程有助于将基本光的自旋角动量转化为谐波的内在轨道角动量。通过理论建模和完全3D粒子中的模拟，显示了$ n $的谐波光束是带有拓扑电荷$ | l |的光学涡旋。 = n-1 $，以及幂律频谱$ i_n \ propto n^{ - 3.5} $是为足够强烈的激光束生产的，其中$ i_n $是$ n $ th谐波的强度。这项工作为产生强烈的极端紫外线涡流以及基于相对论强度的基于衍射的HHG研究开辟了一个新的可能性领域。
When a high power laser beam irradiates a small aperture on a solid foil target, the strong laser field drives surface plasma oscillation at the periphery of this aperture, which acts as a "relativistic oscillating window". The diffracted light that travels though such an aperture contains high-harmonics of the fundamental laser frequency. When the driving laser beam is circularly polarised, the high-harmonic generation (HHG) process facilitates a conversion of the spin angular momentum of the fundamental light into the intrinsic orbital angular momentum of the harmonics. By means of theoretical modeling and fully 3D particle-in-cell simulations, it is shown the harmonic beams of order $n$ are optical vortices with topological charge $|l| = n-1$, and a power-law spectrum $I_n\propto n^{-3.5}$ is produced for sufficiently intense laser beams, where $I_n$ is the intensity of the $n$th harmonic. This work opens up a new realm of possibilities for producing intense extreme ultraviolet vortices, and diffraction-based HHG studies at relativistic intensities.
