All-Optical and Ultrafast Control of High-Order Exciton-Polariton Orbital Modes.

Exciton-polaritons flows within closed quantum circuits can spontaneously form phase-locked modes that carry orbital angular momentum (OAM). With its infinite set of angular momentum quantum numbers (ℏ), high-order OAM represents a transformative solution to the bandwidth bottleneck in multiplexed optical communication. However, its practical application is hindered by the limited choice of materials which in general requires cryogenic temperatures and the reliance on mechanical switching. In this work, we achieve stable and high-order (up to order of 33) OAM modes by constructing a closed quantum circuit using the halide perovskite microcavities at room temperature. By controlling the spatial and temporal symmetry of the closed quantum circuits using another laser pulse, we achieve significant tuning OAM of EP flows from 8ℏ to 12ℏ. Our work demonstrates all-optical and ultrafast control of high-order OAM using exciton-polariton condensates in perovskite microcavities that would have important applications in high-throughput optical communications.