Optical spin Hall effect of polariton condensation in organic crystal microcavities.

Optical spin Hall effect (OSHE) is a typical phenomenon of the coupling of spin and orbit degrees of freedom of photons during transmission in a medium, which has significant applications in novel spin photon devices and information transmission. However, the OSHE is weak in inorganic semiconductor microcavities and usually requires an external magnetic field for enhancement, which limits its practical applications. In this work, we demonstrate the OSHE of polariton condensation in organic crystal microcavities without external magnetic field. The significant separation of left- and right-handed (σ+/σ-) circular polarization components of polariton condensate is observed in the two-dimensional (2D) momentum space and real space, which is the most notable feature of OSHE. Additionally, by adjusting the incident wavevector of the non-resonant excitation pump, the individual σ+ or σ- circular polarization components of the polariton condensate can emerge in 2D momentum space and real space. The OSHE based on polariton condensation in organic crystal microcavities without external magnetic field opens up for polariton spintronics and topological photonics devices.