Nagai Kohei, Okamoto Takuya, Shinohara Yasushi, Sanada Haruki, Oguri Katsuya
NTT Basic Research Laboratories, NTT Corporation, 3-1, Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
NTT Research Center for Theoretical Quantum Information, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
Sci Adv. 2024 Aug 2;10(31):eado7315. doi: 10.1126/sciadv.ado7315.
Symmetries essentially provide conservation rules in nonlinear light-matter interactions and facilitate control and understanding of photon conversion processes or electron dynamics. Since anisotropic solids have rich symmetries, they are strong candidates for controlling both optical micro- and macroscale structures, namely, spin angular momentum (circular polarization) and orbital angular momentum (spiral wavefront), respectively. Here, we show structured high-harmonic generation linked to the anisotropic symmetry of a solid. By strategically preserving a dynamical symmetry arising from the spin-orbit interaction of light, we generate multiple orbital angular momentum states in high-order harmonics. The experimental results exhibit the total angular momentum conservation rule of light even in the extreme nonlinear region, which is evidence that the mechanism originates from a dynamical symmetry. Our study provides a deeper understanding of multiscale nonlinear optical phenomena and a general guideline for using electronic structures to control structured light, such as through Floquet engineering.
对称性本质上为非线性光与物质相互作用提供了守恒规则，并有助于控制和理解光子转换过程或电子动力学。由于各向异性固体具有丰富的对称性，它们分别是控制光学微观和宏观结构（即自旋角动量（圆偏振）和轨道角动量（螺旋波前））的有力候选者。在此，我们展示了与固体各向异性对称性相关的结构化高次谐波产生。通过策略性地保留由光的自旋 - 轨道相互作用产生的动态对称性，我们在高次谐波中生成了多个轨道角动量态。实验结果表明，即使在极端非线性区域，光的总角动量守恒规则依然成立，这证明该机制源于动态对称性。我们的研究为多尺度非线性光学现象提供了更深入的理解，并为利用电子结构控制结构化光（如通过弗洛凯工程）提供了通用指导方针。
