Chirality Switching of Amplified Spontaneous Emission in Halide Perovskites via Motor-Doped Chiral Liquid Crystals

Circularly polarized (CP) coherent light sources are pivotal for advanced photonics, including chiral sensing, spin-optoelectronics, and quantum communication. However, achieving dynamic and reversible control over their chirality remains challenging. Here, we demonstrate a chirality-invertible CP light source by integrating a photoresponsive cholesteric liquid crystal (CLC) modulation layer with a polycrystalline perovskite gain medium. Under ultraviolet irradiation, the CLC layer undergoes reversible handedness inversion, enabling dynamic switching of the chirality of the perovskite’s amplified spontaneous emission (ASE). The device features switchable CP-ASE with a tunable circular polarization dissymmetry factor (glum) ranging from −1.38 to +1.22. Furthermore, broadband CP-ASE emission from green to near-infrared is achieved by tailoring the perovskite halide composition. This work presents a versatile strategy for fabricating reconfigurable CP light sources, offering new avenues toward spin-polarization switchable chiral laser devices.