Polygonal spatiotemporal optical vortices wavepackets with a prescribed vortex structure

Spatiotemporal optical vortices (STOVs) are a type of light beams that carry transverse orbital angular momentum (T-OAM), enabling the generation and control of additional degrees of freedom. However, the currently generated STOV wavepackets, whether with a single STOV or multiple sub-STOVs, typically exhibit a single circular symmetric structure in the spatiotemporal plane, limiting their potential in many applications. To address this limitation, we theoretically propose and experimentally demonstrate polygonal spatiotemporal optical vortices wavepackets embedded with prescribed vortex structures. Within the structure, a prescribed number of sub-STOVs carrying T-OAM is set along a designed polygonal spatiotemporal trajectory. Using the spatiotemporal holographic shaping approach, we generate a polygonal perfect STOV wavepacket and use the combination of two polygonal perfect STOV wavepackets to form a polygonal STOV wavepacket with the prescribed vortex structure. Full control over multiple key properties of the polygonal STOV wavepackets such as the geometry, number of phase singularities, and spatiotemporal distribution of sub-STOVs is also achieved. This ability provides a way to customize STOV wavepackets with complex topological structures. These spatiotemporal wavepackets will facilitate applications such as optical communication, the study of complicated quantum systems, and multiple-target particle manipulation.