Helical Photonic Confinement of Metal Clusters Enables Switching and Imaging of Near-Infrared Circularly Polarized Light.

Near-infrared (NIR) circularly polarized luminescent (CPL) materials are highly desirable for optical communication, bioimaging, night-vision applications, and chiral encrypted information transfer, yet their practical use is limited by extremely low luminescence asymmetry factors (glum). Here, we establish a helical photonic confinement strategy by embedding NIR-emissive Au13 nanoclusters into chiral nematic mesoporous silica (CNMS). Precise matching between the chiral photonic bandgap and cluster emission yields strongly enhanced NIR-CPL with a glum of -0.4, enabling direct discrimination of left- and right-handed circularly polarized emission in the NIR region. This system realizes the first high-contrast, CPL-resolved near-infrared (night-vision) imaging based on intrinsic cluster emission, without external polarization optics. The Au13 clusters undergo reversible assembly-disassembly within helical nanochannels, allowing controllable NIR-CPL switching and handedness inversion. Mechanistic studies confirm that the CPL enhancement originates from chiral photonic propagation modulation rather than intrinsic emitter chirality. This helical-confinement principle is extendable to multicolor metal clusters, offering a general route toward high-efficiency CPL materials.