全光自旋选择性频率转换路径的控制与整形
All-optical spin-selective control and shaping of frequency conversion pathways
- Tel-Aviv University（特拉维夫大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文利用光学自旋与晶体对称性相互作用，在铌酸锂薄膜中实现自旋选择性频率转换路径切换，并建立自旋-频率映射，实现全光可编程非线性信号操控。
AI中文摘要：
光学自旋与晶体对称性之间的相互作用为控制光与物质相互作用提供了强大的机制，推动了成像、全息、传感、信号处理等领域的发展。本文揭示，这种相互作用还可被用作一种可编程机制，用于选择和整形非线性频率转换路径。利用z切铌酸锂薄膜，我们实验演示了互补三波混频路径之间的自旋选择性切换，其中同旋和交叉圆偏振激发分别激活和频与差频产生。我们进一步推广这一概念，建立了定量的自旋到频率映射，将泵浦自旋组成编码到产生的频率中，并能够反向恢复泵浦自旋状态。最后，我们还利用这一概念演示了将自旋图案映射到频率相关的实空间图像和傅里叶空间衍射图案的组合。这些结果为自由空间和集成光子系统中全光可编程频率转换及时空非线性信号操控铺平了道路。
英文摘要：
The interplay between optical spin and crystal symmetry provides a powerful mechanism to control light-matter interaction, enabling advances in imaging, holography, sensing, signal processing, and more. Here we reveal that this interplay can also be exploited as a programmable mechanism for selecting and shaping nonlinear frequency-conversion pathways. Using a z-cut lithium niobate thin film, we experimentally demonstrate spin-selective switching between complementary three-wave mixing pathways, where co- and cross-circular-polarization excitations activate sum- and difference-frequency generation, respectively. We further generalize this concept to establish a quantitative spin-to-frequency mapping, that encodes the pump spin composition into the generated frequencies, and enables the reverse retrieval of the pump spin state. Finally, we leverage this concept also to demonstrate mapping of spin patterns to a combination of frequency-dependent real space images, and Fourier-space diffraction patterns. These results pave the way for all-optical programable frequency-conversion and spatiotemporal nonlinear signal manipulation in free-space and integrated photonic systems.
