Optical spin Hall effect pattern switching in polariton condensates in organic single-crystal microbelts

Topological polaritons, combining the robustness of the topological protected edge states to defects and disorder with the strong nonlinear properties of polariton bosons, represent an excellent platform to investigate novel photonic topological phases. In this work, we demonstrated the optical spin Hall effect (OSHE) and its symmetry switching in the exciton-polariton regime of pure DPAVBi crystals. Benefiting from the photonic Rashba-Dresselhaus spin-orbit coupling in organic crystals, we observed the separation of left- and right-circularly-polarized polariton emission in two-dimensional momentum space and real space, a signature of the OSHE. Above the lasing threshold, the OSHE pattern changes due to transverse quantization in the microbelt. This device without superlattice structure has great potential applications in topological polaritonics, such as information transmission, photonic integrated chips and quantum information.