Title: Classical entanglement underpins the propagation invariance of space-time wave packets Show Chinese title

Title: 经典纠缠支撑时空波包的传播不变性

Abstract: Space-time wave packets are propagation-invariant pulsed beams that travel in free space without diffraction or dispersion by virtue of tight correlations introduced into their spatio-temporal spectrum. Such correlations constitute an embodiment of classical entanglement between continuous degrees of freedom. Using a measure of classical entanglement based on the Schmidt number of the field, we demonstrate theoretically and experimentally that the degree of classical entanglement determines the diffraction-free propagation distance of ST wave packets. Reduction in the degree of classical entanglement manifests itself in an increased uncertainty in the measured spatio-temporal spectral correlations. Show Chinese abstract

Abstract: 时空波包是传播不变的脉冲光束，在自由空间中传播时由于其时空谱中引入的紧密关联而不会发生衍射或色散。 这种关联是连续自由度之间经典纠缠的一种体现。 使用基于场的 Schmidt 数的经典纠缠度量，我们理论上和实验上证明了经典纠缠度决定了 ST 波包的无衍射传播距离。 经典纠缠度的降低表现为测量的时空谱关联中的不确定性增加。