Nonlinear Parametric Scattering of Hybrid Exciton Polariton in a Strong Coupled Microcavity

Abstract Nonlinear parametric process plays a pivotal role in modern optoelectronics, underpinning the central role in optical amplification, quantum networks as well as entangled photon pair generation. Compared to pure photonic systems constrained by weak polarizability and stringent phase‐matching conditions, exciton‐polaritons sustain parametric scattering at significantly lower thresholds due to their strong polariton‐polariton interactions. Although polariton parametric scattering (PPS) has been reported, the deterministic generation of quantum‐correlated photon pairs remains a challenge. Here, entangled photon pair is demonstrated that generated via nonlinear PPS in microcavity, where strong coupled hybrid polaritons with three anti‐crossing eigenstates provide ideal scattering channels for PPS. The far‐field patterns demonstrate macroscopic polariton occupation of signal‐ and idler‐states, signifying the transition from Rayleigh scattering to nonlinear parametric scattering regime. Additionally, polarization and second‐order temporal correlation measurements reveal orthogonal polarization properties and quantum correlations, highlighting the potential for entangled photon pair generation. Theoretical simulations using coupled Gross‐Pitaevskii equations explore the dynamics with high fidelity. These results establish a platform for on‐demand entangled photon generation, advancing quantum polaritonics toward practical applications in quantum communication and information processing.