Integrated Multifunctional Platform with X-ray and Near-Infrared Driven Photochromic Behavior for Reversible Quad-Mode Optical Imaging

Noninvasive optical imaging techniques, including X-ray and near-infrared (NIR), hold significant value for scientific research and industrial applications. However, there is still a lack of a convenient platform that integrates X-ray imaging and NIR imaging in both bright- and dark-field applications. Here, a rare-earth ion-doped LaNbO4:Pr,Er photochromic luminescent material is developed, integrating X-ray-induced coloration, NIR-induced bleaching, photoluminescence, and luminescence modulation. Under alternating X-ray and NIR light irradiation, the reflectivity and luminescence intensity can be reversibly tuned to display four optical states: white, black, dark, and bright. By utilizing the switchable optical states, quad-mode imaging of X-ray and NIR in bright and dark fields is achieved. NIR-induced photobleaching imaging, when employed as adjuncts to X-ray-induced photochromic imaging, has the potential to significantly reduce radiation-induced damage to biological tissues. These results provide unique insights for designing advanced materials and photonic storage technologies toward advanced multiwavelength, multienvironment, and multimode noninvasive imaging.