Spatiotemporal topological combs for robust high-dimensional information transmission

Time-varying orbital angular momentum (OAM) beams are fascinating due to their rich physics and essentially unbounded degrees of freedom. Yet, despite this promise, their practical use in high-capacity communication has not been demonstrated. We introduce a spatiotemporal topological comb (ST-Comb) as a programmable information carrier in which digital data are encoded into a generalized spatiotemporal-topological state space, rather than into a single vortex beam or an OAM mode. The accessible states are defined by temporal slots, spatiotemporal phase winding, radial topology, coherent topological superpositions, and ST-CEP-dependent spectral fingerprints.
A Hyper-DoF ST-Comb modulator programs these variables in the kx-ω plane, while a selfreferenced Guide-Star pulse enables coherent reconstruction relative to an intrinsic optical reference. In the present proof-of-concept, we demonstrate 154 mapped digital bits per wavepacket, recovered with 100% recognition accuracy under tested laboratory, phase-screen-equivalent turbulence, and 100 m outdoor field-trial conditions. The results chart a path toward reconfigurable ultrafast photonics, where programmable spatiotemporal-topological states provide a robust physical alphabet for high-dimensional optical interconnects.