Vector beams, non-separable in spatial mode and polarisation, have emerged as enabling tools in many diverse applications, from communication to imaging. This applicability has been achieved by sophisticated laser designs controlling the spin and orbital angular momentum, but so far is restricted to only two-dimensional states. Here we demonstrate the first vectorially structured light created and fully controlled in eight dimensions, a new state-of-the-art. We externally modulate our beam to control, for the first time, the complete set of classical Greenberger–Horne–Zeilinger (GHZ) states in paraxial structured light beams, in analogy with high-dimensional multi-partite quantum entangled states, and introduce a new tomography method to verify their fidelity. Our complete theoretical framework reveals a rich parameter space for further extending the dimensionality and degrees of freedom, opening new pathways for vectorially structured light in the classical and quantum regimes.

在空间模式和偏振方向上不可分离的矢量光束已成为从通讯到成像等众多应用中的使能工具。这种适用性已经通过控制自旋和轨道角动量的复杂激光设计得以实现，但到目前为止仅限于二维状态。在这里，我们演示了在八个维度上创建并完全控制的第一矢量结构光，这是一种最新的技术。我们首次对光束进行外部调制，以控制近轴结构光束中完整的格林伯格-霍恩-策林格（GHZ）经典态，类似于高维多粒子量子纠缠态，并引入了新的层析成像方法来验证其保真度。