Chiral polariton transport enabled by optical spin Hall effect in perovskite waveguides.

Controlling the spin degree of freedom of light at the microscale is crucial for advancing photonic information processing. Spin-polarized light propagation, combined with strong optical nonlinearities, unlocks new functionalities in compact photonic circuits and active spin-optronic devices. Lead halide perovskite exciton-polaritons uniquely combine room-temperature operation, pronounced nonlinearities, and versatile microstructuring, making them a powerful platform for spin-based photonic technologies. Here, we demonstrate polarized edge emission from polariton condensates in perovskite single crystals predesigned into a microwire, forming natural, DBR-free cavity. Above threshold, we observe a distinct waveguiding optical spin Hall effect pattern in both real- and reciprocal-space emission, accompanied by pseudospin phase-locking arising from coherence between opposite edges. Beyond static polarization textures, we achieve spin-resolved polariton edge lasing with chirality exceeding 80% and spin-polarized signal propagation over tens of micrometers. These results establish CsPbBr3 waveguides as a promising easy-to-fabricate platform for on-chip spin-coded information transport and nonlinear spin-optoelectronics.