Pinheiro da Silva Braian, Buono Wagner T, Pereira Leonardo J, Tasca Daniel S, Dechoum Kaled, Khoury Antonio Z
Instituto de Física, Universidade Federal Fluminense, 24210-346 Niterói, RJ, Brazil.
School of Physics, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa.
Nanophotonics. 2021 Nov 8;11(4):771-778. doi: 10.1515/nanoph-2021-0493. eCollection 2022 Jan.
We demonstrate the spin to orbital angular momentum transfer in frequency upconversion with structured light beams. A vector vortex is coupled to a circularly polarized Gaussian beam in noncollinear second harmonic generation under type-II phase match. The second harmonic beam inherits the Hermite-Gaussian components of the vector vortex; however, the relative phase between them is determined by the polarization state of the Gaussian beam. This effect creates an interesting crosstalk between spin and orbital degrees of freedom, allowing the angular momentum transfer between them. Our experimental results match the theoretical predictions for the nonlinear optical response.
我们展示了在频率上转换中利用结构化光束实现自旋到轨道角动量的转移。在II型相位匹配下的非共线二次谐波产生过程中，一个矢量涡旋与一个圆偏振高斯光束耦合。二次谐波光束继承了矢量涡旋的厄米 - 高斯分量；然而，它们之间的相对相位由高斯光束的偏振态决定。这种效应在自旋和轨道自由度之间产生了有趣的串扰，使得它们之间能够进行角动量转移。我们的实验结果与非线性光学响应的理论预测相匹配。
