Ferroelectric Interfacial Charge Reconfiguration Programs Excitonic Polarization Anisotropy for Multiplexed Optical Readout

ABSTRACT Polarization, a fundamental degree of freedom of light, underpins advanced optical technologies ranging from optical communication to information encoding because orthogonal polarization states are intrinsically robust against amplitude noise. Yet achieving electrically tunable and nonvolatile polarization light control at the micro‐ and nanoscale remains a major challenge because of stringent symmetry requirements and the scarcity of suitable material platforms. Herein, we present an electrically reconfigurable polarization–modulation scheme based on a WSe 2 /CuInP 2 S 6 (CIPS) device. The interfacial coupling between monolayer WSe 2 and ferroelectric CIPS breaks the in‐plane symmetry of WSe 2 , leading to polarization‐sensitive emission. Furthermore, by utilizing the bistable ferroelectric polarization of CIPS, which arises from reversible Cu + displacement, we show that the emission polarization angle can be programmed in a nonvolatile manner, achieving a tunable rotation of ∼8° between oppositely polarized states. First‐principles calculations further indicate that ferroelectric Cu + displacement reversibly reshapes the interfacial charge landscape without substantial reconstruction of the WSe 2 band dispersion, supporting interfacial charge reconfiguration as the microscopic basis for the programmable excitonic polarization response. These findings establish ferroelectric interfacial charge reconfiguration as a deterministic and nonvolatile mechanism for programmable excitonic polarization control, opening a route toward polarization multiplexed optical readout and reconfigurable integrated polarization photonics.